How to convert a .SDIR Logic Pro Space Designer Impulse Response to .wav audiofile?
Audacity can do it!
How?
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1 – fast way:
– open your system library (/Library/Audio/Impulse\ Responses)
– choose the desired .SDIR and do: open with… Audacity
– Audacity will open up a new project with the right sampling rate of the .SDIR
– Audacity will not recognize the bit-depth of the .SDIR and open the file as 32/24/16bit (set in the preferences dialog, Audacity will open the file usually as 44.100 Hz 32bit audiofile)
– export the audiodata to a mono/stereo/multichannel wav (or sth else)
– when exporting the impulse response to a 16/24bit wav from the Audacity project a bit-depth conversion will be done
– I would avoid this with (2)
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2 – very precise way:
– open your system library (/Library/Audio/Impulse\ Responses)
– open the .SDIR with the Impulse Response Utility
– check the Reverberation Time of the .SDIR (sometimes given also in the filename)
– check the numer of channels given for the .SDIR (2 or 6 or 10…)
– check the filesize of your .SDIR (bytes) in the Finder
– calculate the sampling rate with the following formula by estimating the bit rate:
filesize * 8 / estimated bitrate / no of channels / reverberation time = sampling rate (+ some samples of the header)
the output should be close to 44100 Hz, 48000 Hz, … , 96000 Hz
example: 02.6sMyStudio-OSD.SDIR
3783496 bytes * 8 / 24 (estimated) / 10 channels / 2,6 s = 48506 Hz –> ok 48k !
– calculate the bit-rate with the following formula by guessing the sampling rate:
filesize * 8 / estimated sampling rate / no of channels / reverberation time = bit rate (+ some dirt from the header samples)
the output should be close to 16 or 24 bits
example: 02.6sMyStudio-OSD.SDIR
3783496 bytes * 8 / 44100 / 10 channels / 2,6 s = 26,4 bits –> wrong !
3783496 bytes * 8 / 48000 / 10 channels / 2,6 s = 24,2 bits –> ok 24 bits !
– open Audacity and create a new project
– go to the system preferences and set the project quality (in this example to 48000 Hz and 24 bits)
– drag and drop a .SDIR file into Audacity
– export the audiodata to a mono/stereo/multichannel wav (in this case 24 bit)
– in this case no samplerate conversion or bitrate conversion will be done
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if you don’t care if Audacity makes a samplerate-conversion when importing/exporting just open the file or drag it into a new project.