Well, I didn't really intend on this turning into an advice column interesting and potentially helpful though it has been.

I (think I) know what I want already and that is s/w I can run on my N900 that can reproduce the sound from the phone's microphone and play it into the headphones. Amplification is good and an equalizer might be even better too, but I already have headphones that sound great as they are (I guess they sound a bit bright to most people?), no matter what I listen to, so I'm not 100% sure that I would bother with an equalizer.

I really just wanted to specify something simple since it would be easier to do.

Thanks,

Max.