Well, thanks for your answer.
I could do that, but then I would have to give up at one of the other 2 sliders, and that's because of the way my sps works... Maybe I'll figure it out, we'll see. And it works pretty well like this, I mean if you want to boost the bass you set the first slider up, if you want the treble you set it down. Or if you want both of them to be boosted, you set it somewere in the middle.
And what you said about DSP's, I agree with you, at least partially. I don't use it on my stereo line, or if I use it I don't alter the sound so much. But for a bad to medium pair of headphones, or computer speakers, or even for someone that has nice hardware but is a bass (or treble) freak, this SPS works fine. Anyways, you get much better results than trying to do this from the Winamp equalizer.