You could experiment with ADPCM compression with FFMPEG.

I think I will have to. After trying to get QSound working in W95 according to TheMan's instructions, I can't seem to notice any difference in the sound of wav files.

Except now that I think about it, I have to pry the chip out of the card in order to do an A-B comparison? That sucks.

Does CSP.SYS need to be loaded for this to work in windows? Or is the mere presence of the ACV files in windows\system and the CSP files in %SOUND%\CSP adequate?

No, CSPMAN.DLL provides that functionality in Windows.

Attached are the Creative IMA ADPCM, A-law, and μ-law ACV/ACM CODECs and CSP modules that I'm currently using with the standard SB16 drivers included with Windows 95 OSR2. You'll want to disable or uninstall/remove the counterpart Windows' ACM CODECs, if present, and then just drop the Creative modules into the WINDOWS\SYSTEM directory, after which you should be good-to-go.

Also, where I've previously advocated the use of either IMA ADPCM or CTADPCM, I'm renouncing any recommendation of the latter unless a person desires or requires DOS playback of the converted files - the IMA ADPCM conversions are both audibly and measurably superior to those produced by the CTADPCM method.

could you be so kind as to post a sample WAV file encoded with IMA ADPCM? I can't find one on the net for the life of me

maxtherabbit wrote on 2022-10-02, 12:15:

could you be so kind as to post a sample WAV file encoded with IMA ADPCM? I can't find one on the net for the life of me

These aren't necessarily the best examples (concerning dynamic range), but here are a few comparison WAV files:

Iris. (2014). In the Clear [Excerpt]. On Radiant. Dependent Records.
♫ PCM (12.6 MB)
♫ IMA ADPCM (3.17 MB)
♫ CTADPCM (3.15 MB)

Iris. (2019). Joy Kill [Excerpt]. On Six. Dependent Records.
♫ PCM (12.6 MB)
♫ IMA ADPCM (3.17 MB)
♫ CTADPCM (3.15 MB)

Iris. (2019). Speak Out [Excerpt]. On Six. Dependent Records.
♫ PCM (14.3 MB)
♫ IMA ADPCM (3.59 MB)
♫ CTADPCM (3.57 MB)

thank you! It appears the CSP chip does not work in windows 98 using the default driver set. Going to try again using TheMAN's Qsound instructions to get it running

Success. Installing the revision 5 of the SB Win9x driver update package (SBW95UO.EXE on TheMAN's compilation CD) on my 98SE system was required to allow the CSP to function.

Source here:
Re: The Sound Blaster ASP chip, Q-Sound and Games.