Oh! And there it is, hiding in plain sight. Bass/Treble controls in the hardware DSP..

	dsp_write(Y_KTbas1,0x47a);

	dsp_write(Y_KTtre1,0x000);

I think maybe somebody should play with those two registers, and see what they do.. This is the correct way to do Bass/Treble controls, independent of the Equalizer..

Cheers