DRC123 file format
General format
- DRC123 uses tab separated ASCII files for measurement
storage.
- Line delimiter is <CR><LF>.
- Column delimiter is <TAB>. On input any white space
delimiter is accepted.
- Lines starting with a single '#' are the file description.
- Lines starting with '##' are measurement parameters. In the
format ##key=value(s). The valid keys
depend on the specific file type.
- Lines starting with '## ' are informational only. They are
ignored on read.
- All other non-blank lines are measurement data. The meaning and the
number of columns depend on the specific file type.
- Columns must contain values, in doubt nan.
File types
Units and conventions
- All values use SI base units.
- nan values are ignored. They are taken as if no value has
been measured at a frequency. This usually causes interpolation to be
used.
- Differential values like the group delay refer to the interval from
the frequency of the last line with a not nan value to the
frequency of the current line.
I.e. if you have a group delay of 0.1 at 20.5 Hz and the last frequency
was 20.0 Hz then the average group delay in the interval [20.0,20.5] Hz
is 100 ms.
Target files
.target files are used to describe the transformation function
that should be applied to the played samples before they are passed to the
amplifier to precompensate for the room response.
## Generated by DRC123 V1.0
##Measurement=D:\TEMP\gcc\drc123\atPC.measure
##Measurement=D:\TEMP\gcc\drc123\atPC2.measure
##Freq=20.000000,20000.000000
##FreqBin=0.250000,0.005000
##NormFreq=80.000000,500.000000
##LimitGain=3.162278,0.200000
##LimitDelay=0.300000,0.050000
##InvertHighGain=0
##FilterMode=1
##DispGain=-20.000000,20.000000
##DispDelay=-0.200000,0.200000
#
20 1.33631 -0.3 1.0128 0.01217
20.35 1.82673 -0.0807 1.32063 0.15028
...
Columns
- Frequency [Hz]
- Gain for channel #1
- Group delay for channel #1 [s]
- Gain for channel #2
- Group delay for channel #2 [s]
Parameters
- ##Measurement
- Measurement files used to generate this target
response. This parameter may appear more than once.
- ##Freq
- Frequency range where the target response is defined (domain).
- ##FreqBin
- Width of frequency bins [Hz] and additional relative width.
- ##NormFreq
- Frequency range used for normalization of the target response.
- ##LimitGain
- Maximum gain and maximum gain change rate [1/s].
- ##LimitDelay
- Maximum delay [s] and maximum delay change rate [s/Hz].
- ##InvertHighGain
- Boolean, 1 if gain values above LimitGain should be reduced rather
than cut at LimitGain. This may prevent DCR123 from driving speakers
with frequencies that they cannot reproduce.
- ##FilterMode
- Bit vector. 0 = no filter, 1 = subsonic filter, 2 = supersonic filter,
3 = both.
- ##DispGain
- Y axis range of the gain graph.
- ##DispDelay
- Y axis range of the group delay graph.
Measurement files
.measure files are used to store the results of single room
measurements.
## Generated by DRC123 V1.0
##Mode=0
##Channels=0
##DiffOut=0
##DiffIn=1
##CalibrationFile=D:\TEMP\gcc\drc123\Teratec XLerate Pro.calibrate
##MicrophoneFile=D:\TEMP\gcc\drc123\wm-60a.microphone
##FFTSize=524288
##DiscardSamp=524288
##AnaSwap=0
##LineNotch=3,50.000000
##RefFreq=20.000000,20000.000000
##RefExponent=-0.200000
##RefSkipEven=0
##RefSkipRand=0
##RefMode=3
##RefVolume=1.000000
##RefFreqFactor=1.000000
##RefEnergyDist=1
##DispGain=-40.000000,20.000000
##DispDelay=-0.150000,0.300000
##DispVU=-40.000000,-12.000000,-6.000000
##AverageDelay=0.005521
##PhaseUnwrap=218232,18
# Response of 2.1 system with 18" sub measured in from of the PC
19.9584 0.67011 nan nan nan
20.05 nan nan 0.71198 nan
20.1416 0.61584 -0.0974 nan nan
...
Columns
- Frequency [Hz]
- Gain of channel #1
- Group delay of channel #1 [s]
- Gain of channel #2
- Group delay of channel #2 [s]
Parameters
- ##Mode
- Measurement mode. 0 = noise, 1 = sweep.
- ##Channels
- Last measured channel. 0 = stereo, 1 = left, 2 = right.
- ##DiffOut
- Boolean, enable differential output.
- ##DiffIn
- Boolean, use right line in channel as reference.
- ##CalibrationFile
- Used sound card calibration file if any.
- ##MicrophoneFile
- Used microphone calibration file if any.
- ##FFTSize
- Cycle length of the measurement [samples].
- ##DiscardSamp
- Number of discarded samples at the start of the measurement.
- ##AnaSwap
- Boolean, swap left and right channel on input.
- ##LineNotch
- Line frequency notch. First number = number of harmonics to suppress.
Second number = line frequency.
- ##RefFreq
- Frequency range with intensity in the reference signal.
- ##RefExponent
- Energy distribution of the reference signal. dP/df ~ fRefExponent,
0 = white noise, -.5 = pink noise, -1 = brown noise.
- ##RefSkipEven
- Boolean, do not use even frequencies.
- ##RefSkipRand
- Boolean, skip some random frequencies in stereo mode to break
symmetry.
- ##RefMode
- Kind of the reference signal. 0 = mono, 1 = left channel only, 2 =
right channel only, 3 = stereo, 4 = differential. Ignored on input.
- ##RefVolume
- Volume of the reference output [0,1].
- ##RefFreqFactor
- Minimum factor to the next reference frequency.
- ##RefEnergyDist
- Distribute energy of unused frequencies to their neighbors.
- ##DispGain
- Y axis range of the gain graph.
- ##DispDelay
- Y axis range of the group delay graph [s].
- ##DispVU=-40.000000,-12.000000,-6.000000
- Range of the VU meter [dB]. First number = start of the green bar,
second number = start of the yellow bar, third number = start of the red
bar. The red bar ends at 0 dB FSR.
- ##AverageDelay
- Average group delay of the measurement [s].
- ##PhaseUnwrap
- Number of phase unwraps and number of indeterminate phase unwraps.
Sound card calibration files
.calibrate files store the result from a sound card calibration.
## Generated by DRC123 V1.0
##Mode=0
##FFTSize=131072
##DiscardSamp=65536
##AnaSwap=0
##RefFreq=10.000000,20000.000000
##RefExponent=-0.500000
##RefSkipEven=1
##RefMode=3
##RefVolume=1.000000
##RefFreqFactor=1.000000
##RefEnergyDist=1
##DispGain=-30.000000,10.000000
##DispDelay=-360.000000,360.000000
##DispVU=-40.000000,-12.000000,-6.000000
# Terratec XLerate Pro, Aureal Vortex 2 (AU8820) based sound device
9.8876 0.4175 nan nan nan 0.97078 nan nan nan 0.00001 nan nan nan
10.6201 nan nan 0.41428 nan 0.97067 0.00003 0.00001 nan nan nan nan nan
11.3525 0.4343 0.01095 nan nan 0.97054 0.00002 nan nan 0.00000 0.09924 nan nan
...
Columns
- Frequency [Hz]
- Loopback gain from left output to left input
- Loopback group delay from left output to left input [s]
- Loopback gain from right output to right input
- Loopback group delay from right output to right [s]
- Differential gain between left input and right input
- Differential group delay between left input and right input [s]
- Cross talk gain from right input to left input
- Cross talk group delay from right input to left input [s]
- Cross talk gain from left input to right input
- Cross talk group delay from left input to right input [s]
- Intermodulation amplitude of left channel (optional)
- Intermodulation amplitude of right channel (optional)
Parameters
- ##Mode
- Measurement mode. 0 = stereo loopback, 1 = left loopback, 2 = right
loopback, 3 = differential loopback.
- ##FFTSize
- Cycle length of the measurement [samples].
- ##DiscardSamp
- Number of discarded samples at the start of the measurement.
- ##AnaSwap
- Boolean, swap left and right channel on input.
- ##LineNotch
- Line frequency notch. First number = number of harmonics to suppress.
Second number = line frequency.
- ##RefFreq
- Frequency range with intensity in the reference signal.
- ##RefExponent
- Energy distribution of the reference signal. dP/df ~ fRefExponent,
0 = white noise, -.5 = pink noise, -1 = brown noise.
- ##RefSkipEven
- Boolean, do not use even frequencies.
- ##RefSkipRand
- Boolean, skip some random frequencies in stereo mode to break
symmetry.
- ##RefMode
- Kind of the reference signal. 0 = mono, 1 = left channel only, 2 =
right channel only, 3 = stereo, 4 = differential. Ignored on input.
- ##RefVolume
- Volume of the reference output [0,1].
- ##RefFreqFactor
- Minimum factor to the next reference frequency.
- ##RefEnergyDist
- Distribute energy of unused frequencies to their neighbors.
- ##DispGain
- Y axis range of the gain graph.
- ##DispDelay
- Y axis range of the group delay graph [°].
- ##DispVU=-40.000000,-12.000000,-6.000000
- Range of the VU meter [dB]. First number = start of the green bar,
second number = start of the yellow bar, third number = start of the red
bar. The red bar ends at 0 dB FSR.
- ##AverageDelay
- Average group delay of the measurement [s].
- ##PhaseUnwrap
- Number of phase unwraps and number of indeterminate phase unwraps.
Microphone calibration files
.microphone files are used to compensate for the response
function of the microphone and the mic amp. DRC123 cannot create
microphone calibration files. You need this data from third party.
# Panasonic WM-61A electret cardridge, aka Monacor MCE 2000
# from http://drc-fir.sourceforge.net/
20.00000000 1 0
1000.000000 1 0.0000174532925
2517.141803 1.002015952083772 0.0000173344351
...
Columns
- Frequency [Hz]
- Gain
- Group delay [s]