What's new?  

Item	yymmdd	Comment and links
Whitepaper: GA-Prediction vs Measurements how close can they be?	v5 221006 v1 211212 (sticky)	GA-Prediction_vs_Measurements_how_close_can_they_be.pdf
A last user mass e-mail was sent out during the 2nd week in Nov 2021. For those that have not updated their contact mail addresses the PDF referred to in the last mail can be UnCTT-ed and accessed to the right. This last mail also offers new license options to use the software at home or  remote (the original license is a site license that allows for use only at a licensed office)	211108 (sticky)	Last user mass e-mail in CTT-format If you are new to the CTT-format, also used for updates and more: You may have to use a right mouse button Save Link As (or similar) rather than just click on the link since some browsers will then assume it is a text-file. Once downloaded just double-click the CTT-file and an extraction dialog appears. If you don't have proper installation you will instead have to run UnCTT.exe from the CATT-Acoustic installation folder and Browse for the CTT-file. In spite of what UnCTT says this CTT-file will not require an up-to-date license to extract but only a valid one.
On publications that totally, or almost totally, are based on GA software use	v9 250423 v1 210322 (sticky)	GA-software use publications.pdf
What is Geometrical Acoustics? (generic version)	210808 (sticky)	From 2018 a special whitepaper where the crucial Geometrical Acoustics (GA) is revisited and discussed is referred to in the TUCT™ v2 manual ([WhatIsGA?]  in Section 6. Literature references). There is now a generic version available for users with older versions, or other interested parties, that does not include any direct manual references.
A problem found with TUCT2 Predict SxR Algorithm 2	240826	A problem has been found when using TUCT2 Predict SxR Algorithm 2 (A2) (TUCT1 is no longer developed). The problem shows itself at the high frequency T-30  and T-20 values (4 to 16 kHz) being too long as if the air absorption has not been fully applied. The problem is benign in the sense that software users, that are assumed to have a good background and experience in acoustics, will see that it is an unrealistic result. It was not a problem that was easy to find the reason for and required a high amount of calculations of many cases. A further reason why it has not been realized sooner is that A2 seldom is needed and the problem does not even appear in all A2 runs. The likelihood for it happening is higher the more memory a case needs since then a slightly different reflection IR creation method is used that needs less memory but is a bit slower. It may mean that if e.g. many receivers are used in a room with a long T-30  (many long IRs)  the problem occurs while if using less receivers it does not. To test a quick run with few rays can be used. If many receivers are needed then Map measures may be more useful. The decision to create a more correct impulse response (for auralization), where for every single reflection a reflection impulse response is created, required much more complex code not necessary for the cruder method used by all, or almost all, other similar software where energy reflections are first summed in say 3 ms time-buckets and from that a crude impulse response (at e.g. 44.1 kHz) is magically created. In no case have I seen e.g. C-80 from this type of IR compared to a C-80 from the originally predicted energy echogram and it may be so that “what you see (the energy echogram) is not  what you hear (the synthesized IR)”. In TUCT this fundamental difference, especially at low frequencies (h vs E), is clearly displayed. A2 is only needed in say < 5% (or even < 1%) of all closed rooms but even then Algorithm 1 (A1) may be better since it is easier to understand and e.g. if too few rays have been used it will be clearly seen in echogram and decays. Since A2 typically takes much longer there is also a risk that too few rays instead will be used. The TUCT manual gives this central advice: Note: A good way to think when selecting algorithm is that if A1, even with many rays, does not give realistic decays and gives unnatural reverberation when auralizing it is not sufficient. And the opposite, if A2 takes a very long time as compared to A1, A2 is likely severe overkill. To always use A2 "to be sure" will only create unnecessarily long calculations, had it always been needed there would not have been an A1 at all. The problem is fixed in TUCT2 v2.0h that was released Sept 24, 2024.
CATT-Acoustic v9.1g with TUCT v2.0h ** Released **	240904	TUCT v2.0h Three new and unique Show2D displays based on B-format IRs are added: [Measure] T-30 WXYZ and T-20 WXYZ and [Echogram] Schröder WXYZ that essentially are of educational nature that clearly show if a room is non-diffuse and also why. It seems apparent that more and more non-diffuse rooms are creatated and several times it has been assumed that when T-30 becomes >> Sabine it is a software error that has to be "fixed". The problem is compounded by other software that actually gives T-30 = Sabine in these rooms. The dedicated docs (v2) for these display options, and non-diffuse rooms in general, can be found here: http://www.catt.se/Tnn-WXYZ.pdf Correction of the Algorithm 2 problem described above (240826). Misc. minor additions and maintenance
CATT-Acoustic v9.1g with TUCT v2.0g	220331	v9.1g CATT-A Plinfo.PL9 shows the total effective scattering (surface scattering + auto-edge) for each surface. An option to change RefRT in TUCT2. Misc. minor additions and maintenance
New instrument directivities CIF-files	210727	A number of high quality instrument directivities in CIF format are now available at the CLF site.
ReflPhinder™ v2 .0f separate update/fix	210422	This is a separate update of ReflPhinder v2.0d,e for full version users with free updates to 190420 and concerns correction of handling the AmbiX B-format option that came with v2.0d. Download CTT-file, UnCTT and run the resulting EXE
CATT-Acoustic v9.1f with TUCT v2.0f	201030	v9.1f Use of the new Common Instrument Format (CIF) based on the Common Loudspeaker Format (CLF) principles but made for the directiviy of natural sources such as musical instruments, human talkers and singers, noise sources etc.  Due to a large amount of unexpected work because of the pandemic the required free updates date was set to when the original v9.1f release was planed, 200301.
v9.1e:1/TUCT v2.0e maintenance	190627	v9.1e:1.02 maintenance CATT-Walker™ v2.0e also allows walking along a straight line of receivers better adapted for very large geometries
CATT-Acoustic v9.1e with TUCT v2.0e	190425	General  additions to make network use more practical CATT-A and TUCT2 switches to PDF-only help by a constantly up-to-date PDF manual that allows context sensitive help similar to the previous CHM Help-file CATT-A creation of sector directivity-files (.SDX) as a replacement for the SECTOR0 SD2 (DLL-interface) also having synthetic perfect cookie-cut directivities but that can be used with TUCT2 help on the old source-format for TUCT1 is not included in the >= v9.1e PDF manual but has been moved to a separate PDF. TUCT2  support of the sector directivity (.SDX) introduced with CATT-A v9.1e. Suggest number rays has been a decent start for rooms with good acoustics but since so many, especially but not only new users, now seem to only use Suggest and do not study the resulting echograms and decays, or listen to the IRs, many predictions are now likely to have been very insufficient. Due to this the Suggest number of rays will now be increased by four room and input-data dependent factors. TUCT1 as TUCT2 changed Suggest number of rays (in TUCT1 called Auto)  ReflPhinder™ v2.0d opening also Ambix format files and reading WXYZ also from high order files. GratisVolver™ v2.0d minor additions
CATT-Walker™ v2 .0c separate update/fix	181115	This is a separate update of CATT-Walker v2 that fixes a potential problem where the settings selected did not always take effect. This update can be installed by aynone with the full auralization license with free updates to 170309 (when Walker v2 was released with v9.1b) or later. Download CTT-file, UnCTT and run the resulting EXE
CATT-Acoustic v9.1d with TUCT v2.0d	181106	CATT-A A ceiling loudspeaker array creation tool for voice evacuation systems. Based on a desired loudspeaker spacing the tool calculates the positioning and displays coverage contours. When a satisfactory solution has been found a correponding source-file is created. A more practical extension of the originally limited Directivity module File | New Directivity | Array-format (CTA) in the form of template CTA-files that are loaded from a "CATTDATA"\SD\ CTA-Templates folder and where each file may have dedicated help associated. Warning for high flat scattering (not physical) TUCT2  Main:Show 3D: Cut z to exclude from viewing planes and edges above a selected height Addition of the G-80 measure to both Predict SxR and Map measures. Utilities | SxR Save | Impulse Responses a new option to only save source sum IRs Direct sound SPL for arrays shown on Predict SxR SPL graphs (previously only for single sources) EDT, T-15, T-20, and RT´ (like with T-30 )shows Sabine and Eyring RTs  and RefRT for reference (both are optional) Utilities | ?x? Measures | Show Graphs: clearer display with many receivers and EDT, T-15, T-20 and RT´ also optionally shows Sabine and Eyring RTs and RefRT for reference Utilities | ?x? Measures | Show Graphs: optional connecting the dots. Utilities | ?x? T-nn Statistics now has showing Sabine and Eyring RT curves optional. File | Load Old Results: if a TUCT1 result is selected it will optionally load TUCT1 with the CAM or CAP (previously only the CAG-file).  TUCT1 File | Load Old Results: if a TUCT2 result is selected it will optionally load TUCT2 with the CAM or CAP (previously only the CAG-file).  ReflPhinder™ v2.0c GratisVolver Pro™ v2.0c
A privacy handling section has been added	180801	How user data and user models are handled.
CATT-Acoustic v9.1c with TUCT v2.0c	180514 inital 180509	Note: the inital release 180509 gave problems when creating the new CAG-file format for TUCT2 related to the auto-edge scattering addition. If you installed the inital update (and then have CATT-A v9.1c:1.01, see Help | About) download and install the corrected update. CATT-A A possibility to get correct auto-edge scattering if an occasional plane is unnecessarily divided into sub-planes (such as triangles), if it concerns many planes us the plane merge option as before. A File | Preferences option to use either feet or meter for room geometry-related displays TUCT2 Utilities | ?x? Measures | Show Graphs for Meas vs r and Meas vs log2(r) also shows the receiver ids at the bottom of the graph. The Fast curve drawing option is now only marginally faster so it is more a matter of choosing the visually most appropriate display A File | Preferences option to use either feet or meter for room geometry-related displays and exports (room geometry, source and receiver positions, surface areas, room volume, mfp etc.) Utilities | ?x? T-nn Statistics has mouse max/range scaling similar to Show 2D: (Predict SxR Results) Measure / Type. The previous option to hold Ctrl to keep the scale with Ref RT on/off is no longer needed. GratisVolver Pro v2.0a (full version) an enhanced licensed version of the free GratisVolver included with CATT-A  v9.1c:1 and can be loaded from CATT-A File | External CATT Tool ReflPhinder v2.0a (full version) Filter has an 5.6 kHz low-pass filter option intended to filter away high frequencies that will for most B-format microphones disturb the localization Balloon at marker Width will change the width with 1 ms instead of 0.1 ms if Ctrl is held down when clicking +/- File | Open Stereo IR where the IR used for Schröder and measures is an L+R mix. L+R, L and R can be viewed and L+R and Stereo IRs can be played and convolved with. Results from a stereo IR are not be compared with omni mic results but are still useful With File | Open Mono IR and Open WAV-file Stereo IR the lower graph is not used but displays symbolic room graphics with a loudspeaker, mono or stereo microphones. At startup before any file has been loaded a symbolic B-format microphone setup is displayed. Faster curve-drawing. Options | Fast Curve Draw on/off will not differ much in speed but typically a room impulse will be visually clearer with fast curve draw on.  Edit | Copy Measures copies calculated measures for all bands TAB-delimited for pasting into a spreadsheet. More background information added. The mic used (B-format W, mono or stereo) is indicated along with calculated measures. All options on the Options menu are saved at exit (previously only the Font Sizes) Forward integrated curve added to the upper display View options
CATT-Acoustic v9.1b:2 with TUCT v2.0b:2	180124	CATT-A An option to use a source-file template when creating a new project TUCT2 Algorithm 1 has an average/loop option for the echogram (E). It is better to average 10 echograms than to run 10 times and average the results.  (Predict SxR Results) Measure / Type has three mouse scaling options (for measures that are not naturally using a fixed scale, such as STI) to make comparison between different SxR easier. ReflPhinder v1.2a (full version) Options | Font Sizes will when a new font/size is selected restart and apply the changes. Options | 1/1-Octave filter | Linear Phase FIR is now the default choice and the FIR longer to better suppress any noise or artifacts below the lower limit of the 125 Hz 1/1-octave band.  The Filter compensation (FC) on/off option is removed and the compensation is always on, with the longer FIRs it is necessary.
Addendum for v9.1b updated	170729	The Manual addendum for v9.1b was never updated as PDF, it can be downloaded (and for v9.1b users UnCTTed and placed in your CATT-folder to be viewed via the Help menu)
v9.1b maintenance update	170630	A fix for use of CF1/CF2-files with the powered (and sometimes active) type that have no standard Sensitivity given. Related to that a Directivity module File menu addition to simplify creating a one- element CTA-file from a loaded CF1/CF2-file where an equivalent Sensitivity can be given based on other CLF-file or manufacturer information.
Fix of a "false positive" virus "detection"	170419	A small exe in v9.1 (resample.exe) has been flagged by a few anti-virus software (but not by any of the four used to check the installations before upload) that had to do with one version of the compiler used (only for this program). This exe had been used for four years during v9.1 development and beta and since release March 2016 and has never given any actual problems. All installations and updates have been updated to include a new version (simply recompiled with a later version of the compiler concerned) and AV software no longer think it is a virus. If you missed this one and have v9.1b:1 or  v9.1a please contact CATT  for a new resample.exe
CATT-Acoustic v9.1b:1 with TUCT v2.0b	170310	CATT-Walker™ v2 based on the 3D-viewer, audio processing rewritten from scratch and many new options added. A detailed preview and beta testing was offered via the user mailing-list. CATT-A "Lower edge" 1/3-oct air absorption optionally used for the 1/1-oct estimated air absorption for  > 1kHz. CTA format adds a show option to the STRINGS block  Directivity Index (DI) shown as a graph instead of a table A dB-range option (30..60 dB) on the directivity Polar option dialog TUCT2 A full implementation in Predict SxR of ISO 3382-3 Spatial decay measures (D2,S etc.) for open plan offices to complement the more flexible option with Map measures. Allows for many recever lines to be evaluated and back- ground noise variation ISM shows 1st and 2nd reflection point coordinates after the plane id of the reflection plane.  ISM reflection time Color option is extended from only a 20 ms step to have 5, 10, 20 or 50 ms step options. 250707: this experimental option is no longer available due to very low interest and very high complexity of implementation and acquiring meaningful input data. A non-official full implementation of angle-dependent absorption. Due to the uncertainties of the benefit when only the energy absorption coefficients are known this option is intended for testing and feedback to be able to give good future recommendations, to test this hidden option contact CATT. The former Utilitiy T-30 Statistics can now also give T-15 and T-20 statistics Shows Sabine and Eyring (and optionally Tref) also on T-15 and T-20 graphs MultiVolver WCP v1.0f will, after successful processing, document the settings and the MVF-file used in a text-file. For full details download the new v9.1 Addendum
CATT-Acoustic v9.1a:1 with TUCT v2 maintenance update (.03)	160421	Update were announced over the mailing-list and if missed contact CATT. Maintenance: TUCT2 use of MICSENSITIVITY and an unusual Predict SxR algorithm 2 and 3 problem (one case found), for more info see see the bug-list.
CATT-Acoustic v9.1a:1 with TUCT v2 maintenance update (.02)	160322	Included with the .03 maintence above Maintenace: TUCT2 Predict SxR algorithm 2 and 3 problems in some cases, for more info see see the bug-list.
CATT-Acoustic v9.1a:1 with TUCT v2 ** Released **	160212	Update was announced over the mailing-list and if missed contact CATT. Basic news is here, detailed previews and a beta was offered via the mailing-list
TUCT v1.1a:4 update including CATT-A v9.0c:3	150211	Fix: TUCT v1.1a:4. In a few cases an early buildup has been observed in the impulse response (h) using Predict SxR algorithm 1 (also when using split > 0). This behavior is corrected. Additions: Prefs option to select dialog font type and size (thereby also changing the dialog size) Prefs option to select graphics font size Update was announced over the mailing-list and if missed contact CATT.
TUCT v1.1a:3 maintenance update corrected	140807	Previous maintenance fix: TUCT v1.1a. Minor diffraction issues when modeling side-by-side planes instead of modeling the intended way using sub-divisions. Minor addition: Time Trace Save AVI uses a well working compression, see Help for further details. Update was announced over the mailing-list and if missed contact CATT.
"Reverberation time, diffuse reflection,  Sabine, and computerized prediction" Part I and II	140428	This is an on-line article originally published at the RPG Diffusors Inc. web-site in 2002. The paper covers in more detail the topic in FAQ 3 and the principles hold also for v8 and v9 with TUCT.
TUCT v1.1a:3 maintenance update see above	140326	This maintenance did not actually include v1.1a:3 but still v1.1a:2 (but full updates and installation included  v1.1a:3). Use the corrected update above.
Update and maintenance of the Tannoy_CATT DLL for modeling of QFlex arrays.	Refreshed 130611 130521	UnCTT and unzip into your "CATTDATA"\Sd2Data\Tannoy_CATT folder. Update for users with unexpired free updates (handles the QFlex 64 array): (the updated DLL will be included in future updates and releases). Maintenance for users that have this DLL but have expired free updates:
TUCT v1.1a:2 maintenance update including CATT-A v9.0c:2   TUCT v1.0 h, g maintenance updates	130417	Minor additions to CATT-A v9.0c:2: Scale and viewing options in Interactive RT estimation making it easier to compare different absorption and/or scattering cases side by side (the options are kept across estimations). Sab/Eyr and 8k/16k is optional to display. Audience mapping planes do not have to be specified (if no mapping is to be done) Selecting source aim as a receiver position, for example A0  0  3  2 speaker.SD1 rec(13) where the source will be aimed at receiver 13.  For further details see Help | View Manual Addendum after installation.
CATT-Acoustic v9.0c release including TUCT v1.1a with diffraction TUCT v1.0 h, g, f maintenance updates	121122	Brief info, for further details see Help | View Manual Addendum after the update or first UnCTT Addendum v9.pdf: TUCT: A comprehensive treatment of early diffraction using a secondary edge-source method based on a discrete Huygens interpretation of Biot-Tolstoy. As a background a 20+ page whitepaper document is included in the documentation and discusses the implementation as well as diffraction in general. The white paper explains why this particular implementation was chosen instead of a screen formula that has many limitations and questionable applicability in room acoustics. The chosen implementation also gives considerably more than a screen formula could such as more correct reflections from small surfaces and also helps modeling concave and convex curved surfaces approximated by facets. Although the background is complex using diffraction in predictions is simply made via selecting it in the Predict SxR and Map measures settings dialogs and in the Diffraction options dialog which combinations to include. Still, diffraction is a very fundamental part of acoustics so the principles need to be well understood. Open-plan office measures DL2 and DLf application notes updated with remade examples and the effect of diffraction. To enable special tests and investigations it is possible to select a combination of early sound, including diffraction,  by entering 0, 1, 2 or 3 as Number of  rays/cones in Predict SxR and Map measures settings dialogs. Map measures results have a new Type Spectra were the total SPL 1/1-octave spectrum as well as the SPL 0..10 ms and 0..50 ms are shown for each map point when the Shift key is held and the mouse is moved over the map (i.e. similar to the Echograms option). Map measures map point coordinate mouse-over display Map points optionally shown with (Audience mapping) / Surfaces New mapping palette options (selected in Preferences): A smoothly modulated palette named R-G-B Modulated and a user-defined monochrome palette that goes from light to dark color named Color Luminosity Some export additions: Tref, TSabine and TEyring Utilities menu export of Predict SxR results will export modified STI and U-50 results. In previous versions text and MATLAB export did not export the effects of changed background noise or overall SPL change (Eqx) from Predict SxR but used the originally given data. Due to this the MATLAB export has some changed and new variables: Predict SxR LF is now calculated both for E and h and the previous h-based LF has been corrected (see below) Optional grid on Show 2D Plan/Section (selected in Preferences) Explicit selection of number of threads to use in processing (selected in Preferences). The number of threads can be selected as auto,1,2,3,...,16). auto corresponds to previous versions that sets it to the number of processor cores Windows reports (typically the most efficient choice) If no direct sound then the Show3D: line  S->R with SxR spheres is dashed green and says "No direct". Applies also if no direct sound is included in special test options as discussed above. Map measures STI dialog change/addition: The ISO 3382:3 (Annex B) “Minimum Change in Task Performance” derived from STI has been implemented and the STI dialog now has a Show: list-box where either STI, CIS or MCiTP can be selected. MCiTP is also added to the selection of batch map exports and Statistics is enabled. Absolute Predict SxR impulse response displays with variable scales (LMB up/down). CATT-A: AUDABS and AUDABS1 - new indirect options to specify audience planes. Two new directives AUDABS and AUDABS1 that work the same way as ABS and ABS1 but when used in a plane definition they will indicate that the plane is an audience area mapping plane in the CAG-file exported for TUCT.  Optional TAB-delimited copy of results from Interactive RT estimation. When the Statistics or OK button is clicked the results can be selected as a readable text-file, as in previous versions, or copied as TAB-delimited text to the clipboard for pasting into a spreadsheet. A v9 installation can be updated or installed from scratch. For users with expired free updates (see Help | About)  TUCT maintenance updates were available (include all previous fixes): Previous maintenance fixes (v1.0h:5, v1.0g:4, v1.0f:6): (g,h) CATT-Edit Help menu attemped to load the old catt32.chm file.  the 3rd order B-format N and O has changed, for details on old versions < v1.1a see the bug-list. (h) The direct sound ("free field") for DLf and DL2 measures did not include air absorption. Of little practical consequence since according to ISO 3383-3 these measures are to be A-weighted and the direct sound distance are short. (f,g,h) The h-based Predict SxR LF was not predicted well for rather complex reasons but is fixed and v1.1 will also have an E version. LF is a very sensitive measure also for measurement, a good example is from the 3rd Round robin (PTB studio) where the measured value for one position varied between 8-35% at 125 Hz and 19-37% at 500 Hz depending on the measurement group. (h) The DLf and DL2 measures can sometimes use the wrong selected band. It occurs if the band is changed while viewing DL measures.  (h) STI female voice had an error in the beta functions that if it hit was obvious (the 125 Hz MTI value dropped to zero). It appears that female voice is used quite seldom especally since STI-Pa is only for male voice. Some minor additions Previous maintenace fixes (v1.0h:4, v1.0g:3, v1.0f:5 120410): The 1st order ISM in Predict SxR may in some types of rooms with many internal blocking walls or objects give false reflections. Some minor additions Previous maintenace fix (v1.0h:3 120223): Sequence processing and a small addition indicating each step-files' basic settings. Walker.exe update (full version), the exe first included in v9.0b:1 required an external DLL that was not included. Previous maintenace fix (v1.0h:2 111220): Masking for 4th edition STI
CATT-Acoustic v9.0b update including TUCT v1.0h	111202	A more responsive PC during calculations A Lambert 1D scattering function for walls with battens and 1D-diffusers A novel and flexible mapping implementation of the DLf and DL2 measures (ISO 14257) suggested for use also in open-plan offices (draft ISO 3382-3) that allows these measures to be used as design tools where the limitations and pitfalls also can be understood. Comprehensive application notes. T-30 statistics for selected source and receiver combinations, useful for understanding room properties a recline() function for placing receivers in a line (useful for DL2 and DLf) STI optionally according to IEC 60268-16 4th edition (2011) Sequence (batch) processing now also in TUCT Export (to spreadsheet) of a selected set of maps from Audience mapping Creation and export of ITU 5-channel impulse responses now also in TUCT, many options ranging from actual mic setups (INA5, OCT, MMA etc.) reflection by reflection to three ways as a post-process from B-format using the patented BPhormer™ process, the Sector mic™ and basic coincident patterns Export of various mono mic impulse responses (omni, cardioid, supercard, hypercard, fig-of-8)  Graphics copy/save/print options also with minor dialog graphics such as map statistics Predict SxR algorithm selection tips on the settings dialog  Time Trace "fast forward" skipping over time segments of little interest Loudspeaker sensitivity variables that can be used in the source file Optional auto-viewing of saved PL9-files in TUCT (useful for saving temporary results for later viewing/export or comparisons) MultiVolver WCP addition for faster selection of multi- channel WAV input.
CATT-Acoustic v9 printed manual shipped The manual includes the main CATT-A and TUCT manuals in one binder	110928	The printed v9 manual has now been shipped to all users that had unexpired free updates July 5 at v9 release. .
Fix for CATT-Edit under Win 7	110914	Some earlier versions (before Win 7) misinterprets the Windows version and puts a limit to the size of files that can be loaded. Free for all licenses, run the installer (since Vista it can be hard to simply copy a file to the Programs folder).
The Common Loudspeaker File format CLF2 v2 update released	110909	CLF2 v2 introduces phase and optional filters for beam-steering and/or cross-overs and multiple files are used to describe an array or a multi-way loudspeaker.  As CLF2 v2 files appear CATT software will support the new options.  To update your viewer and see CLF2 v2 sample files go to  www.clfgroup.org
Fix for DXF2GEO v1.0f (in v9)	110830	DXF2GEO has required very few updates after release so with the recompilation to get v9 icon colors it was forgotten that meanwhile a change had occured in the 3D libraries. Typical symptoms a crash when "Show both sides" and that the display would have triangles when there should be 4-corner FACEs. This affects the display only, not the export to GEO. A fixed version can be downloaded replace the one in your CATT folder.
CATT-Acoustic v9 release including TUCT v1.0g	110705	CATT-Acoustic v9: The Prediction module is renamed to Modeling module and all prediction and auralization except Interactive RT estimation are removed, further prediction/auralization now only in TUCT™.  v8 PRD-files can be loaded but will be saved as MD9, the new basic modeling project settings file format for v9. New PL9 graphics for geometry view/check The PL9Viewer module is almost identical in terms of menus to the old Viewer module but is totally new (based on the standalone PL9Viewer and TUCT™ graphics libraries) The Directivity module is identical but creates new PL9 graphics with some changes, especially to the polar diagrams. Update ActiveAudio DLL adding the Ray-On 100 array model The Surface properties module is identical. The Post-processing module is removed, what remains of interest is now under a new Modeling:Extras menu. the Sequence processing module is removed. the Source addition module is removed. new Introduction Manual (Help menu). New CATT-A + TUCT™ pdf manuals New  CATT-A + TUCT™  printed manuals both in one binder - will be sent out in September. Includes the 4th major update of CATT TUCT™: Map measures results have a new Type Echograms were an echogram is shown for each map point when the mouse is moved over the map.  In Window | Image Source Model the left Ctrl is held when selecting Show all paths only the wall hits will be shown. A new help/manual section indicates hidden features such as the one above when holding Ctrl (see 4.2 Hidden options) Update was announced over the mailing-list and if missed contact CATT.
TUCT v1.0f:3 maintenance update	110705	Previous maintenance update of TUCT v1.0f that fixes issues below: Fixed in v1.0f:2 110325: use of a source roll angle would sometimes give the wrong rotation, the maintenance also includes catt32.exe v8.0k build 2.02 since the roll problem was also due to the CAG-file export. the mean free path would be the estimated slightly too short if the model e.g. was very flat, affected T-Sabine and T-Eyring but no other predictions some small fixes
TUCT v1.0e:5 maintenance update	110705	Previous maintenance update of TUCT v1.0e that fixes issues below: Minor fixes in v1.0e:5 110705 Fixed in v1.0e:4 110325: See v1.0f:2 fix above Fixed in v1.0e:3 110204: dBA and NC update also when manual entering of noise in U50 and STI dialogs improved Meta export Misc. minor interface fixes Fixed in v1.0e:2 101210: Map measures and Map direct could randomly give strange results but only on some PCs. Symptoms could vary but a common denominator was that the results were clearly unrealistic. The reason was the intricacies of multi-threaded parallel processing that behaved differently on different PCs.  Update was announced over the mailing-list and if missed contact CATT.
TUCT v1.0d:6 maintenance update	110705	Previous maintenance update of TUCT v1.0d that fixes issues below: Minor fixes in v1.0d:6 110705. This is the last maintanece of v1.0d Fixed in v1.0d:5 110325: See v1.0f:2 fix above Fixed in v1.0d:4 110204: dBA and NC update also when manual noise entering in U50 and STI dialogs improved Meta export Misc. minor interface fixes Fixed in v1.0d:3 101210: See v1.0e:2 fix above Fixed in v1.0d:2 101029: Map measures with interference on could give wrong results in some cases. It appears that the differences were not easy to spot but took a special synthetic case for it to be clearly seen. the hidden option to allo use of all reporetd cores did not work as documented especially not with hyperthreading. Some v1.0e additions added to v1.0d:2 : all models are rotated around their centers (as in 3D-viewer and CATT-Acoustic PLT) instead of the origin. due to diffuse reflection being handled by a stochastic process two runs with the same room and the same prediction settings will always give slightly different results but from this version the Map measures algorithm has been improved to lower the variation. Fixed in v1.0d release 100921: Further fixes not likely to have affected except in special cases and was never seen in normal rooms but only in a stadium case, the syptom was that the pressure-based direct sound looked like it became much too strong. Fixed in v1.0c release 100819: Since release of TUCT there have been a handful of cases reported where these algorithm options have created strange results. The symptoms have been that some reflections became clearly too strong but it has been difficult to find the reason for this since it was only obvious in some special cases and almost only if really many rays were used. However, a case was finally reported where it was possible to simplify the model with the problem still remaining so it could be investigated and fixed. Update was announced over the mailing-list.
Update of the ActiveAudio StepArray DDI module SA400P and SA180S added	101008	The SA400P and SA180S models are added. It will be included in subsequent CATT-Acoustic update but can be downloaded in advance (requires unexpired free updates). UnCTT and UnZIP the contents in your current "CATTDATA"\Sd2Data\ActiveAudio_CATT folder overwriting old files.
Update of the Nexo GEO DDI module Geo S12 added	101007	The Geo S12 model is added. This DLL will be included in subsequent CATT-Acoustic updates but can be downloaded in advance (requires unexpired free updates). UnCTT and UnZIP the contents in your current "CATTDATA"\Sd2Data\NexoGEO_CATT folder overwriting old files.
Update of Nexo SD1-format directivity files	101007	Download and unzip to your "CATTDATA"\SD folder or a sub-folder.
B-format microphones	100921	A list of available B-format microphones can be found here. If there are any further mics to include please send an e-mail.
New DDI module for Tannoy QFlex DSP-steered arrays	100819	A new DLL Directivity Interface (DDI) module for Tannoy QFlex array and is included in subsequent CATT-Acoustic updates. This DLL does not allow for entering the steering parameters directly but relies on data generated by the QFlex BeamEngine™ software. Tannoy_CATT.CTT  (2,876 kB) Requires unexires feee updates. Run UnCTT and UnZIP the results in a folder "CATTDATA"\Sd2Data\Tannoy_CATT
v8.0j build 2 is released Including the first update of CATT TUCT™	100629	The first major update of the new CATT TUCT™ software includes a range of useful additions: Saving/loading named 3D views, global or project specific Shortcut to load a new project using the same 3D-view as the current Project-based automatic saving of the latest used settings for Predict SxR, Map direct and Map measures Simpler scrolling through Predict SxR results Different internal Predict SxR algorithms are used depending on case, no more memory issues with many receivers and/or long echogram/IRs An additional normalized Schroeder plot showing the decay for one band against a backdrop of all bands An interactive option to show only the energy echogram response An STI limit can be specified for STI maps indicating which positions are below the limit Optionally suspend update of a big map while changing Max/Range Map spreadsheet export with automatic separation into layers that cover eachother in z (such as a balcony above a floor audience) Seperate map z-layer displays (show balcony by itself, floor by itself or both) Time trace includes diffuse reflection as well (it was initially not included since it often creates a too confusing display but has its uses) Several small useful additions and changes
Many new HRTF sets	091217	After considerable processing all the LISTEN project HRTFs have been converted to CATT-format (requires v8.0i:2 due to a new angular resolution). Because of the big total size (102 sets, 74.5 MB) these HRTF libraries are not included in installations or updates but can only be downloaded.
More anechoic recordings	090925	The Dipartimento di Ingegneria Università di Ferrara, Italy have made available a set of anechoic recordings of islamic songs, byzantine songs from CAHRISMA project and a set of anechoic ancient greek songs and music from the ERATO project. Non-commercial use only.
Multiple CPU core processing clarification	090406	v8.0h and above will benefit from multipe cores if the cores are all on the same chip. The most common useful hardware would be a quad core while a dual quad core (i.e. 2 x 4 cores) actually may run slower than a single quad core (will be addressed in the next release so that it will run at the speed of a single quad core). To benefit form multiple cores on different chips requires a much more complicated programming and is not planned.
More anechoic recordings	090110	The Helsinki university has made new anechoic recordings publicly available.
GratisVolver™	081001	update v1.4a with 4-channel convolution (typically B-format IRs).
A list of some available measurement software	080402	As a service to users, a list of some available room acoustics measurement software has been assembled.
GratisVolver™	080321	update v1.3c with enhanced IR viewing and graph copy.
CLF Software update	071212	New display options for balloon and polar viewing, and more.
New printed and PDF manual	070918	A new printed manual has been created covering all additions including v8.0g:2. New purchases or updates include the new manual and all with unexpired free updates will receive the new manual by mail during September..
GratisWavPlayer™	070705	update v1.0b loop options added.
The FIReverb Suite 4th Ed. update.	070518	Included with full v8.0g version and later updates
3rd party software and tools	070228	SketchUp plugins, MATLAB utilities
Links to anechoic music	060120	New CDs, CDs out of print and internet links.
Fogg Art Museum Lecture Room links to paper and models for download	050906	"A calibrated recreation of the birthplace of Room Acoustics" A Forum Acusticum Budapest 2005 paper with predictions and auralizations of this famous auditorium.
Surface properties library from RPG Diffusor systems	050420	A range of  surface propertis from RPG diffusors and other acoustic materials.
The Common Loudspeaker File format (a.k.a. the CLF) is released!	050415	The CLF has been released. For a background to the CLF, and download of a free viewer with sample files, go to the CLF web page: http://www.clfgroup.org. For CATT-related CLF-info go here.
GratisVolver™ Free software	050317	A convolver for mono or stereo WAV-file impulse responses (IRs). WAV-file playing (individual playing of input file, IR and processed file). A self- contained small software specially made to encourage viewing and listening to IRs and convolving with anechoic/dry music. If placed in the CATT-folder it will be on the File|External CATT Tool menu (from v8.0e) .
Epidaure GEO converter	030807	A first beta version of Epi2Geo has been completed.
Can CATT-Acoustic handle coupled rooms? FAQ19	020816	In what cases the various prediction methods employed  can be expected to work well, and a note about a new  RTC variant under development for coupled rooms.
EXP2SD1 converter update	020322	EASE v2 text EXPort-file loudspeaker data converter. Can now convert files both for v7 and v8.
EAS2GEO geometry converter	020228	EASE v3 geometry export conversion to CATT GEO/LOC.
Instrument directivities available from PTB, Germany	011009	PTB have made available 13 different directivity  files in CATT SD1-format for orchestral instruments plus singing voice.
Surface properties from PTB	011009	PTB have made available many materials in Excel format.
More info on diffusion (scattering) coefficients	010915	Recent activities with ISO and AES has resulted in some available data and a measurement procedure for diffusers. FAQ 3 is expanded.
Absorption data	000323	7 import libraries (163 materials)

Read this!

If CTT-file extraction fails it may be because:

• the time for free updates has expired.
• the installed license does not permit extraction. An example: HRTFs and headphone filters cannot be extracted if a prediction-only version is installed.
• UnCTT needs updating (some data e.g. Surface properties, loudspeaker data, sample models etc., will be continuously available independent of if free updates have expired). If you can't extract free files with UnCTT click here.

Updates

Main application (CATT-Acoustic)

• it is the free updaes date given rather than the current date that determines if your license permits a free update. If your key expires e.g. (yymmdd) 150710 you are entitled to an update dated anything <= 150710 even if the current date is > 150710.
• a major update file requires a previous installation but contains all new and changed files since v9.0. Users that still only have v8 will when updating receive a complete new v9 installation with instructions what library data needs to be copied form the old v8 installation (would mainly be the surface properties library and source directivity files created).
• when clicking a CTT-file some browsers, or even some versions of the same browser, instead of downloading the file assumes it is a text-file and displays a lot of garbage text. If so, instead use right mouse button download (Save Link As, Save target as etc. depending on browser)
  

Update cost and options

• The update cost is normally given in the License agreement for a 12 month period.
• If not specified in the license agreement, a 6-month period costs 15% of the full price (older licenses) and 12 months costs 20%. 
• Update periods do not have to be contiguous.
• After an ordered update:
• a new key is sent by e-mail
  
• if needed, a new installation can be downloaded
  
• (if applicable) updated printed manuals will be mailed
  

The FIReverb Suite (full license)

The Suite has its own support page: www.catt.se/suite_support.htm

Important note: The Suite is considered an upgrade and to have it run in full mode, your full-version CATT-Acoustic key must not have expired. You can still install and see how it looks but it won't do anything really useful. As soon as an updated key is installed it will run in full mode, contact CATT or your distributor for an upgrade.

A comprehensive audio demonstration/tutorial with stereo  5-channel upmix and other examples is available.

Update problems?

Note that if you can't update it is typically because your free updates have expired or that the wrong license was selected and not because of UnCTT problems (See CATT-A Help | About or the UnCTT dialog regarding when your free updates expire). However, due to several internal license mechnism changes and the change to use of a .DAT license key-file, a too old UnCTT may no longer work, or it may create a corrupt file after extraction. If you do not have an UnCTT at least v1.0k send an e-mail to CATT   and you will receive a link to a new version (due to security reasons UnCTT is not available for direct download).

Installs (for users with unexpired free updates)

Important: for future installations back up your installation-file along with the license-file.

Concept Halls (all licenses at any time)

Types that can be interesting to create one or more generic models for are:

• Concert hall
• Chamber music hall
• Underground station
• Train station
• Sports hall
• Operas
• Church
• Chapel
• Factory
• Control room
• Studio
• Listening room
• Classroom
• Auditorium
• Outdoor arena
• Stadium

	Underground station #1 This model consists of a generic Underground station designed so that the following parameters can be varied: length, width, height, trains:on/off, ceiling:flat/arched, ceiling arch type,entrance:size/location, platform width, train size, track width, upper/lower wall properties etc. This model is simple enough not to warrant any other documentation than the GEO-file itself.
	Factory #1 This model consists of a generic  factory designed so that the following parameters can be varied: length, width, height, wall angles and upper/lower wall properties. Sizeable and moveable box objects that can mimic machinery can be moved around with sound sources automatically following. This model is simple enough not to warrant any other documentation than the GEO-files themself but is not a good model for real calculations since the floor under each "machine" is not removed (it was made so students easily could move them around). Note: this model was made mid 90ies for university students use to in an exercize be able to study basic factory acoustics without having to waste time on the modeling itself. Since then the care about model correctness, associtated with increasing algorithm sophistication, has increased and the way the objetcs are modeled here is not how it should be for a real project: .
	Listening room #1 This model consists of a generic home theater designed so that the following parameters can be varied: length, width, height, soffit size, corner construction, upper/middle/lower wall properties, easy sound source placement for various kinds of surround. Contains PDF-file documentation.

Surface properties (all licenses at any time)

Note: with new v9 purchases the TXT-files below are already installed in the "CATTDATA"\ABSLIBS and a library containing all properties have been created (ABSLIB_full.DAT, to use it just select it in Preferences).

Notes:

• Unfortunatelly there is a quite old text-file import bug (been there since early 1999 but apparently no one has used the import function...). The latest updates have the bug fixed but older versions will refuse to import materials without diffusion. To upgrade to the latest version is always recommened but for older versions a trick can be used for the import:
• All import text-files given here (except the RPG library) ) have a commented-out "zig-zag" diffusion ;L <10 90 10 90 10 90> that can be enabled in an editor before import. Since the zig-zag pattern is very easy to spot while browsing through imported materials it is easy to switch off the diffusion for those materials (such materials would typically only have default diffusion).
• Scattering coeffcients have been added where appropriate, e.g. for audiences or chairs. Note also that scattering can be added to a library material using the ABS stament like e.g. in: ABS newprop = oldprop L <5 7 8 12 14 16>  where oldprop is already defined in the library.
• Values > 100% are set to 99%. Values > 100% is an artefact of the measuremet method used and can't be used in prediction.
• All data is provided "as is" and it is strongly recommended that the reference works, if possible, are purchased and used as guidelines for the application of the data. The data here can only serve as initial estimates.
• Many material descriptions are in the original references very short or cryptic and it is sometimes not indicated e.g. what is behind (backing) a material or construction. In practice, values can vary widely between materials with seemingly similar descriptions.
• Translations are sometimes tricky (e.g. from Petersen and Karlen references) and may give unclear or incorrect descriptions.
• If several similar materials are given in the references they are named e.g. PLASTER10, PLASTER11, PLASTER30 etc. The variation of values is also useful information.
• Some materials included in the references have simply been left out because lack of a clear enough description (in many cases the value are given as typical values rather than for a specific detailed case).

Architectural/Room Acoustics text-book references

Directivity data (all licenses at any time unless a DDI update is required for SD2-files)

[Instruments] [Human voices]
[SD1 loudspeakers (validated)] [SD1 loudspeakers ("as is")]
[DDI (DLL Directivity Interface) modules]
[The Common Loudspeaker File Format (CLF)]
[The Common Instrument File Format (CIF)]

Instrument directivities (SD0 or SD1)

Human voice directivities (SD0 or SD1), also see CIF for higher resolution data

SD1 directivities supplied and validated by respective manufacturer

*) The data below is converted for v7 and does not contain the 8kHz balloon even it was present in the original data. v8 and higher will extrapolate from 2k and 4k.

SD1 directivities supplied by respective manufacturer but not yet validated, provided "as is"

SD1 directivities supplied by CATT-Acoustic users with access to EASE v2 data, provided "as is"

SD2: DLL Directivity Interface (DDI)

The Common Loudspeaker File Format (CLF)

The Common Loudspeaker File Format (CLF) was announced Oct 22 2004 and released Apr 15 2005.
For a background to the CLF, and download of a free viewer with sample files, go to the CLF web page: http://www.clfgroup.org.

CATT-Acoustic supports the CLF format from v8.0d by direct reading and use of the distribution binaries (.CF1 and .CF2).

The Common Instrument File Format (CIF)

The Common Instrument File Format (CIF) was released Oct 30 2020.
For a background to the CIF, and download of a free viewer with sample files, go to the CLF web page: http://www.clfgroup.org.

CATT-Acoustic supports the CIF format from v9.1f by direct reading and use of the distribution binaries (.CI1 and .CI2)

HRTF libraries (full license at any time)

Additional libraries

HRTF and headphone eq format specs (v9: full license, v8:full Huron license)

    hrtfinfo_v7.CTT (28kB)

Note: the HRTF v7 format for can be used also with v8 and v9.
Note: from v8.0c HRTFs with arbitrary resolution can be used but the conversion cannot be done in CATT-A since each library will be unique, contact CATT for details.

Headphone filters (full license at any time)

Be ware that no filter can perfectly compensate for a headphone since the transfer function may vary considerably:

1. between headphones of the same type (due to manufacturing/wear)
2. between different persons wearing the same headphone (different coupling to the head/ear)
3. between replacements of the same headphone on the same person (different coupling to the head/ear)

A headphone's suitability for binaural replay has very little to do with how suitable it is for normal stereo listening since the goals are completely different. For example, most stereo headphone designs attempt to suppress the ear canal resonance at 3-4 kHz with a -3 to -30 dB notch with various Q-values depending on brand/type, while for binaural listening, based on HRTFs measured with microphones at the entrance of the blocked ear canal, the headphone should ideally have a flat response (as measured at the same microphone point). The headphone filters attempts to create a reasonably flat response.

Note: the headphone eq format for v9 remains the same as for v8 and v7.

Anechoically recorded (or dry) music and speech

File converters (all licenses at any time)

Note: from v8.0e, if put in the CATT folder these converters can after a restart be loaded via File | External CATT Tool.

DXF converter

EASE v3 (and v4) geometry export to CATT GEO/LOC-file converter

  EAS2GEO_EXE.CTT  (020228, 46 kB)
  EAS2GEO_HLP.CTT   (020228, 16 kB)

However, there are some important differences in how the geometry is built and that must be considered (also documented in the included helpfile):

1. audience areas are in EASE modeled as floating single-sided planes above the audience and the audience itself is modeled on the floor. These audience planes have no consistent normal direction, but the importer forces it to be upwards. The planes must be converted to a boxed-in audience after import, modeling the audience on the floor will not give good results and floating audience planes should not be used. For reference, the floating audience planes are converted to a separate included GEO-file that can be switched off or modified.
2. sub-divided surfaces, say a window in a wall, apparently called "coated surfaces" in EASE, are in EASE modeled by placing the window surface some mm in front of the wall and must be put back into the wall (e.g. using lock()) and converted to sub-divisions after import.
3. double-sided planes like reflectors are only exported as a single plane and the other side with opposite normal has to be created after import.
4. 1-3 will show up as single-connected corners in the debug file
5. models seen so far have been quite inaccurate but it is not yet clear if that has been modeling errors or inherent EASE problems. The export uses an inconsistent number of decimals (from 1 to 6 without apparent logic) so some of the inaccuracy may come from the export itself. It is strongly recommended to create a geometry debug file after import, checking plane normals also seem to be a good idea.
6. keep in mind that if you are involved in a project where EASE have been used, and you want to import the model to save some modeling time, that many times the EASE model has been created only to check the sound system and the direct sound coverage and it may not be very well suited for room acoustics prediction.

EASE v2 loudspeaker export-file (.EXP) to CATT-SD1 import text-file converter

  EXP2SD1_EXE.CTT (CTT refreshed 201207, 071018, 54 kB, this version also works with the Xtra32.DAT license file used from CATT-Acoustic v8.0g)

EXP2SD1 converts to the CATT-SD1 text import format (v7 or v8).  If a user succesfully has converted models in an EXP-file to CATT format they can be sent to CATT and will be provided "as is" to other users.

Odeon file converter

  Ode2Geo_EXE.CTT (39kB)
  Ode2Geo_HLP.CTT (23kB)

Note: these have not yet been converted to work with the Xtra32.DAT license file used from CATT-Acoustic v8.0g or later. It can be fixed if needed but the old Odeon format is of little interst now. Later version of Odeon can export to GEO format (some work remains after conversion but in principle it works).

Epidaure file converter

A first beta version of Epi2Geo has been completed (030807). This is a converter from the room model GEO format used by the French prediction software Epidaure to CATT-Acoustic GEO.
Please e-mail any Epidaure GEO- and corresponding material library MAT-files you may have so that  the converter can be further tested before release.

3rd party utilities

• Skp2Geo by Euphonia, France -  details
• SU²CATT by Akustikbüro K5 GmbH, Germany  - details
  

• m-file scripts that can read the CATT geometry export .CAD format into MATLAB, download EDBreadCAD (25-OCT-2006, 11 kB).
  Primary use of this script has been with the "EDToolbox" which uses CAD-files as geometry inputs and computes impulse responses with specular reflections and edge diffraction, for details see http://www.iet.ntnu.no/~svensson

Tips and tricks

T1. Studying reflector coverage

v8,v9: use the new Geometry view/check REFLINFO.PLT /.PL9 where reflector edge contours are shown without any calculation required.

T2. Mapping only the direct sound

v8.0a-d: has a short-cut button that selects direct-sound only functions. Use also the new Geometry view/check SRCINFO3D.PLT where -3 dB directivity contours are shown without any calculation required.

>= v8.0e and v9 TUCT: have separate direct sound mapping.

Frequently Asked Questions

Q22. Misc. unusual v9 issues that are easily fixed

Q23. The OpenGL 3DViewer or Walker does not start

Q1. Why does the reverberation time become longer than the one estimated by Sabine and Eyring (SabT, EyrT)?

1. No scattering coefficients have been applied or diffuse reflection is switched off (General settings). If a hall does not act as "geometrically mixing" due to its shape and if the absorption distribution is uneven, the RT is very dependent on the settings for scattering. Typcially no surface should have less than 10% scattering (use Default diffusion in General settings) unless very big and smooth that may have 5%, and surfaces that have some roughness higher values (see Q3 below). For reflectors, tables etc. Edge scattering can be used. Note that Sabine and Eyring values actually assume that all surfaces are 100% diffusing and that all surfaces are visible from any surface. A useful paper can be found here: http://www.catt.se/ASA-Balitmore-2010-CATT.ppt. A useful informative test is to in TUCT2 also predict with 100% scattering and 0% scattering (a File | Save Modified CAG As option). If 100% scattering does give Sabine or Eyring it is very unusual geometry or there are severe geometry errors. If with 0% T30 become much longer than with 100% it is a case where scattering has to be extra well considered. 
2. The geometry may have been modeled so that the volume (V) and/or the surface area (S) is not correctly estimated and V and S affects the Sabine and Eyring values (see v8 manual 2. Prediction module/Modeling notes or v9 manual 2. Modeling module/Modeling notes). In such cases the two estimates of average absorption factor (AbsF and AbsFg seen e.g. in the right graph in RT_ss.PLT in v8) will often differ significantly.
3. If, with reasonable scattering coefficient values and accurate absorption data, the RT still is longer than Sabine/Eyring the room is highly likely non-diffuse and give s a double-sloped decay also in reality and a flutter echo. As above good "engineering check" is to calculate both with no scattering or 100% scattering and to see how much the RT differs. If it does not differ a lot the room behaves nicely statistically and the predictions will be more accurate. TUCT2 has, for test purposes, a File option to save a new CAG-file with modified scattering. It can't be stressed enough that it is not sufficient to just look at the T-30 numbers but also the echograms and decays (Schröder curve) to see why values T-30 values became what they became and if it is a suffcient prediction. Similarly, it is important to listen to the IR and that also works in the basic license without full auralization.
4. All in all, it is crucial to "get to know the room" acoustically. e.g. if a too long T-30 is because of a non-diffuse room and flutter echo the acoustc treatment is differnt to when there simply is to little absorption. As time has past and these type of software are used more and more this important aspect seems to have become forgotten. 

There are several possible causes to lost rays, some are ntaural and some are the results of modeling mistakes.

1. The source may have been placed directly in (or even outside a wall) making half (or all) of the rays escape.
2. The model has holes (use PLINFO.PLT/.PL9 or COLORED.PLT/.PL9 geometry plots to check, don't forget to view the model from below). Even fairly small holes can cause a lot of rays to eventually escape.
3. The model has reversed planes (use PLINFO.PLT/.PL9 or COLORED.PLT/.PL9 or the OpenGL 3D-viewer geometry plots to check).
4. Some planes are very inaccuratelly modeled (i.e. some corners are far out of the plane as described by a plane equation calculated from three of its corners). The debug file will list such planes (Geometry view/check).
5. If the predefined artificial absorption TOTABS has been used a lot, rays will not be lost but rather absorbed and it may lead to an open room conditions since very few rays will remain bouncing around. Rather use a <99 99 99 99 99 99> absorption (or more physically correct lower at low frequencies) than TOTABS. "Black and white modeling" i.e. either totally reflective or absorbing surfaces may be useful sometimes to exaggerate problems and tendencies in a room shape but it does not sit well with getting good numerical results and absolutelly not for auralization.
6. See Q8 for more details on how intended holes can be handled

AES and ISO have had working-groups on the subject for many years aiming to measure scattering coefficients and diffusion factors. It is a complex subject but some useful data for computer modeling is now coming out of it. Two types of coefficients have been defined:

Diffusion coefficient (d): is a measure of the uniformity of the scattered sound. The purpose of this coefficient is to enable comparisons between diffusers at the design stage. For a detailed definition and measurement procedure see the standard document (AES-4id-2001, JAES 49(3), 149-165, 2001). This coefficient is not to be used in CATT-Acoustic (even if this is the name used in v7 that preceded the ISO/AES work).

Scattering coefficient (s): is a measure of the total amount of scattered sound - for random incidence - in relation to specular sound. The purpose of this coefficient is for use within CP software such as discussed in these papers. Fore a detailed definition and measurement procedure see (ISO/CD 17497:2000, "Acoustics - Measurement of the random-incidence scattering coefficient of surfaces"). This coefficient can be used in CATT-Acoustic. Note however some similar software have a very different modeling of scattering so the same values can the no be used. 

For an overview of both coefficients and how they relate to eachother see:

• "Scattering in Room Acoustics and the Related Activities in ISO and AES," J. H. Rindel, 17th ICA Rome 2001, paper 6KN1.02
• "Contrasting surface diffusion and scattering coefficients", T. Cox, P. D'Antonio, 17th ICA Rome 2001, paper 6B.09.01.

However, for most walls and objects no measured data will be found and the basic guidelines below can be used (but all rooms are unique and require morde detailed considerations) :

• 40..70% for 125..4k for audience areas
• for rough surfaces set high values (80%) where the roughness is on the order of or higher than the wavelength, and gradually lower below. E.g. if the roughness scale is 3 dm, set 80% for >= 1kHz, 60% at 500 Hz, 30% at 250 Hz and 15% at 125Hz.
• use Auto edge scattering on flat hard objects like desks in classrooms, cupboards, windows , reflectors etc.
• use Auto edge scattering also on patches of materials that can create impedance mismatches. For example, a carpet patch on a concrete floor will create diffuse reflection even if it is almost exactly in the same plane as the floor. Wenever a sound wave "feels" an impedance change there will be scattering.
• typically 10-20% minimum on all surfaces (10% on big flat ones, 5% on very big flat ones). The exact amount depends on if it is a flat surface in reality or if it is just modeled as flat surfaces omitting surface details (as it typically should be within GA).
• except for actually flat surfaces the surface scattering (as set in an ABS GEO-file statement) is inherently frequency dependent, think about wavelengths vs omitted surface details..
  

1. estimate the existing absorption as well as possible, avoid TOTABS, use 99% instead.
2. set the scattering of any audience areas like above.
   
3. use Auto edge scattering on all small objects with free edges or where there is impedance mismatches, not however that using Auto-edge will not help if a surface is too small for GA.
4. assign surface scattering as above on actually uneven/rough surfaces
5. fintetune the remaining overall surface scattering starting from the recommended values above, to match the measured T-30. In most rooms, if all the other steps are done this should typically not need much adjustment.
6. if the predicted T-30 still differs significantly from the measured T-30 it is likely that a) something significant has been missed, b) the measurement is not good (low frequency noise problems are common)  or c) that the room has estimation problems due to extreme shape and /or absorption distribution. Please send the files for feedback in cases like that, see Support.
   

Q4. Why does the <= v7.1 convolver sometimes fail to read a WAV-file that I have created myself (full versions)?

Removed, concerned only v7.

Q5. Why can't I always select samplerate in the Crosstalk cancelling dialog (full versions)?

If Normal operation is selected then the samplerate is determined by the SIM-files to be filtered. It is only when Create X-talk filter only is selected that the samplerate can be set (should then correspond to the binaural WAV-files to be filtered, 44100 or 48000 Hz).

Q6. How can I do e.g. an STI color map over standing listeners like in a train station?

This is an example of a situation that cannot be simulated as straight forward as a seated audience but it can be done in a quite satisfactory manner using the steps below.

1. First select the floor as "audience plane".
 
2. Set a map at ear height (1.7 m or so), ignore the warning that map height should be = half a map step since it applies only to a seated audience (so that rays cannot travel under the receivers without being detected).
 
3. Assume that the absorption area (in m² Sabine) of a standing person is Ap, that there are Np persons on the floor, that the empty floor absorption is alpha_empty and that  the floor area is Sf.
 
4. Calculate a new floor absorption "with people" like this: alpha_new = (alpha_empty*Sf + Np*Ap)/Sf.
 
5. Increase the scattering on the floor to indicate that it is occupied by people is scattering the sound.
 
6. For some refinement the area below each person could be removed making a slightly different formula but it is likely not to be necessary since the floor is typically very hard in cases like this and the absorption from the people will dominate.

Normally, for rooms such as auditoria with just a few hard surfaces ABS concrete = <1 2 2 3 3 4> or similar works fine (values depend on if the concrete is painted or not etc.). To change to <2 4 4 6 6 8> will not change the RT dramatically since the concrete absorption still is small as compared to the audience absorption. However for a very hard room, such as an empty reverberation chamber or a totally untreated room with concrete surfaces, making the change above will half the RT since it is directly dependent on the values for concrete and decimals in the absorption percentage starts to count! This has nothing to do with the prediction method used but is just how it works. There may be other similar cases where e.g. a church may be built mostly of brick walls and the values for brick will directly control the RT for the empty case (and brick is one of the worst materials to know the absorption for since it depends on the stone porosity, the mortar and if the mortar is flush with the stone or not etc.).

Q8. How can models with deliberate holes be handled?

Deliberate holes in a model (e.g. an open side in a train-station or an open window) can be handled in several ways depending on the situation.

CATT-Acoustic v8.0 Full detailed:

1. To have an actual hole (by not modeling surfaces at all or by switching planes off in General settings): recommended when the holes are a big fraction of the total area; this will indicate a number of rays lost. A lot of rays should be used in this case (calculations are faster with an open case then with a close case).
2. To model the holes by surfaces with the pre-defined absorption TOTABS, an alternative if the open area is relativelly small; this will not indicate lost rays but rather absorbed rays and will not issue a warning. This option will allow Interactive RT estimate calculation (a Sabine RT is reasonable if the openings are small).
3. To model the holes by surfaces with very high absorption <99 99 99 99 99 99>, an alternative if the open area is small; the advantage is that more rays will remain bouncing around giving better statistics as compared to 2) and will also allow Interactive RT Estimate.

No, typically not. If a source is placed exactly in a wall about half of the rays will directly escape towards outer space indicating a big loss of rays. If a receiver is placed directly inside an audience surface about half the rays will go undetected (even the direct sound) since it will depend on the least bit of accuracy that will flip between 0 and 1.

Q10. Can I model the audience as a floating plane without sides?

No, normally not since it will only give a correct estimate for direct sound and maybe first order reflections. Always model the audience as a box with sides (at about 1.2 m height and place the receivers slightly above - at ear height). A floating plane audience is sufficient only for direct sound mapping but reverberation time and most parameteres relying on the late part will be wrong. Unfortunatelly, the tutorial for v7.0 and earlier manuals show ed a floating audience to make it simpler and not everyone notices the comment that a box should be made for any real rooms. v7.2 and v8, v9 manuals show an audience box.

Q11. Why is the geometrical volume calculation sometimes inconsistent?

Removed, concerned only v7.

Q12. Will the CATT AutoLISP interface work with AutoCAD 2000 or higher?

Yes, from what has been seen so far it will. One thing that has been discovered is if a CAD-file (exported from CATT-Acoustic)  is imported via the interface, and the AutoCAD flags OSNAP and OTRACK are on, the imported drawing has errors. If this happens, set these flags off while importing and then back on again as required.

Q13. Which are the possible reasons for ray loss?

Assuming the model is supposed to be closed these are these likely reasons:

1. There are big plane inaccuracies (warped planes).

It is a necessary practise to generate a debug text-file every now and then (Geometry view/check) and check so that there are no significant INACCURATE PLANE CORNERS. If there are they should be fixed and using the lock() function is often the best solution if planes are not purely in x-y, y-z or x-z.


2. Some plane ids may have been used more than once (by mistake in OFFSETPL, MIRROR and/or object COPY directives), will only happen in very old versions.

Also this is given in the debug file (DUPLICATE PLANE  IDs) but immediate debug will trap it directly. This must absolutelly be corrected.


3. The source is placed exactly inside a wall, see also Q9.

Q15. How does surface (default and actual) and auto edge scattering relate to each other?

Assume that you have defined two abs materials in a GEO-file or in the Surface properties module as:

ABS noscatt = <...>
ABS scatt   = <...> L <...>

 

D	Default, Scattering option in General settings
S	Surface, Scattering option in General settings
S+E	Surface+Edge, Scattering option in General settings
d	surface default scattering values as selected in General settings
e	edge scattering (calculated based on surface size vs wavelength)
s	surface scttering (as in scatt above)

 

Resulting scattering for various setting combinations in General settings

Plane definition	Off	S on, D off	S+E on, D off	S on, D on	S+E on, D on
[ ... / ... / noscatt  ]	none	none	none	d	d
[ ... / ... / noscatt* ]	none	none	e	d	d+e
[ ... / ... / scatt  ]	none	s	s	s	s
[ ... / ... / scatt* ]	none	s	s+e	s	s+e

The reason for separating into e and s is that s is surface roughness dependant and e is size vs wavelength dependant (used to prevent strong specular reflections from surfaces small in relation to the wavelength). The resulting edge scattering is given below the surface scattering in PLINFO.PLT/.PL9 like e.g. in:

XXXX = <15 12 10  8  4  5> L < 5 10 15 20 25 30>
                           * <80 40 20 10  5  2>

or if no actual or default surface scattering is set:

XXXX = <15 12 10  8  4  5>
                           * <80 40 20 10  5  2>

Q16. Can I let clients view PLT-, PL9- or OGL-files using the stand-alone viewers? What files are required?
Both the CATT v8 PLT-viewer the v9 PL9Viewer and the OpenGL-based CATT 3D-viewer are free to send to clients for viewing result files. The files required are listed below and are easy to send as e-mail attachments. For convenience both viewers and required DLLs and help-files can be downloaded as a ZIP. 

CATT PL9Viewer for v9 PL9-files:

• PL9Viewer.EXE
• PL9Viewer.PDF (or .PDF for older v9)
• any PL9-files you wish to show
• if you have created a plot-file list text-file all filename paths either need to be edited to match the actual paths on the client PC or be given without path and placed in the same folder as the list-file.

• CATTOGL32.EXE
• Errors32.DLL (common error messages)
• OglSwitch32.DLL 
• CATTOGL32.CHM 
• OpenGL installed on the PC
• not a problem these days, all Windows version except the initial Windows 95 has OpenGL installed.
• any OGL-files you wish to show

CATT PLT-viewer for v8 PLT-files:

• CATTPLT32.EXE
• Errors32.DLL (common error messages)
• CATTPLT32.CHM 
• any PLT-files you wish to show
• if you have created a plot-file list text-file all filename paths need to be edited to match the actual paths on the client PC. From v8.0c Build 6 the PLT-files can simply be given without path and placed in the same folder as the lits-file.

Note: if graphics are printed, exported or copied without a CATT-Acoustic or FIReverb license, the text "DEMO VERSION" will be placed over the graphics. Screen viewing is the main purpose for non-licensed use.

Q17. Do I need to calibrate WAV (or SIM) files before WAV (or SIM) file addition (v8)

Short answer:

No, it is done automatically.

No, it is done automatically but calibrating them in advance will not create an error, it is just unnecessary. Remember that if a multiple source auralization is to be cretated for a PA system, where all sources have the same input sound, SIM-file addition can be made and the sum SIM-file can instead be convolved with the input anechoic sound. This is much faster than WAV-file addition. WAV-file addition must be used if the input sound to the sources to be added differs (say two persons talking or  stereo loudspeakers with the left channel in one and the right channel in the other).

Q18. How can I calibrate WAV-files that are created from separate WAV-file additions? (v8)
Assume there are several sum WAV-files each created from WAV-file addition and corresponding to the addition of several sources at several receiver positions, a complicated point is then to calibrate them relative eachother. If the software were to do that automatically there would be so many things to check that it would be very complex:

1. Normal compatibility (samplerate, receiver type, receiver id, head direction etc.)
2. Are all sum wav-files sums of the same sources? E.g. assume sum-file one is A0+A1+A2 and sum-file two is only A0+A1 then no calibration can be made.
3. Do all these sources have the same additional gains (as applied at addition, normally 0 but not always). E.g. assume sum-file one is (A0-10dB)+A1+A2 and sum-file two is A0+A1+A2 then no calibration can be made.
4. Do all these sources have the same additional delay (as applied at addition, normally 0 but not always). Example similar to 3).

CATT-Acoustic v7.2m, WAV-file addition info.

F:\WAVADD\SUM_AX_01.WAV is an addition of:

F:\WAVADD\TALKER1_A1_01.wav
   Gain      :    0.00 dB
   Aux Delay :    0.00 ms

F:\WAVADD\TALKER2_A2_01.wav
   Gain      :    0.00 dB
   Aux Delay :    0.00 ms

F:\WAVADD\TALKER3_A3_01.wav
   Gain      :    0.00 dB
   Aux Delay :    0.00 ms

Total file scalefactor  4.558E-01 = -6.83 dB to utilize full 16-bit range

This factor can be used to scale different WAV-file
additions assuming they have used the same individual
WAV Gain and are otherwise compatible.

A 4.558E-01
B 9.116E-01
C 2.279E-01

1. Find the lowest scale-factor (here 2.279E-01), this is for the file that had the strongest *actual* sound and had to be scaled least to get to be at max 16-bit (to avoid quantization noise until necessary)
2. Divide all the scalefactors with this number:

A 4.558E-01/2.279E-01 = 2.000
B 9.116E-01/2.279E-01 = 4.000
C 2.279E-01/2.279E-01 = 1.000 (this one need not be scaled)


3. Use Utilities | File scaling and scale all the sum WAV-files that got a factor > 1.0 in step 2), i.e.:

Scale (down) WAV-file A with a factor 2.000
Scale (down) WAV-file B with a factor 4.000


4. Listen to A, B and C and their relative levels will now be comparable.

Audience area mapping: can in principle handle coupled rooms unless diffraction effects can be considered important. However, many more rays need to be used as compare to normal rooms especially if the source is in one room and the map in another since only a fraction of the rays sent out will enter the other room so to get any reasonable sampling of the other rooms a lot of rays have to be sent out. Imagine throwing out a lot of tennis balls in room 1 connected to room 2 via a door and how few will bounce around in room 2. See also General note below.

Early part detailed ISM: not very suitable since many reflection orders are needed but may have some qualitative use.

Full detailed calculation: the RTC basically assumes that the prediction is made in a single room and not in severely coupled rooms (weakly coupled rooms seem to work well but the receivers should be placed in the same room as the source). The reason is that the RTC relies on a quadratic reflection growth for its tail correction and in coupled rooms the growth will vary with time (consider e.g. a source and a receiver in a small room connected to a large room; the early reflection density will then be that of the small room but the late density is more affected by the large room and no reliable reflection growth extrapolation can be made). It will also depend on the diffusion used how many rays enter in a second room and when they return. The RTC has a range of good properties, as has been shown by many successful measurement comparisons, but unfortunately regarding coupled rooms there has been very little measurement feedback so far so its performance is hard to evaluate. To address what seems to be a more common use in coupled rooms an RTC algorithm was ntroduced with v8.0b that does not need to use of the reflection growth and that will work as well as Audience area mapping for coupled rooms (but also here more rays than usual will have to be used). Possible positive side effects are better prediction and auralization of open rooms since they are also cases where the reflection growth function is unknown. See also General note below.

General: in addition to prediction-method related problems and diffraction, in coupled rooms the direct sound is often blocked and all early/late measures like D-50 etc. will be difficult to interpret since they in practise assume a direct sound to be present. 

Q20. Can I use a "tunnel horn" (also called a "boundary source") for prediction?

Some manufacturers offer sources that are named as above meant to be used for tunnels EVACs and placed (very) close to a hard smooth ceiling and where only the lower vertical balloon is given and instead the Sensitivity is increased by 6 dB under the asumption that reflection in the celing will act as pseudo direct sound and interfere perfectly. This may be useful in some old hand-calculation methods where only this pseudo-direct sound was taken into acount but when used in GA modeling also the sound radiated to the sides walls will have these 6dB added. In TUCT2 is used it will with the free-field version of the horn (ask the manufacturer in question for it) handle this ceiling reflection in itself (direct sound and 1st order specular interfere and will the result in these 6dB where it is valid) and will not have the problem of the too strong side reflections that have been mirrored in an often short lateral ceiling extension and where the ceiling image source reflection is not as close in time to the direct as are those along the tunnel and will therefore interfere in a way that will give less than 6dB. With v8 and TUCT1 the 1st order specular will not interfere so max 3dB wpould be added but considering many minor issues together is is often a very decent approximation. Note that if a half-space tunnel horn is used with an absorbing ceiling, or a ceiling with some structure such as beams, cables, ligthing etc., the 6dB added to the Sensitivity is highly questionable. An additional issue is that the proecedures used for interpolation in between the measured points assume a physcial directivity and can lead to odd effects for rays that come just above the given lobe (it can be seen in the Directivity module balloons). For exampel the CLF format was not made for these types of sources but for actual loudspeakers. 

Q21. How can I use a "CATTDATA" folder or room project files on a network?

Network paths have to be mapped to a drive letter (e.g. Z:) which can be done in Windows Explorer.

Q22. Misc. unusual v9 issues that are easily fixed

Missing library folder "CATTDATA"

When the software has been installed and when a new Windows user runs CATT-A the data library installer starts and the user can choose to have his own library or use an existing perhaps a common one for several colleagues. On some PCs (< 1%) this installer does not start (some Registry issue) and will have to run manually from the installation folder, depending on license the name is cattdemo_data.exe, cattpred_data.exe or cattfull_data.exe. In general "CATTDATA" can be selected or changed using CATT-A Help | Preferences. For more on this see CATT-A manual 1.1 Installation.

Symptoms: if directivity files or the Surface properties library have not been used it will not be noticed if the data library is missing until after a TUCT Predicted SxR when at the end of the prediction HRTFs and Headphone eq are needed and since it is an unexpected problem it will generate many error mesages of which only the latest one is seen "SxR Failed" / "Read SxR error". A public Hidden option (TUCT manual 4.2) will make all messages be logged on the screen but generally the only reason is a missning "CATTDATA" and when added check TUCT File | Preferences for settings on HRTFs and Headphone eq. Note that the prediction does not have to be remade, after the added "CATTDATA" simply use File | Load Old Results, and the same way the HRTFs and/or the Headphone eq can be changed after a prediction.

The TUCT screen controls become scrambled

A << 1% issue and for a reasonably recent v9.1 do this:

1. Close TUCT2

2. Hold down the Ctrl key and restart TUCT2

3. Select File | Preferences and check Restore windows at startup.

If that did not work it is likely TUCT1:

TUCT closes down with an ACCESS_VIOLATION message

Q23. The OpenGL 3DViewer or Walker does not start

Nov 8 2023: it appears that the driver has been fixed since a report from the user that first had the problem indicates that it now works again so it can be a good idea to update your driver (previously it didn't help to update the driver).

Some laptops, from ca. 2022, have a built-in soundcard Intel® Iris® Xe Graphics that has a problem with the OpenGL acceleration and it has affected many software. It may help updating the driver but not for certain. Some of these laptops also have an alternative NVidia graphics that instead can be selected in graphics or dedicated soundcard settings. Note that the OpenGL 3DViewer is not a necessary part of CATT-Acoustic and for the most part what it offers can also be found in CATT-A or TUCT that do not rely on OpenGL, it was created early 2000 when native graphics was too slow for viewing complex models. If it is really needed the OGL-file in question can be moved to another PC using another graphics card and displayed there.

Support

If some model gives geometrical or calculation-problems send the project files as e-mail attachments, in 99% of the cases this will save time as compared to just reporting a problem via a description.

Never send any result files  since it is takes too much time to transfer and is also often pointless since if a problem is to be fixed it must be possible to reproduce it from the basic project-files.

It is best to ZIP all files up and send as a single file (smaller size, easier to keep track of at this end and the ZIP will also serve as a backup if changes are made to the files):

1. GEO-files used
2. LOC-files used
3. v9: MD9-filesused, v8: PRD-file used
4. surface properties library (from folder ABSLIBS as selected in File | Prefefences, if used)
5. source directivity files (from folder SD, those used)
6. other files as a complement only after contacting CATT