Does anyone have any ideas on how empeg might have implemented the bass and trebble controls in the original ARM software?

I've had a look in the audio driver code (drivers/char/audio_7212.c) and can't see any ioctl that fits the bill. And, not being a hardware man myself, I can't see anything in any of the chip specs that might do this.

And so I can only guess that they're using software-based audio filters. Any ideas anyone?

Cheers
Paul