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.
Unless you've invented anti-gravity there's no such thing as isolation. What we have instead is vibration control. And you're right, shakey rubbery feet will damp vibration, sucking up energy and causing you to lose bass.
Not very much however. Most all of these things work great because they work at midrange to treble frequencies where the ear is extremely sensitive even to micro-amplitude effects. All you have to do is squish one to see the most you can compress it is a very small amount. Its measured in hundredths of an inch. Then you look at the amplitude swing of a woofer, its measured in inches. You don't have to be a rocket surgeon to know they're not gonna have a whole lot of effect on a sub, one way or anther.
Audiophiles however are not even up to the level of rocket surgery. So expect a lot of different answers.
I thought you promised to spend some time in the library, mc. By their nature springy iso stands ARE anti-gravity devices. Hel-loo! The best performance for a sub would be place it on a set of springs. Awesome bass! Goes lower and more dynamics. You can forget everything else.
I added the SVS feet under my 3 subs on a tile over slab floor. I had a problem with things on the walls and shelves rattling when the lowest notes were played at moderate volume. The feet solved that problem. Whatever the reduction in bass was is offset by less rattles and more definition in the bass.
There's a YouTube vid I watched from a guy last night who did some measurements but I wasn't quite convinced I understood what he was saying.. He has a PB4000 (ported).. Ran REW both ported and sealed with the SVS feet. According to the chart, it appeared (again I'm not sure what I saw because it was like 2am) that they made almost no measureable difference while ported, but significant decline in output when sealed.
When he explained it, it made sense given theres much less cabinet pressure to move when ported.
The primary reason to isolate the subwoofer is to eliminate mechanical feedback to the system via the floor. The secondary reason is to reduce subwoofer cabinet resonance. It’s two, two mints in one! 🤗
geoffkait, I understand that. But if you have a sealed sub on a slab, wouldn't the "wobblyness" be counteractive to the woofer? Lessening its effectiveness? Lowering its output?
According that dudes youtube vid, that's exactly what happened I think! But I have not heard others say this is an issue.
I figured, surely, someone has first hand knowledge of the effectiveness of these feet, or Auralic Subdude on their sealed slab-sitting sub.
No. The (appropriate) springs have very high lateral stability for subwoofers, as we say in the trade. Stiffness to any civilians out there. No wobbling.
geoffkait, I understand that. But if you have a sealed sub on a slab, wouldn’t the "wobblyness" be counteractive to the woofer?
Yes. Exactly.
One thing you need to understand, you are taking advice from a self-proclaimed theoretical physicist, who designs interstellar rocket propulsion thrusters in his spare time and has a website devoted to flying saucers. His most impressive accomplishment is consistency: 21k posts, and not a one of them worth reading. Irrelevance on such a scale is remarkable even among audiophiles.
I would post a link to his website, but every time I do he has it removed. He likes to mislead and insult, but never inform, and at the same time loves to sell the unsuspecting who stumble onto his flying saucer website. So you will have to search him out and find machina dynamica on your own. Then ask yourself how much time and effort you want to put into pursuing the advice of such a one.
Isolation feet are not needed here and could be detrimental.
It probably won't hurt you as much as it would smaller speakers. The idea is that you want the speaker to be rigidly fixed in all three dimensions without rocking. The woofer's apply a great deal of energy against the cabinet. Even light rocking can reduce the output into the room.
You do want to prevent transmission from the cabinet to the floor, and create a vibration signal that reaches you at a different time than the acoustic one.
Thousands of audiophiles isolate their speakers and subs with spring-based iso devices. And guess what, they ain’t amateurs. This isn’t the 1980s any more, guys. Wake up and smell the coffee! ☕️
It's been said here perhaps hundreds of time: watch the Townshend Audio YouTube videos wherein Max Townshend demonstrates the effects of installing a set of his Seismic Speaker Podiums between a loudspeaker cabinet and the concrete floor they are sitting on. THEN ask questions.
Actually the speakers move more without isolation. The very low frequency seismic type forces are causing the entire building to rock back and forth. The idea that speakers rock back and forth on springs or wobble is a f-f-fallacy. It’s the opposite. That’s the whole point of isolating anything. Hel-loo! That’s why electron microscopes are isolated on spring systems, so they won’t move whilst photos are taken of the sample. It’s a mass-on-spring SYSTEM. It’s not rocket science, guys. 🚀 That’s how they were able to detect gravity waves with the amplitude of an atomic nucleus - by isolating the optics and electronics so they wouldn’t move.
It might not be obvious to the casual observer 👀 but there is a limit to how big and heavy speakers can be due to center of gravity issues. BUT those limitations don’t apply to subwoofers which have relatively low centers of gravity. So, springs can go directly under the sub without all the rigamarole needed (a la Townshend Iso device) to get the springs in a wide pattern so the speaker will be stable.
@bdp24 This is a video done by Townshed to promote their product right? Have there been any/many independent users to cite similar experiences? I've seen tons of great things on Isoacoustics and have a pair of Gaia II's (not installed yet).
My question is mainly for the effect of a large sealed subwoofer on a concrete slab. I would imagine, and some have agreed here, that the isolation feet would be detrimental to output in THIS situation.
Marvellous convincing video....I have a small before taste with my "imperfect" but effective method to couple- decouple homemade...On the bass and imaging results are speaking... My method of coupling-decoupling is not on par with these Townshend isolation pod but cost me 100 bucks compared to 1700 bucks... :)
Having the money I will buy one for refining results with non perceptible vibrations....Even coupling-decoupling homemade methods gives some results... I use sandwiched between each other 5 different properties materials...Imperfect yes, good yes....
In my experience these seismic vibrations(under perceptible level) greatly affect the sound like ANYTHING linked to the electrical grid or acoustical field of the room way more than an upgrade of gear in most cases...
Most people are unable to imagine these S.Q. amazing transformation when we work on the controlling aspects of these embeddings, be it mechanical like in the Townshend example, or electrical, or acoustical; called all that "snake oil or placebos", like men of the past were calling "gods" strange visitors from the sky...Man need to understand and the simple way is to give a name: god or placebos,or snake oil etc... It is way more simple to name it than to try it with experiment... :)
This is one of the thing underestimated by us all....
Sorry to disappoint but unless you are isolating with spring type devices you’re not blocking seismic vibrations. The very low frequency seismic type vibrations 0 to 20 Hz can ONLY be blocked or attenuated by decoupling - mass-on-spring isolation. I apologize for having to be the one to tell you. 😢 Your isolation club credit card has been declined. - Regards, the management.
Sorry to disappoint but unless you are isolation with spring type devices you’re not blocking seismic vibrations.
Nothing to be sorry...
If you would have read my post you would have read the word: imperfect, not on par, a before taste, and also my wish to BUY this isolation pod...
I only wanted to gives my impression about the necessity to controls vibrations....
This is very important that’s all...
But I know how you like to own a last word.... then be glad....:)
To your discharge I learn only one thing in my life: it is how to read....I am a man of no gift except that one...And to know how to read implicate to search for the true INTENT of the writer, not only the translation of letters in sound....My intention was to confirm what I learn from this video ...
" You are one neuron short for winning this synapse argument tough" Groucho Marx
The funny thing is if you weren’t so “cheap minded” you could have correctly isolated your entire system for what you paid for your homemade devices. Do you see the humor? 😀
Cheapness is not a virtue all of the time. - Pee-wee Herman
The funny thing is if you weren’t so “cheap minded” you could have correctly isolated your entire system for what you paid for your homemade devices. Do you see the humor? 😀
Another free judgement...
I know perfectly well that using springs will be better...( I am not an idiot 7 days on 7)
I wait for my house sale to recreate my system....it is not possible now with my actual desk...And my actual S.Q. is bearable to say the least...
And you must know that being creative is not synonymus with cheap minded...
You begin to resemble someone I know... :)
" Cheap? you said....What do you want to sell me?" Groucho Marx
What is comical is my post was an acknowledgement of your own post.... Did you miss an enemy?
But I know how you like to argue....Myself too, but only when people are of good faith or humorous.... You are at least one of these 2, times to times... :)
you could have correctly isolated your entire system for what you paid for your homemade devices
The amount I paid for ALL my homemade solutions was 2/3 of the amount I will pay for these isolations pods...
But I also invest to controls my electrical grid and the acoustical field of my room …. All that for 2/3 of this money....
The most costly device I bought cost me 50 dollars (usb S.G. from hong Kong) after that shungite etc
Then for a fraction of the price I develop intervention in all 3 embeddings controlled fields...Then even if my mechanical isolation are not perfect they work great...I will recreate my system better in a year or 2 in an another house...( with spring under quartz bed for the speakers)
The acoustical field mods. are the more impactful of the 3 set of solutions for the embeddings.... :)
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).
In a word the audio system, sub-woofer included, when music play, are not a mass of separated parts no more; they are ONE totally integrated and linked system, mechanically, electrically and acoustically in your room...All parts and field interacted and participated in the recreation of the musical sound in your ears... And sometimes your brain will observed an improvement, coming from one of these 3 dimensions and improving simultaneously the dimension of perception linked also to an another one of the 3 and sometimes even the 2 others....
This is my experience....Someone more knowledgeable will explain better the details...It is very easy to verify with simple modifications...
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.
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.
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… :)
Let me clarify what I was thinking about driver/cabinet motion.
The combination of small footprint, light weight, and distance from the floor are what make this issue most prominent. If you have smallish stand-mounted monitors I encourage you to try some weight on top and listen.
Would it happen with a big heavy woofer, inches from the floor? Probably not nearly as much, but I certainly don't want it spring loaded to the floor any more than necessary.
My speakers actually were loaded with 70 pounds on each, and this was good... I will try someday juste the springs compared to the speakers loaded with weigh on my sandwiches....The weigh gives some damping, and the different densities materials I use give some coupling-decoupling but also some tuning.... I will compare someday with the springs with a bed of quartz....
So....i have an SVS SB16 and have it on a carpeted floor. Tried it without feet and the bass was bloated. The SVS feet helped tighten things up with not a significant loss. I then went to isoacoustic Gaia II with carpet spikes and everything is significantly tighter/cleaner than the SVS but you lose some of the chest rattle.
My vote would be: If your looking for musicality the isoacoustic is the way to go. Dual purpose for music and theater the SVS feet are fine and enough of an improvement to atleast compensate for moderate cost.
Good illustration of how carpets act as springs. Two spring systems one on top of the other is bad news. It’s like driving down the road in a car with two springs one on top of the other for each wheel.. It will be a very b-b-bumpy ride.
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