Wilson MAXX musicallity and sound

Dave-

I'm not putting all my focus on EQ. First, I want to know
what the frequency and pulse response look like, and use that info along with listening to position the speakers before applying any room correction.

With your rear ported speakers a foot out from the wall behind them, I doubt you're getting flat bass response.

I think that both exist in our speaker systems.

Absolutely. Most systems generate suprisingly high levels of IMD - basically it is a result of non-linearities in the system performance. An amp will not perform exactly in the same way when delivering 1 Amp of current as it does when delivering 1 milliamp. A speaker driver will not behave exactly the same way at the center of its travel when compared to sticking out one quarter of an inch and at its maximum Xmax of excursion (linear operating range where non-linearities are less than a terrible 10%). Therefore when amp and speaker cone are oscillating from one extreme to another (as it plays your favorite big band or rock tune) it causes intermodulation on the delicate voice of the vocalist - "the camera shake affects the photo" analogy.

IMD is rarely caused by speaker placement or the room. Most of what the room does (reflections) is an entirely linear effect and will not create any new frequencies. Only if things get loud enough to rattle and vibrate surfaces can a room or objects in the room create completely new frequencies not on the recording. This is when the vibrating surfaces add their own sounds. Typically these things will not go away with changing speaker placement or listening position...whereas an extra screw in the drywall or blutak tightening the catch on a cabinet door may help.

Kana813 said:

"I doubt you're getting flat bass response."

Duh, who is?? However, very precise placement has mitigated the most obtrusive nodes and balanced the bass vs. the midrange. Moving the speakers fractions of inches can excite nodes

That's way less important than the phase/comb/IMD effects that so gravely impact our musical enjoyment. When you take care of these issues, gone is the harshness, fog and veiling caused by these distortion components.

Dave

Shadorne, I don't know how to measure it or demonstrate it, but I believe there is IMD caused by the interaction of the two speakers with each other, not the room.

As a musician I often hear beat tones and difference tones when playing with others. These same kinds of things are going on between the two speakers. I've also experience the power multiplication when a group (say five trumpeters) gets totally in sync, totally in tune and playing with equal resonance. It's hard to explain, but when you experience it it's unforgettable. Anyway, getting the speakers ideally placed within their acoustic space and relative to each other is very important, no matter what we call it.

Dave

Dave-

Once again it would be interesting to see the frequency response of your Sumiko Master Set placement measured at your listening position.

With your rear ported speakers a foot off the back wall, I'm
sure moving your speakers fractions of inches will excite room nodes. The manual for your speakers(http://www.sumikoaudio.net/va/manuals/BeethovenManual.pdf) makes this very clear.

Using the TacT system, I have flat bass response down to 20hz using no boost. Speakers are placed to optimize imaging. I have digital EQ and XTC available, so I don't have to suffer with poor recordings.