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 echoes
may be important (but also the basic algorithm will catch flutter echoes).
Also prediction and auralization in big indoor venues with
high absorption will benefit. The core
algorithms are based on geometrical
acoustics (GA) with various levels and combinations
of actual and random
diffuse ray/cone 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, array
modeling, 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™ v8 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
v9.
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
a pressure impulse
response giving an indirect
indication about the prediction reliability at
low frequencies
- the pressure impulse response made it possible to include a comprehensive
treatment of early diffraction using a secondary
edge-source method based on a discrete Huygens
interpretation of Biot-Tolstoy (from v1.1a). This method has few
principle limitations when used in room acoustics
with finite edges, especially as compared to infinite
screen formulas. The documentation includes
a 20+ page whitepaper about how diffraction has been implemented,
and why a screen formula has not been used.
- 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™ (off-line 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)
- uses multiple processor cores
for all major processing functions, number of threads
automatically selected or specified
- 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. Same Principle options
for U-50 (and with v2 AI
and PI)
- 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 directivity graphics,
TUCT™ can export to PL9 for presentations
or side by side comparisons).
- several selectable mapping color
palettes.
- flexible structure
for adding future functionality and
measures
Major differences
between TUCT™ v2 and TUCT™ v1:
- the DLL Directivity
Interface (DDI) (SD2-files) for array modeling, in use
since 1998, will no longer be developed but is replaced
by a new and fundamentally improved source and array handling
using a flexible open array text-file format (CATT-Acoustic
Text Array, CTA) that after pre-processing is saved in a binary
format (CATT-Acoustic Binary Array, CBA) used at actual prediction
in TUCT v2. The CTA-format allows using symbolic
numerical and string constants and expressions, element filters (several
formats including encrypted), delays, polarity reversals, weights
and more. A unique and simple way of modeling line-arrays with high-frequency
line wave-guides, or other line elements, via modular Line ELements
(LELs). The CTA-format can also be used to create incoherent arrays
such as for noise line or array sources.
- a new source-file format using
SOURCE
data blocks to support the new source and array modeling.
To support old projects, that used the DDI, the v9.1 installation
will also include the last version of TUCT v1 (v1.1b)
adapted to work with v9.1. Which TUCT
version that will run depends on the source-file syntax used (SOURCEDEFS => v1,
SOURCE
data blocks => v2).
- electro-acoustic source IRs are
now re input voltage (i.e. not re 1 m on axis but re input) so it includes
the loudspeaker Sensitivity. Input can be set as voltage (dBV) or
acoustic SPL + microphone Sensitivity.
- when using natural sources,
such as an ideal omni for basic room acoustics, it only requires
adapting to the new source format syntax that for natural
sources is straightforward (via a direct conversion option)
and all the added functionality and improvements with
TUCT v2 will be available
- when using electro-acoustic
sources and arrays the new syntax is more involved since it also means
a paradigm shift especially regarding arrays but will give
many benefits for sound-system predictions in addition to also
be able to use the many TUCT v2 additions.
A basic direct
conversion is included.
- use
of a cockie-cut sector directivity .SDX as a replacement of the
DLL interface SECTOR0 SD2 that required using TUCT1.
- air absorption uses a distance-dependent
filter for direct sound and 1st order specular instead
of only octave-band values
- Map direct,
Rendering, Map measures and Predict
SxR are based on direct sound and 1st order impulse
responses and not only octave-band data.
- Both E and h include
direct sound, 1st order specular and diffraction (if
on) interference.
- an audience area mapping result
display option to view a subset of audience plane map results
for which Statistics is calculated
- import of prediction settings
from other projects
- sources are defined as either
coherent (typically loudspeakers) or inchoerent (typically
natural sources) where incoherent sources will not interfere.
- further added or updated measures from ISO 3382-1:2009
- Articulation Index (AI) and
Privacy Index (PI) based on ASTM E1130-08
- for all EDT, T-15, T-20 and
T-30 predictions it is ensured that the echogram/IR length
is sufficient to estimate valdid decays
- the new flexible Show
Graphs displays selected measures as function
of receiver id, distance from source (r or log2(r)) for any
combination of sources and receivers, octave-bands, A-weighted
and linear, E and h.
- C-7, T-15 and T-20 implemented
also for audience mapping and are display options for audience
mapping mouse-over Echogram that now shows the full length
(instead of the early part only) with Schröder integration
and optional EDT, T-15, T-20 or T-30 values and line regression,
graphics and data export
- a new Map
measures option SPL(t1..t2) where the direct and pseudo-direct
sound (such as a stage floor reflection) can be excluded
and only up to a selected upper time can be included, e.g. 1..50
ms or 5..80 ms
- the Src aim
option displays long aim lines (intersecting the closest surface)
- Pixel Rendering
shows mouse-over SPL spectra, calculates all bands directly and rescaling
the map does not require a recalculation
- Surface Rendering
shows mouse-over SPL spectra and calculates all bands
directly.
- the new Vertical
Slice Rendering maps the direct SPL across a
moveable vertical surface to e.g. show vertical array coverage
- Time Trace options
for reflector coverage and to show one ray at a time.
- Image Source Model
option to only show reflections above a certain SPL threshold
- for a fuller summary
of all additions and changes in v9.1/TUCT v2
see here.
Licensing:
- for v8 and v9.0 users
v9.1 is treated as an update and
as v8 has separate Prediction (with
demo auralization) and Full auralization versions
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