I posted this on the wish list and my wish was granted just yesterday, so I figured I'd move it on over here to programming.
Heres the background if your curious.

I've downloaded the kernel and with a little help have successfully set the number 9 and 10 EQ channels to the recommended settings.
Set the ninth band of each channel to have dB=0, f=100Hz, q=0.2 and the tenth band to have dB=0, f=10KHz, q=0.2

Now remember I'm totally ignorant so I'm probably going to make an ass of myself, but whatever...

The frequency settings I assume are for the bass and treble range adjustments, so If I wanted more or less bass from my increment changes in the bass slider in Hijack I could change that frequency to something else, right?
Bass is low frequencies so the 100hz setting on channel 9 is for the bass settings right?
If I did want to change it whats the theoretical maximum or minimum that I would use? 200hz? 50hz? And what about treble?
And on the same topic how did you (genixia) come up with your default recommendations?

I'm not really sure how all this works, I just know that it does and I'm thrilled.
I'll probably never change the recomended settings, but I'm still curious.

Thanks, again genixia!

Z~

Oh, and you can get the kernel here.

Put my settings down to experience, guesstimate and trial & error. I studied electronics and worked as a sound tech at university, so that gave me a starting point.

Q factor is defined as f/bandwidth, where the bandwidth is delimited by the -3dB points. So if you're adding +3db, you'll get a 2nd order parametric curve that ranges from 0dB gain at f-(BW/2) to +3dB at f and back down to 0dB at f+(BW/2)

With my suggested values, that means the -3dB points should be -150Hz and 350Hz for the bass, and -40KHz and 60KHz for the treble, which looks really wrong, but certainly doesn't sound that wrong. I'm getting more convinced that there is a bug in the player's eq code. The fact that the Q defaults to 0.55 is strange...

Anyway I'm still looking into these values and the player behaviour. It'll be interesting to see what the consensus is on the best values to use. I wouldn't push bass below 75 or above 200, likewise 6KHz and 12KHz for treble.

I'm going to have to download a white noise file to my empeg and dig out that FFT program on my laptop soon...