Bass Response and concrete floors

Abstract7: I would agree that bare concrete is suboptimal from an overall acoustics point of view. However, most concrete floors in homes or studios are going to be padded and carpeted, or covered directly with wood flooring without a subfloor (as mine are). Both these coverings work well. What is being disucssed here is the physical resonance of a suspended floor and the severe damage to frequency response and transient response that accompanies that resonance. There isn't a good-sounding studio in the world that has a flimsy, flexible floor. The huge advantage of concrete pads is that they drain the physical vibration of the loudspeaker cabinet into the ground, and prevent it from causing physical resonance of the floor/walls/ceiling. And that is all we're saying here. The reverberation characteristics of the room are a very important issue, but one that is totally separate from the issue of eliminating loudspeaker-driven, structure-borne vibration and resonance.

It is unfortunately little understood that the physical coupling between loudspeaker and floor can transmit MANY times greater sound energy into the structure than you could EVER achieve through airborne sound transmission. And if it isn't drained into the ground, it's going to reradiate from the structure back into the room. IMO, it is the job of the playback system and listening room to give you what is on the recording in as pure and noncolored a fashion as possible, and the only way to do this is to keep the room from literally being a sound source of its own.

Cant say I'm an expert here, but I recently moved, and have my system on concrete floors/walls. I have placed the boxes to my equipment behind my gear (hidden behind a very large tapestry), I have 2 squares of carpet under each main speaker, and finally some homemade sound panels directly behind each main. I am happy with the response from my mains, and think the bass is damn good. I'm sure every room is different, and equipment acts differenly in each room...but hey, if a salesman wants to actually sell you a less expensive piece, I'd say try it...worse case, exchange for the higher end piece.

Also, my speakers are on spikes...After reading a few other responses, I feel this is important to note!!

I have Vandersteen Fives in a room with a concrete floor partially covered with padded carpet) and the bass is exceptional. The sheetrock walls are judiciously treated with Ecco Tunes and RPG panels. Last night I was recalibrating the Vandy Five subwoofers and using the Radio Shack sound meter (and making adjustments for its non-linearity in the lower registers) measured reasonably smooth response down to 25 hz with a respectable reading at 20 hz.