A:Answer Not sure why you'd want to hook a digital sound processor up to a surround sound system with it's own digital sound processor built in. As for an equilizer, I'm pretty sure that's built in too. It has differenr sound modes to choose from, plus you can set the crossovers to match your speaker setup. They have crossover settings for the front speakers, center speaker, and surround speakers. These settings also adjust the sound output to your sub as well, making sure it helps fill in any gaps in the soundfeild.