I don't disagree with the manual, in fact my example supports this (You have 20 bands split equally between a number of channels).
It doesn't say the EQ is 20 band per channel, just that it has 20 bands.

Looking at the DSP data sheet it's actually more restricted than my example...
This equalizer accelerator circuit (EQ) can make a two-channel equalizer of 10 second-order sections per channel or a four-channel equalizer of 5 second-order sections per channel depending on the value of AD register bit TWO-FOUR (see Table 9). It takes an input sample set of 2 (stereo) samples or 4 (stereo front and rear) samples via 4 input registers. It delivers an output sample set of 2 or 4 samples via 4 output registers. All input and output registers are 18 bits wide.

http://www-us.semiconductors.philips.com/acrobat/datasheets/SAA7705H_1.pdf (Url supplied by Tony in a previous thread, I assume it's still the DSP in use)
So it looks like a non starter... =(

Jazz
(List 112, Mk2 12 gig #40. Mk1 4 gig #30. Mk3 1.6 16v)