I am a newbie here. But I want to touch two points. My setup first:

Sony CD/DVD DVP-CX985V (hate it)
Denon AVR-2105 (drives center and surrounds)
Outlaw 2200 monos X2 (drives mains)
Polk LSi15
Polk LSiC
Polks RTi28 surrounds
SVS sub PC-Plus 20-39 (newest addition down to 16hz)

The Outlaw 7500 looks intriguing to me. I could buy it and use the 2200's for Surround BACKS. Or, I could bi-amp the LSi15's. But as it is, the LSi15's are rated at 250 max watts. I like moveis, but I love music! Classical and rock! My system benefits greatly from the addition of the 2200's and obviously the soumdstage is off because Denon is driving half the system. But in stereo, everything is great. The SVS sub may seem useless, but it ebbs into my next issue. With certain classical recordings (particularly large orchestral ones in rooms) the mics picked up "building" sounds and sometimes air. What showed me this? The SVS subs! It exposed too much!

My background: I am a violinist and composer. As part of my education, I had to take a class in physics/acoustics. That it was a POS at the time, but now things are really making sense to me. I cannot and will not presume to know 1/8th of anyone here so forgive me if what I say is common knowledge. Since what I am going to talk about is attempting to fuse real acoustic with solid state technology, it may not translate at all.

Let's say a violin plays his open G sting (the lowest all by itself. It is actually playing a fundamental and everynot in a harmonic series. And brass player could tell you those right away. In my example, the first note (fundamental) is the G, then the series of harmonics above (not always audible seperately) D, G, B, D, F, G > infinity

There's an Algebra function where the curved line (forgive me for not going to my books and checking) runs parallel into the Y or X axis and your eye will say that it will touch of you just followed it longer (off the paper perhaps) but mathematically it is impossible because a "0" cannot be in a certain part of the equation. Above, you noted the "F" in the series based on a G. Above that the harmonics get into the inaudible range and to dogs . . . they must hear some atonal stuff!!!
In that series, you also noted that the series at the first part outlines a harmless G Major chord. Andyone else playing a REAL B or D note would fit in well. Remember, that THEIR notes are also kicking off their own harmonic series notes. The obvious here is why #1 minor keys sound so "dark." They don't jive with nature's physics. #2 pianos are intentionally out of tune. M3's, M6's and M7's are all sharp. Nature, in fact, to OUR ears eventually shows it is out of tune. On an ocsilliscope (sp?) play a A1 and an A5 at the same time. The A5 will sound HORRIBLY flat. Yet orchestras do the equivalent of this all the time and make it work. You want to here the harmonic series yourself? Have a piano? Go to it. Press down the peddle that let's the note go on for a time. Make sure the room is utterly quite. Stick your ear as close to the box as possible. Hit only ONE note in the middle of the piano somewhere. Your ear will slowly discern the upper partials of the harmonic series. It will be kind of like looking at those crazy puzzles that turn out to be a saiboat or something after you look at it and then go into "blurry" mode.

How does this have anything to do with anything. Well, these harmonics at any performance are being picked up by the mics. They are being recorded. Many modern speakers, pre-amps, and amps (and even sources) claim to reproduce well outside the 20hz-20Khz range. Why? What more are they giving you? On my computer, I can record a perfect sin wave at 16hz. I heard and felt something. What did I hear? My math says that 16hz should be like a C#/Db. Did I hear an upper partial in the 20hz range? How complex must all of this seem to a processor.

Which takes me back to this story above about 48-50Khz anomoly. Without my interpretation of it first, I'd like you to consider what I said.

p.s. I am also torn between an all 2200 system or a 7500 amp system.