CATT TUCT overview

CATT TUCT™ overview

TUCT™ was released with CATT-Acoustic v8.0j March 29, 2010 latest update v1.0h with
CATT-Acoustic v9.0b Dec 2, 2011.

Overview of the new CATT prediction/auralization software TUCT™:

TUCT™ stands for The Universal Cone Tracer and predicts echograms and room impulse responses offering several different internal algorithms depending on the room case, ranging from basic to advanced. In particular it offers very good ways to predict and auralize open cases (outdoor arena etc.) that traditionally often have necessitated making a faked closed model for most algorithms to work well, especially for auralization, and cases where flutter echos may be important. Also prediction and auralization in big indoor venues with high absorption will benefit. The core algorithms are based on various levels and combinations of actual and random diffuse ray split-up and are general so that as the algorithms are further refined and computer speed increases additional levels of actual split-up can be incorporated.

TUCT™ relies on the geometry modeling view/check and library handling (absorption, source directivity, HRTFs, headphones) of the CATT-Acoustic™ main program (CATT-A) that exports a file (.CAG) containing the data necessary and runs TUCT™. Everything previously learned regarding geometry modeling in CATT-Acoustic™ and old models can thus be directly used but all prediction and auralization is from v9 instead performed by TUCT™ in a simpler, more general and more flexible way.

TUCT™ is a near total rewrite from scratch but also includes some parts of CATT-Acoustic™ v8 such as Pixel rendering, an Image source model and Time trace that are adapted and extended to work with TUCT™ as separate tools in a more flexible and integrated way. Most parts of the CATT-Acoustic™ post-processing have no direct correspondence in TUCT™, they are simply not needed. The few remaining, still useful but not very often used, utilities are kept in the stripped down CATT-A.

Major differences between TUCT™ and the previous CATT-Acoustic™ v8 prediction/auralization:

prediction algorithms are more general and do not rely on reflection growth extrapolation like the RTC
auralization is based on the full reverb tail instead of recreating it in post-processing
no separate post-processing stage for auralization required, impulse responses are available for evaluation and convolution/listening directly after prediction
displays measures and graphs for both an energy echogram and an impulse response giving an indirect indication about the prediction reliability at low frequencies
no separate multiple source addition or auralization required, multiple source impulse responses are available for evaluation and convolution/listening directly after prediction
no separate convolution utility necessary, just click Play/Convolve for immediate listening, even for multiple sources like in a PA system
for multiple source (with different sounds) auralization MultiVolver VST™ and MultiVolver WCP™ (offline version) can be used, TUCT saves settings-file for easy integration
no separate relative calibration required to auralize positions within a room with relative levels preserved
can run in multiple instances (examples: one instance can perform an audience area mapping while another performs impulse response prediction for the same model, or one instance predicts one room and a second instance another room while a third is used to view old results)
many types of calculation results can be viewed in parallel (it can e .g. be useful to view the results of an early part Image source model together with the results of a full calculation to identify main early reflections)
direct or reflected sound can be mapped on all walls and/or audience surfaces at an interactively selected resolution via the new Surface rendering (similar to Pixel rendering but at a variable absolute spatial resolution allowing free model rotation and rescaling)
after a calculation, the effects on STI when changing background noise, overall level/eq and STI type can be studied interactively including the effect on map statistics, a separately calculated noise map can be used as background noise.
very few result items have to be decided on before prediction, old results can be recalled, displayed and analyzed again in new ways (in most cases also if new measures or analysis/display features have been added after the original calculation)
simple sequence processing for running several calculation in sequence
no use of PLT-files (in v9 a new PL9-format is used for the main program for geometry/view check and directivrty grahpics, TUCT™ can export to PL9 for presentations or side by side comparisons).
flexible structure for adding future functionality and measures

Licensing:

for v8 users v9 is treated as an update and has separate Prediction and Full auralization versions

A basic TUCT™ screen showing main windows (further open windows as icons below)

The Main:Actions window

is an interface to main prediction options and while processing it indicates processing steps, estimated processing times
and % CPU used while processing.

Predict SxR predicts echograms and impulse response for each selected Source x Receiver (SxR) combination and utilizes multiple CPU cores. Three different main prediction algorithms ranging from basic to advanced. The algorithm choice depends on the room type and the level of details and auralization quality desired. Higher order B-format (2nd or 3rd) can be selected for external decoding and 5-ch mic setups can be used for ITU 5-ch surround. In addition one of two internal methods is automatically selected to create the impulse responses depending on case:

Map measures predicts measures over a defined audience area receiver map and utilizes multiple CPU cores.
Optionally STI and U50 background noise can be from an SPL map of actual noise sources:

Map direct sound predicts direct sound SPL over a defined audience area receiver map and creates
source delay and closest source maps, utilizes multiple CPU cores:

For all the above the latest prediction settings are stored on a project basis so when a new version of the same model is
made the previosuly used settings are preselected.

Predict SxR and Map measures can be run via a Sequence (batch) processing:

The Main:Show 3D window

Displays the room model with many options such as face coloring and switching on/off 3D elements and save/load of
named global or project-specific 3D-views:

Detection and display of ray-leaks due to model errors (gaps or warped planes):

Displays results from direct sound mapping. Mouse-over value readout and auto-scale option:

SPL:

Shortest delay (useful for optimizing source delays):

Source group with shortest delay (useful for optimizing source delays):

Displays results from audience area mapping of measures (SPL, STI, D50, etc. plus SPL(t)). Mouse-over value readout
and auto-scale option:

SPL(t) , i.e. step through the SPL map in time as Echogram, Buildup (forward integrated) or Decay
(backward integrated) with variable time steps:

watch each map point echogram and some basic measures as the mouse is moved over the map area:

watch the SPL(r) vs log(r) regression lines for the DL2 and DLf measures (ISO 14257) suggested for use also in
open-plan office via ISO 3382-3 (now in draft). Flexible novel implementation via mapping of these DL-measures
giving values for many lines in the office and not just one ot two:

In addition to the regression lines behind the standard DL-measures, and the DLf and DL2 themselves, a more
useful DLf-based measure is introduced where each map point is simply normalized with the freefield SPL at the
same distance:

watch STI/CIS change as background noise, overall eq/level, masking on/off and STI type is varied and background
noise may be from an SPL map of actual noise sources. An STI limit can be selected (see white rectangles below
indicating values < 0.65):

color STI map according to defined ranges (background noise raised) :

watch U50 change as background noise is varied, background noise may be from an SPL map of actual noise sources:

special STI statistics (data can be copied for further processing):

general measure statistics (data can be copied for further processing):

octave-bands, linear wide-band or A-weighted wide-band maps
spreadsheet map export separted into layers (such as a balcony
audience above a floor audience), the map viewed or a selected
set of all measures

The Main:Show 2D window

Displays the room model in plan, side and end views with mouse zooming/panning. The Plan/Section Cut z checkbox enables a moveable z (height) cut-plane to make it easier to see source, receiver and audience details in a room with many ceiling details (see heavy horizontal red line in figures below):

Zoomed and without z-cut:

Displays predicted measures for a selected Source x Receiver (SxR) or Source sum x R (*xR) combination:

watch STI/CIS change as background noise, overall eq/level, masking on/off and STI type is varied:

watch U50 change as background noise and overall eq/level is varied:

mean absorption coefficient graphs with min, max, mean and path distribution:

mean scattering coefficient graphs with min, max, mean and coefficient distribution:

T-30 statistics, useful for understanding a room's acoustic properties and selecting approriate calculation parameters:

octave-bands, linear wide-band or A-weighted measures

Displays echogram-related results for a selected Source x Receiver (SxR) or Source sum x R (*xR) combination,
optionally only the energy echogram E can be displayed (red curves below):

squared impulse response, in dB:

energy echogram, plus squared impulse response in dB (for comparison, same integration time). Further options,
not shown on this figure, is reflection smoothing and reflection classification (the latter mainly for control rooms):

Schröder curve (backwards integrated IR) with optional, EDT, T15 and T30 regression lines:

Schröder curve normalized with all bands as a backdrop:

Forward integrated IR, indicates sound build-up:

Echo-criteria (EKgrad) for music and speech (green) signals:

a novel type of directional display combining incidence angles and time arrival, variable microphone types
including the patent pending Sector mic™:

polar diagrams as function of arrival time, variable integration time and microphone types including the patent
pending Sector mic™.

Displays impulse response (IR) related results for a selected Source x Receiver (SxR) or Source sum x R (*xR) combination:

displays IRs for: W, X, Y, Z, X Cardioid, Rotating microphone with selectable microphone types (including the
patent pending Sector mic™), binaural, XY-stereo, Blumlein stereo:

Rotating mic. The Rotating mic direction is indicated in the 3D display, with the Sector mic™ the mic sector outline is
indicated on walls making it easy to identify reflections

directly play anechoic sounds convolved with IRs (Play/Convolve)
play the anechoic material for reference (click Play/Convolve while holding down the left ctrl key))
directly play the selected IR "as is"
directly play the selected IR convolved with a program material filter, such as AES (Play/Convolve)
optionally save as WAV when playing (separate comprehensive IR export available)
directly play/save with relative calibration

Main:Impulse Response Detail

Displays detailed IR-related results for a selected Source x Receiver (SxR) Source sum x R (*xR) combination:

IR squared in dB (raised half cosine windowing applied and shown):

frequency response linear frequency scale:

frequency response log frequency scale:

spectrogram with many resolution options:

The following displays are independent of the Main: windows and can be viewed in parallel.

Pixel rendering

Displays direct or reflected sound at walls and/or audience surfaces at every visible pixel:

Surface rendering

Displays direct or reflected sound at all walls and/or audience surfaces at a selected spatial resolution, since the resolution is not pixel-based the model can be rotated after calculation. Mouse-over value readout and auto-scale option.

Image source model (for specular reflection detail)

image sources can be saved and will be reloaded next time the window is opened
interactive reflection paths (click on a reflection and see the path, or step through the
echogram in time), view the echogram of multiple sources color-coded according to
reflection order, arrival-time or source. Further options, not shown on this figure, is
echogram smoothing and reflection classification options (mainly for control room use):

show surfaces involved in each reflection:

display all paths (with an option to show only the wall hit-points):

display all image sources:

view integrated and/or ear-smoothed echogram (to reveal reflections that hide behind each other in the
echogram), reflection classification:

Time trace as function of time

including AVI video export
ray coloring according to SPL:

ray coloring according to reflection order:

ray coloring according to source:

The following are tools independent of the room model loaded:

WAV-file player

Walkthrough convolver

The Walkthrough convolver uses SIM-file impulse responses that contain all necessary information.
For normal auralization in SIM-files are no longer used but they can be exported:

Overall features

2D and 3D clipboard copy and export to Meta, BMP and PL9 (CATT v9 vector graphics)
for all 2D and 3D windows.
direct printing of main 2D and 3D windows contents
interactive (mouse click/drag) scale and time change for echograms, impulse response
and similar graphs.
mouse-over value readout for all graphs and map values
can directly display and evaluate the echogram/IR and auralize for multiple sources such
as in a PA system, an example with two sources A0 and B0 with direct sound arrivals indicated:

room model data for view/export:

calculated measures for view/export (for any combination of sources and receivers):

export of all measures to MATLAB® .MAT format
export of IRs in several formats including MATLAB, SIM and WAV (separate files or multi-channel).
export of binural, B-format (also 2nd and 3rd order), 5-channel (actual mics, coincident, via BPhromer™ via
Sector mic™), stereo (XY and Blumlein), mono mics (omni, cardioid, supercardoid, hypercardioid, fig-of-8)
B-format WAV IRs can be further analyzed in ReflPhinder™ or convoled in real time via the new
MultiVolver VST™released with v8.0j and/or the offline MultiVolver WCP™ convolver (released
with v8.0k) both using the same setup-files.

export for use of IRs in CATT-Walker™:

export of "HeadScape" IRs for head-tracking (for Lake Huron/CP4 users or the Walkthrough Convolver):

batch convolution for any combination of source and receivers and/or source sum IRs making it possible
to very quickly listen to a sound system with various configurations. If the WAV-file/Player is open the
resulting WAV-files are added to a list for direct playing.