Why Does A Concrete Floor/Spiked Metal Rack...


suck all the warmth and life out of my system?

I have been thoroughly dissatisfied with my hi-fi system for the good part of a year now and I have been unable to until recently to put my finger on the problem. In a nutshell, almost every CD I would play would sound bright and harsh and bass light. The top end and upper midrange would completely overwhelm the bottom end. I have experimented with all sorts of tweaks and in particular various isolation devices, and although I was able to achieve minor changes to the tone the overall top end brightness and lack of bass was still evident.

I was enjoying (as best as I could given the problem!) a listening session and wracking my brain (for the ten millionth time) for ideas on how to make my system work better, when it suddenly dawned on me that I had these small plastic/hard rubber? cups that might be ideal to place under the rack spikes as a last ditch attempt to solve the brightness issue. With the music still playing I carefully tilted the rack enough to slip the cups under each spike on the four corners of the rack, thus de-coupling the rack from the concrete floor. They were a perfect fit and the effect was both immediate and DRAMATIC. The system was for the first time tonally balanced, the bass response increased, the sound stage widened, the noise floor dropped, there was greater depth, increased clarity, and most importantly the brightness and harshness had completely disappeared!

I was firmly of the belief that audio racks should be coupled to the floor for stability and assist with the reduction of floor vibration eminating from the floor. My rack is a rigid design composed of tubular steel and every cavity is filled with sand in order to reduce any possible ringing. The rack is supported by four large adjustable screw in spikes which penetrate the carpet and couple the rack to the concrete floor beneath. The components are supported on MDF shelving. What I discovered this weekend is that this rack/floor interface was completely sucking the life out of the system. Upper midrange and top end frequencies were being accentuated at the expense of the lower mid range and bottom end, thus producing the fatiguing brightness and harshness.

Can anybody explain to me in laymans terms why this occurs?
unhalfbricking
Should we pressurise the tubes with air or nitrogen? I am sure that the choice of gas will affect the sound also! Seriously, pressurising the tubes won't change the rigidity of the structure, but will add to the mass (slightly) due to the added gas.
impep_whatever...Yes, the pressure will stiffen up the tubes by prestressing the steel. I think that high performance racing bicycles have pressurized frames. It permits the use of lighter tubing, and for those bikes every ounce counts.

By the way, use nitrogen. Nitrogen is a byproduct of oxygen production (they distil liquid air) so it is inherently a completely dry gas, and quite inexpensive because you get lots of it when you make liquid oxygen. Co2 would work also. The main thing is don't use air because the oxygen could cause corrosion.
If you were to cyro the support rods and the internal conductors and the Micro Bearing fill and the shelves and the Audiopoints you would be coupled even more closely to the music....Align the molecules. The most direct coupled high speed resonance transfer device this would surely be..Would the addition of sorbothane or rubber make it slower or faster or just totally destroy the whole high speed connection?....Tom