This Readme file contains
last-minute product information for DIRAC 6. For full instructions on
using DIRAC, please see the DIRAC help file.
Table of Contents
- Update and upgrade
DIRAC with the HASP key
from the previous version
problems and issues
to use the stimuli on the CD
to contact technical support
Follow these steps to install DIRAC on your computer:
- Insert the DIRAC CDROM in
the CD drive.
- If AutoRun is enabled, you
will see a menu allowing you to install the software. If AutoRun is not enabled, you will have to run
Setup.exe from the
Setup folder on the CDROM.
- When the 'File Download'
dialog is displayed, select 'Run this program from the current
- If a security warning is
displayed, select 'Yes' to proceed with the installation.
- Wait untill DIRAC has been
installed, and click 'Finish' to complete the installation
- If you received a HASP key
with DIRAC, also select 'Install HASP driver' from the menu, or run HASPUserSetup.exe
from the HASP folder on the CDROM.
If the above does not work for
some reason, navigate to
the "Setup" folder on the CDROM and run the "Setup.exe"
Follow these steps to run DIRAC:
- Begin at the Windows
- Click the Start button.
- Select Programs.
- Select the DIRAC program
group and click the DIRAC 6 icon.
start DIRAC with the name of an impulse response file on the command
line. Example: "DIRAC measurement.wav". DIRAC will open the impulse
response and display it in an Impulse Response window.
start DIRAC with the name of a project file on the command line.
Example: "DIRAC project.dpj". DIRAC will open the project and display
it in the statistics window.
Follow these steps to remove DIRAC from your computer:
- Begin at the Windows
- Click the Start button.
- Select Settings, and then
click Control Panel.
- From Control Panel, double
click "Add/Remove Programs".
- Click the
- Highlight "DIRAC 6".
- Click the "Add/Remove"
button. This removes DIRAC from your computer.
Update and upgrade information
DIRAC 6 replaces earlier versions of DIRAC and requires an update of
your HASP codes.
Installing DIRAC 6 does not require you to uninstall earlier versions,
provided you do not install DIRAC 6 in the same folder as an earlier
DIRAC 6 requires a new sound device setup and new system
calibrations after an upgrade from earlier versions.
Using Dirac with the HASP key
Follow the Installation instructions in section 1 of this document, to
install the HASP driver.
Plug the HASP key in any parallel port (or USB port if you have an USB
HASP) before using the software.
The HASP key is fully transparent to the operation of the computer and
any connected peripherals.
Changes from the previous versions
Changes from version 5.5 to version 6:
- Added the possibility to display a parameter value versus the source-receiver distance.
- Added context menu commands to move groups and files up and down in the project tree.
- Added option to edit file properties of multiple checked files in the project window.
- LFC calculated from omni-bi measurements and LF calculated from probe measurements
- Updated STIPA calculations cf. IEC 60268-16 Ed.4.0 (removed female and separated 125 and 250 Hz bands)
- Updated speech parameters window
- Added MTF graphs
- Added new parameters for ISO 3382-3: DL2,S, LPA,S, LPA,S,4, rD and rP.
- Added new level parameters: Lmin, Lmax, Lpeak and LN with A/C/Z frequency- and F/S time-weighting
- Display Leq and derived values for measurements with pink stimulus
- Added measurement position X,Y,Z coordinates, source- and receiver-position, and rotation to file properties
- Time window settings (reflection / transmission) are now saved in the file
- Added the use of measurement setups in the measurement window
- Added 'Add to project' option on AutoMeasure tab to automatically insert the new measurement in a parameter graph.
- A-weighted dB level displayed below VU meters when level calibrated
- Added support for the "Echo" speech sound source
- Added 'intermittent' measurements for Echo source and ISO 3382-3
- Added 'Mix Paste' and 'Normalize' functions (Edit menu)
- Added 'Copy Graph to Clipboard' and 'Export View Data' options to View menu
- Added 'Rotate to marker' and 'Set SR distance' to Edit-Rotate menu
- Added speech and A-weighting filters to Edit-Filter dialog
- Added 'Shaping Filter Designer' (SFD) to Process menu.
- System calibration extended to include 8 kHz octave band in support of ISO 3382-3
- Sound device setup window only displays available samplerates
- Added 32 kHz samplerate
- Improved detection of sound device capabilities
- Updated sounddevice calibration procedure (now called loopback test)
- Improved support for ASIO sound devices
- Allowed multi-select in File Open dialog (open multiple files at once)
- Multi-channel import
- Changed File Properties dialog to include more items
Changes from version 5 to version 5.5:
- Added directivity plot
- Added Echo Criterion parameter (Dietsch & Kraak)
- Added user defined Strength (Gxy)
- Added Filter dialog (Edit menu)
- Added Signal Generator (Edit menu)
- Added option to align channels (Edit menu)
- Added option to time-reverse (part of) a signal (Edit menu)
- Added (IronPython) scripting
- Added Pulse Train Splitter (for scale model measurements)
- Updated STI/STIPA/STITEL and RASTI calculations in support of IEC 16268-16 Ed.4
- Changed system calibration to support free-field omni-bi calibration for LF measurements
- Added option to perform graded amplification to Amplify dialog.
- Separate amplification setting for each channel.
- Implemented ISO 9613-1 (sound absorption in air) for scale model calculations.
- Added air pressure entry in scaling dialog.
- Many smaller improvements and bugfixes (see helpfile for complete list)
Changes from version 4.1 to version 5:
Now uses the new Windows
audio engine (CoreAudio/WASAPI) on Vista and Windows 7.
New parameters: G80 (early strength), GL (late
strength), GEL (early lateral sound level), LG (late lateral sound
level), ER (energy ratio), ST (user-defined support), I (sound
intensity), D (level difference), TR (treble ratio), PNR (peak to noise
Improved flexibility of the impulse response views with
easier zooming and panning in all directions, and cursor lock to the
graph. The magnitude and phase spectrum views have more smoothing
options and a frequency scale in octaves or decades.
The new project tree for the parameter graph provides a
better overview of the project and more ways to graph individual and
aggregated measurements. The reference curve option makes it very easy
to compare measurements.
Significant speed improvements when calculating multiple
parameters for a project.
A revised measurement window that now contains all
relevant options and settings, yet provides a better overview and more
flexible measurement setups, such as the support for very long sweep
Better support for scale model measurements with batch
processing of files for post-averaging and scaling.
Now supports multiple level calibrations, based on sound
pressure or voltage.
Automatic notification and download of software updates.
Simplified error and problem reporting.
Changes from version 4.0 to
- Added the Sound
Insulation Index (SI) parameter described in the ENV 1793-5 standard.
- Added the option to save
WAVE (.wav) files without Dirac specific information. This makes it
possible to use WAVE files created by Dirac with software that does not
support RIFF INFO chunks.
- The Save Project Data
function now saves parameter values for both channels where possible.
- The Leq,
LAeq and LCeq
are now only available when the external impulse measurement method is
used, or when the measurement stimulus has a white spectrum (e.g. MLS
and lin-sweep, without source filter). For non-white stimuli, the Leq
is not valid due to the particular implementation in Dirac.
- The BR(L) is now only
available when a system calibration has been applied to the
measurement. The system calibration compensates for the influence of
the measurement chain on this system parameter.
- Asynchronous measurements
now result in higher INR values.
- The criterion for
displaying (and colouring) speech intelligibility values has been
changed. These values will be displayed in grey when, in one of the
relevant frequency bands, the INR is lower than 15 dB or the MTF cannot
- The default name for
saved tables and graphs now includes the project name.
- Fixed a software problem,
making the free field system calibration available again.
- Fixed software failures
that could occur while canceling auralisation calculations and while
- Sound devices are no
longer erroneously marked asynchronous during the sound device
- Decimal points and
comma's are no longer mixed in saved tables.
Changes from version 3.1 to
- Much improved
asynchronous measurement results. Asynchronous measurements can now
have almost the same quality as synchronous measurements. Asynchronous
measurements can be averaged to increase the INR. Measurements where a
CD or MP3 player can be used to playback an MLS or sweep stimulus are
important for instance when measuring the speech intelligibility of PA
systems in train stations, stadiums, airport halls etc.
- Option for manual entry
of SNR values for STI calculations. Using asynchronous measurements
with pre-averaging, you can now measure the noise-free speech
intelligibility. Later you can easily investigate the impact of noise
by manually entering different SNR values.
- Auralisation function.
The auralisation function will automatically resample the IR to match
the sound material. You can correct the results for the frequency
response of the sound source that was used to capture the IR to remove
the colouring caused by the source.
- New parameters: C30,
Cx, Dx, IACCx,
RT, Tx, Hallmass (H), Bass Ratio (BR(RT) and
BR(L)), LAeq, LCeq,
Magnitude Pink (3dB/octave compensated magnitude view). You can specify
your own integration intervals for Clarity (Cx),
Definition (Dx) and Inter-Aural Cross
Correlation (IACCx). You can also define a
custom decay range for the reverberation time (Tx).
All user defined parameters are available in table and graph formats
and can be saved, copied, printed etc.
- User defined parameter
tables. In addition to the pre-defined tables for reverberation, energy
ratios, spaciousness etc., you can now define your own tables to
contain exactly the parameters you need for the job at hand.
- Project save and load
functions. When working with a large number of measurements, this can
be a big time-saver. The group setup in the statistics window, and the
files contained in these groups can now be saved in a project file. The
project file can later be opened again for quick access to all files in
the measurement session.
- Calculate and export
multiple parameters in a single operation. You can now specify any
number of parameters that should be calculated for a particular
project. The results for all these parameters for all impulse responses
in the project are written to a file that can be opened in a
- Forward integration view.
- Undo function for
waveform Edit operations. The number of operations that can be undone
is only limited by the size of your disk drive, so for all practical
purposes the Undo is unlimited.
- Overlays in time and
frequency domain views. You can now compare measurements graphically to
the level of individual reflections. The impulse responses can be
aligned perfectly based on a cross-correlation, and you can quickly
switch the foreground and background curves.
- Optional linear scale in
ETC view. By popular request the linear scale for the Energy-Time
Curve, or reflectogram, is back.
- Optional grid in time and
frequency domain views. You can now also change the graph colours.
- Faster sound device
calibration procedure supporting a wider range of devices. Dirac no
longer requires that the sound device (driver) supports the mixer API.
Only the wave API is required. This enables the use of many sound
devices that use their own proprietary mixer software.
- Support for 24- and
32-bit sound devices and .wav files. The maximum sample rate was
increased to 192 kHz for high quality 1:10 or 1:20 scale model
- Option to change the
sample size and sample rate of a measurement using a high quality
- Optional bandlimited
sweeps to protect the sound source.
- AutoMeasure can now also
be based on a time interval instead of a trigger signal. This is useful
for monitoring applications where a measurement must be taken regularly
regardless of the presence of any sound.
- Numerous smaller
Known problems and issues
A system calibration is only
valid for octave band values. E.g. calibrated Strength (G) and related
parameter values can only be obtained in octave
bands, not in third-octave bands.
you experience problems entering numeric values (such as gain
settings), verify that the Number's 'decimal symbol' differs from the
Currency's 'digit grouping symbol' as set through the Regional Settings
in the Control Panel on the Start menu.
In general, there must be no conflict between the Number and the
How to use the stimuli on the CD
The DIRAC CD contains a folder named 'Stimuli' containing MLS and Sweep
for use in asynchronous (or open loop) measurements. The stimuli in
are each 10 minutes in length and can be copied to any MP3 player. The
in .WAV format are each only 1 stimulus period in length and multiple
have to be concatenated prior to creating an audio CD. To create a CD
some of the .WAV format stimuli, please use the following steps:
- Open a .WAV stimulus of the
desired type and period.
- Use the Copy and Paste
functions on the Edit menu in Dirac to concatenate multiple periods
until the file has the desired length.
- Save the result of the
previous step in a .WAV format file without DIRAC specific information.
(Use the 'Save as type' pulldown).
- Use Windows Explorer (or
other software) to create an Audio CD containing the processed files.
How to contact technical support
after thoroughly reviewing this ReadMe file and the product
documentation, you are still having a problem with this software, you
can send in a Problem Report using an option in the Help menu, or you
can contact your local Bruel & Kjaer representative.
Check the support
information on the B&K website at: http://www.bksv.com/
Minimum hardware requirements
DIRAC runs on a PC with:
- A 1 GHz CPU
- Microsoft® Windows
- Microsoft® .NET
- 500 MB of available disk
- WSVGA resolution of 1024
x 600, WXGA 1280 x 768 or higher recommended
- Full duplex sound device
supporting CoreAudio/WASAPI or ASIO
- CD-ROM drive
In order to use DIRAC,
additional hardware is necessary.
The most commonly used hardware components are:
microphone with amplifier, or sound level meter with AC output.
loudspeaker with power amplifier or Impulsive sound source, such as a
blank pistol or balloon.
- Speech sound source.
We really hope that you
enjoy working with DIRAC.