@fastninja12 - DSP -- Digital Signal Processing -- is just digital equalization. That’s all. It doesn’t imply room correction or anything else, nor anything automatic, though DSP is often used to accomplish room correction.
I have tried a fair number of equalizers, and the cleanest and best-sounding one I’ve used was the
Weiss EQ1 Mk2. It is a mastering parametric EQ that operates in the digital domain, so you would need to a/d the signal (as suggested by @audio2design) insert the Weiss, and then d/a it back again. The Lynx Hilo is one unit that could be used to do that -- it was at the top of an A/D/A bypass comparison done by a pro audio magazine (I think, Sound on Sound).
You can think of "mastering" in gear descriptions as meaning "high quality, two channel."
There are various other mastering-grade equalizers available, mostly parametric, and some wholly analog. Check Gearslutz or VintageKing. The EQs sold as mass-market audio products, I don’t think are as good.
That’s not to say you absolutely won’t find a good quality 1/3-octave analog EQ. Maybe you will. Last time I looked, the ones I could find were a few hundred dollars and aimed a mid-fi systems. I even had a rather well-regarded one (now out of production), meant for professional use, an
Audient ASP-231, which to me was inoffensive, but veiled the signal a little. (I am not taking a position on that eBay seller, just including the link for info.)
You’re looking for a unicorn. Good luck!
P.S. You might consider the
dbx DriveRack Venu360. I believe Sanders uses it in one of their high-end electrostatic speaker systems, so maybe it sounds good.
P.P.S. Other good analog EQs include the
Cello Palette line.
