frequency range for instrument vs speaker

Johnnyb, you explained it well. It takes a lot of effort and work to get it balanced across the broad spectrum. What I was trying to say is that the long wavelengths are multiple times the length of a typical listening position. So the SPL at 12ft (typical listening position) of a 20Hz frequency is going to be much lower that at 56.5 ft-, ie. the full wavelength. So to make the 20Hz frequency the same loudness at 12ft as shorter wavelengths will take a lot of power and then the loudness of the 20Hz frequency will be much higher as you move out to the 56ft range. Like you said, you have to work very hard to balance all of that out and get it to work. You are taking great pains to get the reflections and the sources to all come together at the listening position. I still doubt you can achieve a balanced 20-20k in a small room.

My Vandersteen 5A's have a bunch of pots in the back that adjusts frequencys from the very low bass to the midbass. Richard himself helped me with my setup and told me that the goal was NOT to get a flat frequency response...just s pleasing one. Flat frequency response is a-musical.

You are right. Full spectrum audio is achievable but takes a lot of patience and money. More than I have of either one. I certainly don't want to discourage the enthusiasts that are working to achieve that, but it is also good to share our failures and successes so others learn something from it. I'm pretty happy where I am with my system today. I think my large size and volume listening room combined with the wood floors made a tremendous improvement in the sound of the lower registers. I had the Thiel CS3.6 pair when I moved into this house and they just didn't seem to be enough for this large room. When I got the CS6 pair the sound filled in nicely. I'm not trying to play at loud volumes, just that the larger speakers seem to fill the range better in a larger room. The converse is true too- smaller speakers work better in a smaller room.
Everyone has a different path to take in this hobby. Many are happy to have the mid-range magic of Quads, which I also used to enjoy immensely at a friend's house years ago with female vocals, and others want the full range to go with their broad stage orchestral music and others the hard kick and punch of rock and roll.

One of the things that bothered me most about early digital recordings (actually, until very recently) was not the harshness, brightness or grain, it was the very obvious (to me) sense that there was a frequency extension ceiling above the music; that the upper harmonic extension simply came to a screeching halt; technically speaking, around 21KHz. Some would argue that we can't hear above that range. Well we can argue that one forever, but wether it is the absence of harmonics above that range, or the effect that this absence has on lower audible frequencies doesn't matter, it is audible either way. I hear a similar effect at the bottom end of the spectrum. Wether it is the ambience cues that we hear/sense, or undertones, or whatever, when the speaker is incapable of reaching into the lowest octave there is an audible low frequency ceiling (floor?), where just as with the high frequency ceiling, things come to a halt and one hears/senses the absence of limitless extension even if there is no musical content in that frequency range. All this compared to the sound of live music, of course; not just in a hall, but also what one hears in a studio.