No lag that I can tell. I could easily adjust via the "phase" dial on the sub if needed, but the easiest way (for movies) is to add a foot of distance to the sub from the listener electronically. This would force my Oppo to delay the other channels by an equivalent time to keep the whole thing in phase.

As to "replacing" a peak, that's NOT what the 8033 does. It instead reduces the amplitude of the peak to match the mean (average) volume. Note that valleys are NOT boosted to the mean - this would require LOTS more power from the sub amp (possibly clipping the amp and damaging the sub). So any valleys in the response are left alone. Only peaks are attenuated.

You'd think that this would be only "half-effective," but the actual result is significant. I was contemplating an additional subwoofer to smooth my response (and may yet go that route), but the 8033 alone has improved the bass so much that I plan to live with this for awhile before spending another thin dime. The 8033 is that good.

I'd also say that my room is MUCH better than average for bass to start with. It's a large room with a "vent" in all four corners to other areas of the house (hallway, foyer, stairwell, and large opening to another room). Therefore, the room was "non-boomy" by design. Nevertheless, the 8033 made a huge difference for me. If it helped MY room that much, I'd think it would be even more effective for rooms with corner problems.

I'd also contend that you don't lose sub "headroom" by attenuating acoustic peaks. The sub placement and the room already add huge (but frequency-specific) efficiency at the peaks. Therefore, if the sub amp must play at 50 watts of output at 40 Hz, the equal-amplitude output at a 60 Hz peak may require only 5 watts. By amplitude-equalizing the peaks, the sub's amp actually works less hard to maintain a flat response. So if you want to think of it that way, you actually GAIN headroom by attenuating room peaks.

Cheers - Boom

My opinion is worth exactly what you're paying for it!