SVS Subwoofer Isolation feet. Will I lose bass?

It doesn’t make sense and if it doesn’t make sense it’s probably not true. Now if the sound was less boomy, which one would expect, maybe the guy interpreted that as less output. Who knows?

I go back to where a guy on YT did an experiment with the SVS rubber Isolation feet on his sub in sealed mode on a concrete slab and the output was significantly less when measured with a mic.

Right. Makes perfect sense.

Anything squishy, be it rubber or spring, ball or whatever, the energy from the driver will cause it to compress. Once compressed it is going to expand. This compression and subsequent expansion occurs, to some degree, in every material. Every material does this at its own particular rates, and these rates vary according to frequency and amplitude for each material.

So what happens when you put squishy stuff like springs or rubber rings under something like a speaker? Well, what happens depends on the frequency and amplitude we’re talking about. Its not like its all the same across the board.

Something like a metal spring, no damping, this is going to bounce up and down at whatever resonant frequency. What this means is sometimes at one frequency the spring will completely suck the energy out of the system, while at other times it can resonate and increase output. This is just basic physics. Same thing happens with the rubber feet, the difference being the harmonic frequency and degree of damping, if any. It may well be the SVS is fairly highly damped. In that case it would not resonate, not to anywhere near the same degree, and so there would be no frequency where it would add to output. There would only be frequencies where it subtracts.

So now you have one totally sensible and science based way of explaining the measured output observation.

One. There’s another. These things look to be pretty thick. Boundary wall reinforcement is greater closer to the floor or wall. Raised up off the floor, even a little, less reinforcement, less bass output.

So now you have two perfectly sensible science based explanations of the observed measurements.

How odd Audiogon’s reigning theoretical physicist wasn’t able to think of either one. Huh. And his system is... oh, that’s right, he doesn’t have one.

Huffing Clorox again, mc? 

It’s par for the course to have more bass than is actually on the recording. Hel-loo! But this is not the 1980s, guys, mc apparently thinks it is.

I must wait to sell my house but I cannot wait to experiment with my speakers and add to my sandwich of 5 different materials under them 4 springs and directly under the speakers a bed of quartz sand/ small peebles. The sandwich between them....

I trust the springs to isolate from external vibrations, and for the quartz bed to manage gently internal resonance with the sandwiche… :)