hhmm only a page back
@Frank_fjs mentioned that the decoding is done on the CPS2 hardware itself?
Looking at an image of one of these amps there appears to be nothing custom or unique on them just some NEC opamps? if those are the key to 'decoding' the audio could you not make a standalone decoder board with those and pass line level audio through that to any old stereo amp?
The secret is hidden in plain site, only a hand full knows about it, me included
CPS2 hardware has no decoding software or hardware, the DL-1425 CAPCOM-Q1 it is not a DSP, it's a "sophisticated" mixer. QSound technology is filter based, as Oliveira said, it rely on equalization of the signals outside the CPS2 board that also mess with phase shifts to create the desired effect. Oliveira talk about the effect of sound waves canceling each other out in middle air, here an example.
Download
this file, play it with any stereo equipment
THAT HAS SPEAKERS, it doesn't work with headphones, it might work with smartphones IF they have stereo speakers, you can use your SMART TV but you have to turn the sound enhancements off. You should hear a whistle (it doesn't need to be loud), slowly walk around the space you are at and you'll notice that in some areas the sound is louder (
constructive interference) and in some places the sound it's gone or you can barely hear it (
destructive interference), that is sound waves canceling each other out in the middle of the air in real time and this is the principle QSound uses to trick your mind.
About the hardware, take a closer look again and ask yourself this, why it needs 6 operational amplifiers (two per chip) to amplify a stereo sound and why there is so much polyester caps on that board? Polyester caps and opamps, why they are used for? Frequency filtering, phase shift. I don't have the hardware but to me the opamp closer to the RCA socket is doing some
summing and
differential work (this is de basic of audio matrix decoding), not to say if the cabinet uses some passive crossovers near the speaker.
Yes it's possible to do a decoder and use it with another power amplifier, that would be fine if you use the same opamp configuration/filtering/matrix decoding.
I've developed my own ASP (Analog Sound Processor) to do something else.
It doesn't decode QSound but it can work something close to it, you can try
this sample, the
Ryu Stage from
Super Street Fighter, same rules apply, it only works with Stereo Speakers and it doesn't work with headphones. You should notice a wider stereo and some taiko drums and
hyōshigi (拍子木) in th distance, it works great with Smart Tv's, play with the sound enhancements until you notice some depth to it.
