Another option would be for Hugo to be really nice and look up which bits you need to twiddle in the DSP to adjust its built-in bass and treble controls, instead of having to usurp two equalizer bands to do it.


That would be the ideal way

Yeah, band 9 is bass, 10 is treble. I can't remember the values off the top of my head, I'll check later when I'm at home.
The bits are packed as tight as they can go - so unless we can find some revolutionary method of quantum storage where each bit can hold more than one bit of information then we're out of luck. We could increase the range at the expense of resolution, which might be a problem for other people. Or we could look at the Q factor/frequency used - I guesstimated at the Q factor/frequency values, and they appeared to work farily well for everyone, but they certainly weren't optimised through any process. There are some unpublicised config.ini options that will change these in hijack.c. The problem is that I never completely reverse-engineered the format of the bytes used in them - I discovered the gain value byte fairly easily, but the f and Q format is still unknown to me. (In case you are wondering, I cheated by setting an eq band to the f and Q I was going to use, and wrote down the values )
There should still be a debug option in hijack.c where you can get the tone controls to pump out those hex values to the serail port, so if you wanted to play with this then it'd be a case of recompiling a kernel with this flag set. Then set the tone controls to 0, and the underlying bands 9 and 10 will be active once more - allowing you to try and find f/Q values that work better for you. (Remembering that as the tone controls currently stand you can only adjust +/-6dB).

You will however hit the channel lock bug. So I'd recommend unlocking the channels and trying this with the balance set all the way to one side. (This way, the other channel doesn't color the tone). If you find different values that work for you, write down the hex from the serial port - and then we can plug it into config.ini.

The implementation of the tone controls uses a LUT (look up table) for the gain values. I don't think it'd be easily possible to do math on the values to add the underlying eq bands gain value as you suggested. But I won't rule it out until I've looked at the code again. The only other option would be to petition Mark for a bit more flash so that we could increase the range/resolution.

Thoughts or comments?