SVS Subwoofer Isolation feet. Will I lose bass?


Most of what I see about subwoofer isolation has to do with minimizing rattles or bothering the neighbors.  But what about a sealed subwoofer on a concrete slab?  Would these dampeners not "dampen" the bass as well?

My setup...  Dual SVS SB16s on a concrete slab.  I don't have a rattle problem and the room is 20ft tall so I can't afford to "lose" bass because of my shakey rubbery feet.  

I've read and seen many great things about these but I have a hunch it would hurt a sealed sub on a slab more than help.

dtximages

twoleftears
I don’t see why a gizmo designed to impede the *transmission* of bass frequencies would necessarily dampen those frequencies in the room in which they’re being generated. After all, there’s a big difference between the subwoofer’s feet and its driver(s).

>>The gizmos don’t dampen the frequencies generated into the room by the speakers. If anything they increase them, by making the speakers perform more efficiently. That’s one reason everything should be isolated. Isolation of electronics is a two way 🔛 street. It blocks floor generated vibration AND reduces vibration on the “top plate” of the isolator, including airborne vibration. It’s two, two mints in one! 🤗
Springs are the way to go. All the talk about the springs in this post is all true. I looked at the Gia twos and I was disappointed but there’s no springs in those it’s like ball bearings and rubber layers. You’re welcome for the scientific explanation. LOL I install these on my sub woofers and my regular speakers. It’s been about a year and they’ve done a great job. As soon as I install them I noticed the difference that all the rattles in my room were gone. I’m not gonna tell you that the soundstage was bigger and blah blah blah, But they were doing a lot of isolation because as the volume went up the rattles became more frequent and now as loud as I can listen to it which is beyond comfortable there are no more rattles. Before I install these I drilled a larger hole in The bottom foot to allow me to screw them into the threaded inserts of where the original feet were. Each foot supports between 30 to 40 pounds. Here’s the link.

https://www.amazon.com/Nobsound-Aluminum-Speakers-Isolation-Amplifiers/dp/B07K9ZYP84#HLCXComparisonW...
Talking about the benefits of component or general isolation is not the topic here..

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.  


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.