Is there such a thing as audiophile parametric eq?

For $350 (including mic) get the Behringer DEQ2496. Only you can decide if its audio quality is "audiophile". IMHO the outboard DAC would be an unnecessary complication. If you decide not to keep it in the signal path (and I bet you will) it is still well worth the price just as a spectrum analyser.

What mid bass frequencies are you tryind to tame?

As far as I am concerned, notch filtering is only effective below 100 HZ. Above 100 Hz the problem of room size comes into play. 100 Hz = roughly 10 feet of wavelength, which means the distance between peak and trough is only 5 feet. At 200 Hz the distance between peak and trough is a mere 2.5 feet. This means you only have to move the microphone a couple of feet to get a totally different response from room modes.

Therefore if you try to PEQ "room mode" notch filter above 200 Hz then you are basically chasing your tail...move the mike a foot and you get a different plot. So don't go there unless you are correcting a deficiency in the system or severe seating position problem (like up against a wall). I may be a bit weird but I expect my system to sound good from all around the room...only three feet and less from walls do I normally expect a poor frequency response.

Also remember that notch filters are quite sharp....so they introduce phase distortion. Phase distortion is unimportant at less than 100Hz as you can't even tell which direction these low frequency sounds are coming from. This is not the case above 100 Hz...so a sharp filter above 100 Hz may cause some audible degradation...it may change the timbre of sounds.

I run my Behringer PEQ ONLY to the subwoofer signal for these very reasons.

Shadorne, I'm not absolutely sure what the frequencies are. I think there's a kind of large peak around 200 Hz. I've built bass traps that make the lower bass quite consistent around the room. My speakers are Infinity Preludes that I've separated the subwoofer from the full range tower to give greater placement flexibility and I've positioned them as best I can for a good presentation of depth and also working around the limitations of this being a home theater as well. Are my peaks the sort of thing that should respond well to repositioning withing a foot or so of where they are now? Are there other acoustic treatments that I could use?

Thanks

Jlambrick...You say "I'm not absolutely sure what the frequencies are". All the more reason to get that Behringer. Its spectrum analyser (also called Real Time Analyzer, RTA) will show you what your problem is. No matter how you fix the problem, room treatment, equalizer, build a new room, understanding the problem is the first step. And, although equalization has theoretical faults, as Shadorne points out, in practice the benefits sometimes outweigh them.
So I say... get the Behringer as a spectrum analyser. Then see what equalization does for you. Trust your ears.

Yes if you love music that runs through one it is an audiophile's parametric equalizer. There simply aren't any rules in this hobby. No standards commision demanding that if something is to be granted the name audiophile it must meet the following criteria. For that matter anything that makes music that the listener loves is by definition audiophile. I don't agree with them much of time but its their party. I am not the sole arbiter of good vs bad. Is anybody's opinion better than someone else's who listens to music?
The best wine in the world is the wine you like best.