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.
I run 2 SVS SB16Ultras and 2 SVS PB13Ultras. All are on the SVS isolation feet. Theater is on the second floor so I'm not on concrete but I did not lose any low end and as mentioned before the sound tightened up. Not to mention I run these subs at a gain of -24 and can still rattle light fixtures, doors, etc.... if wanted. With SVS typically if you lose some bass you have plenty of gain headroom.
I also have the Townshend platforms under Focal Utopia Maestro towers. I have no idea how the springs in these things are engineered but they are game changers.
@pmg1223, in one of the Townshend Audio YouTube videos, Max explains the design and demonstrates the effectiveness of his Seismic isolator. Just do a search for the company name on YouTube, and all the videos will be made available for viewing.
bdp24 @pmg1223, in one of the Townshend Audio YouTube videos, Max explains the design and demonstrates the effectiveness of his Seismic isolator. Just do a search for the company name on YouTube, and all the videos will be made available for viewing.
>>>>The Townshend video answering the questions inherent in the OP was posted yesterday morning at 10:14 by your friend and humble scribe.
Thanks for the real-world experience and with the same sub! That's kinda was I was suspecting. I don't like hearing the loss in "chest rattle" as that's why we buy big subs in the first place. But if the quality is that much more significant then perhaps it's worth it.
I really cringe at buying MORE Gaias for my subs too though.. That's $1200 in isolation for me :(
Actually Geoff, the video to which I’m referring is a different one. It is entitled "The effect of ground vibration on audio systems", and was taped in a private space (maybe at the Townshend facilities?). It starts with Max discussing the problem, then moving on to possible solutions.
He is shown standing behind a table (and in front of a projector screen, used in his presentation), on top of which he demonstrates different forms of "mass on spring" isolation. He demonstrates the differences between spikes, a plain spring, and his Seismic Pod (which contains the same spring). He covers the issue of the undamped movement of the plain spring vs. the damped behaviour of the Pod.
Ack-chew-ally the video I posted was actually more to the point concerning cement floors. Yours was good too. 😬 As I previously pointed out damping the springs hurts the isolation and - more importantly - is audible. 😩 The video I posted also shows that damping the speakers or mass loading is not necessary once the speakers are isolated.
The missing “chest rattle” people report is the lack of boom and distortion when the sub is properly isolated. Key word: properly. When a speaker or sub is properly isolated the bass frequencies are lower and more articulated with more slam. Everything is better and it’s the same for any speaker. Hel-loo! What’s the hang up? Talk amongst yourselves. Smoke if ya got em.
@geoffkait then how do you explain significantly less db at 20hz - 80 hz? That's not "better" it's just quieter. So of course there's less perceived boominess and distortion.
Check out the video that shows his testing and measurements with/without feet as well as ported vs sealed..
I think I will go if I want to stay with homemade solution with my sandwiches of different materials: quartz feet+granite plate+sorbothane+granite plate+corkplate+bamboo plate, but I will add a quartz sand bed in a bamboo box under the speakers and on top of this sandwich....I will use a mix of quartz sand with 2 different size for the sand peebles...
I cannot design a "damped" system of springs adequately myself to controls resonance....The explanation why is in the video...The price to afford them exceed my purse....And it is more fun to recreate, invent, and experiment ourselves....
I think the quartz bed will controls some resonance too....Perhaps not like a damped springs system but surely approximating it, quartz sand+small peebles will dissipate vibrations resulting from resonance in heat and it is more simple to make for me....
Only with my loaded(70 pounds on each one) speakers and the sandwich I had already now give me good results....The quartz bed will help with resonance better than only the sandwich....
dtximages OP @geoffkait then how do you explain significantly less db at 20hz - 80 hz? That’s not "better" it’s just quieter. So of course there’s less perceived boominess and distortion.
>>>>I prefer not to try to explain things that don’t make sense. What would be the point?
my experience soft vs rigid is similar to the video. the best sound achieved on my carpet over concrete floor is when the spikes pierce the carpet and make contact with the solid floor, speakers and subwoofer.
I already explained why carpets are bad Gnus. 🐃 🐃 Besides, this discussion is really about isolation vs spiked or soft, not spiked vs soft. If the SVD isolation feet are some kind of rubber they aren’t providing real isolation, anyway. A lot of companys call their feet isolation feet but they are really dampers of some sort. What I call real isolation is mass on spring devices, you know, air springs, air bladders, even squash balls, inner tubes, but especially steel springs. So, in that light I’m not surprised by the YouTube test. I would not say SVS are comparable to real isolation devices. Get real.
I think some people are too smart for their own good and too dumb to know it.
1. The SVS Isolation feet are basically the same as squash balls or any other type of rubber device that limits the transmission of energy into the floor.
2. This conversation is NOT about spikes, it's about isolation feet in a sealed sub on a slab floor and its effect... Detrimental to output? If so, do the positives outweigh the negative of less output?.. No theoretical bs about layers of quartz rocks.
3. Can you block someone from posting on a thread?
4. If I told geoffkait he's the smartest person in the room and gave him a cookie would he go away?
@dtximages I have an older pair of the SVS SB12-NSD subwoofers. My subs came with smallish rubber feet (I assume rubber) that keep them off the wood flooring. I would think yours did also. Are you just wanting larger ones?
As I mentioned mine work fine on wood flooring but would likely not on carpet.
To expound on the YT vid I mentioned, his measurements, if I remember correctly, showed almost no impact on a PORTED sub. There certainly is a difference in the way cabinets react to a moving woofer in a sealed cabinet with no air escape, so this seems to make sense.
If these feet are detrimental to a sealed sub, I wonder why i have not heard anyone mention it.
Could it be because we're all sheep and agree with our favorite poster or reviewer?
I know that MANY people have sealed subs and have sought after isolation.
@dtximages I was actually considered getting these for my subwoofers, not realizing that there were already feet on them.. I was just checking out the SVS website and if I understand their pricing correctly it looks like it only cost $49+shipping for a set of four. And there is a 45 day return period if not happy. Seems reasonable enough, especially compared to some other audio items.
I don't believe that demonstrating the reduction of acceleration of a speaker enclosure proves that it will improve the sound. First we have no indication of the amplitude of the vibration and acceleration. It could be inconsequential. Second we have no evidence to suggest that the amplitude of the acceleration is audible. The enclosure may already be sufficiently damped and braced as to make the vibration inaudible. Third is that the reduction of audible enclosure panel acceleation (if any) may make the sound quality less pleasing overall, especially if the manufacturer has tuned the resonance to augment the overall frequency response of the speaker. Reducing that may make the speaker sound thin and less balanced. There is a lot more to this than showing a display of zero acceleration.
I added the SVS isolation feet to my sealed SVS SB4000 subs a few months ago. I did not experience any noticeable change in output. The reduced db output in the video has nothing to do with the feet or the flooring, it is because the ports are being plugged. Plugging the ports on a ported sub will change the tuning of the cabinet and thusly its output.
@audiorusty My understanding of the video was it measured much higher plugged without isolation feet. Then much less with isolation feet.
He talks about why he thinks there was very little difference with/without feet unplugged... yet a significant difference sealed with/without feet.. So to be clear:
Open ports = almost no difference in stock vs Isolation feet Sealed = significant drop in db when using isolation feet
I'm using townshend speaker bars on my standmount speakers, on an oak floor on concrete. The stands are weighted with atacama atabites for a total mass including speakers of about 27kg each.
There is another set of 4 decoupling durometer pads on the top of the stands. The townshend are not cheap new price was about £900.
I always buy isolation devices 2nd hand and paid £400, figuring if they did nothing I can move them on. They are entirely positive in my experience, imaging is improved bass is cleaner.
For a front firing subwoofer I would expect improvements too for sure, for down firing sub , I can imagine things could be different but I wouldn't say they don't work without trying them first.
On my down firing REL transmission line subwoofer I replaced the stock feet with stillpoint ultra SS, I also again found improved imaging here weirdly but that might be about controlling vibrations into the rest of the room and system, or it could just be a harmonics thing, bass is cleaner.
Bang for buck these are low in my system but they are gains so I'm still very happy. I used to use spiked stands before.
Springs will allow the low frequency energy to pass through the path of least resistance = air. Springs will also tighten up the bass as well. *Obviously the correct tuned springs for the mass is required*
And for a very moderate investment into a bit of personal scientific research, I could not more highly recommend seismic isolation for the vibration makers in the room. It simply works, just as goeffkait states.
I thought that the test that showed the most deviation was when he used the packing foam as the mounting device.
It is my understanding that a ported cabinet is a tuned cabinet where the designer is using the cabinet vibrations and internal air pressure to help increase output and enable the sub to cycle lower. In the REW analysis, there appeared to be very little difference in output and low end extension with the three mounting methods (iso feet, packing foam, batteries) when the sub was in extended and standard modes. When the sub was in sealed mode there was very little difference between the iso feet and the batteries but a significant difference with the packing foam.
So my conclusion, though maybe incorrect is that the iso feet aren't doing a lot, at least on a concrete slab, and that the port plugs and the packing foam are changing the tuning of the cabinet in a way that reduces output and low end extension.
I believe that he did not run the test with the stock feet.
Test 1 - Iso Feet Test 2- Packing foam Test 3 - Batteries (ridged)
to the OP, as with anything your mileage may vary, so I'd recommend finding a low cost way to test this if you are interested in how sub isolation might affect your sound. Either find a place to buy with a return policy or buy them used at a price you can then resell at.
I'm using isoacoustics feet on my Martin Logan towers to good effect (and well worth the $) but when I tried using similar isoacoustic pucks under my ML sealed subs, I found they made the subs sound horrible. I actually thought I had a woofer that had gone bad as I was getting audible distortion from them. I removed the pucks and the sound returned to normal.
I don't have a detailed explanation as to what caused these particular subs to react so negatively to this particular product in my room, but suffice to say that these types of products can impact the sound and sometimes that change will be positive and sometimes it will be negative. I think you just have to try and let your ears tell you whether the change was better or not for you.
But Geoff....If a second "Spring System", applied to the vertical plane isn't identical to the first. And in fact is designed to augment the first in a resistive fashion. (By design, tuned for a different cyclic wave range, with also a transduction medium utilized between layers, "Each a discrete (compartment), in a multi-layered architecture". So that instead of the way that a spring usually and inherently utilizes as it's means of kinetic dispersion, it cannot interfere with the other system involved). Would that not be beneficial? It would only be detrimental if the range of each spring "System", indeed "Crossed" by a fair amount. (>.007%). Which could also cause odd harmonic resonance. This will also increase the efficiency of the spring in the 8.32Hz-50KHz range. "Funny how it seems to begin at the "Schumann", resonance"! This is only, "Of course" in a multi-layered, Constrained layer system. And um...Using a certain alloy of brass which has been in fact, (Cast) in the springs construction seems to help "ALLOT". I also still have a few of the, "links" to a few of the studies done on the specifics of this. In case anyone would like to peruse them. Hee hee, But I'll warn you now, they are quite the exhaustive read!
One more thing I have noticed in experiments with "Constrained layer damping" systems. And this is a bit weird! But interesting all the same. Everyone knows that three points make a perfect plane. And you must have at least three to make any "plane". Also that anytime more than three are used? You may ONLY make an "Imperfect Plane". And of course we all know that, No- "Perfect Plane", can exist even in theory, with more than three points. Basic physics, and at it's most easily defined, understood and excepted level right? Where this got interesting was in my plotting though "Cymatic" figures for vibration analysis. While, "Transitioning known quantities of specific vibration through differing transduction devices/systems/materials as accurately as possible was the goal". This for a "Baseline". {{Why? Because, If I do not make it? I will never be able to have the fun of figuring out how to break it.}} Also It should improve the sound of any system tuned for where applied. Anyway, The goal being- So that on each side of the equation? The, "Cymatic", physical representation plotted with the same equipment should at least, "Resemble" that of the other side. Just a difference in amplitude if done correctly. Fairly simple right? But while using these springs. "Yeah, I am going to blame this all on Geoff! I wasn't much on springs until that kernel was placed there by Geoff. I had an idea coalesce from something I had recently read in another's notes. "He has long since passed and I do not think would mind".
"As we look at the six original Solfeggio frequencies, using the Pythagorean method, we find the base or root vibrational numbers are 3, 6, & 9. (AND)-. Nikola Tesla tells us, and I quote: "If you only knew the magnificence of the 3, 6 and 9, then you would have a key to the universe."
And so, simply because I could. I figured "WTH", and why not. Using only sets of three, for each plane. As the only points on each level of three layers. And this in a symmetrically balanced, vertical structure, that of a three layer system? After all of that? It just wouldn't work! Well, not until I applied a voltage..... Then it became a "Polarized system".
My Nirvana Platform is a dual layer heavy masses on springs system that employs a second mass-on-spring system on top of the first mass-on-spring system. But the two systems would interfere unless their individual resonant frequencies Fr can be separated by X number of Hz. It would be like driving down the road with a double identical springs in series for each wheel. It would be a very rough and chaotic ride. For heavy masses I use 2” thick bluestone slabs that are around 25 lbs each and my cryo’d springs. If you do it right you can get down below 1 Hz with ease. This one of the isolation concepts employed by LIGO project to detect gravity waves.
OP, just to mention again, I believe the SVS feet are only $49 for a set of 4 (verify with them), with 45 day return period. Shoot, for that little I would pull the trigger to see if it suits my fancy before investing in the high priced spread.
Though 3 points do indeed define a plane, springs don’t care about that. They are more concerned with mass stabilization. I have found 4 springs to in general be much more stable than 3.
Your "Nirvana" platform? Geesh! You name your platforms! That's a fair amount of mass per layer. I use about half that. But then' There is simply NO substitute for mass when it is needed. Hm, Maybe I'll name my next one too. "Bob"? Hmmm. Chuck? maybe..
BDP? Have you tried "five"? I heard about a fellow out west, whom tried "Six", once. But there was some kind of accident.....
The Mana from U.K. employed a great many glass shelves. The more the better so they said. Nirvana dual layer platform is a product. Hence the naming of it. But everyone knew it as Nancy. Building more than two heavy mass-on-springs layers wouldn’t work. It would be very unstable. The idea is to construct one dual layer device the right way. Sub Hertz performance. Hel-loo!
I am a newbie to this forum. Why are people arguing and fighting on here? I thought it was meant to be to help and advise each other in a kind and considerate way. Oh well.
@dyson2004 it's because everyone is suspicious of snake oil and people have different opinions. The consensus here is:
the SVS feet will relieve vibration in walls and downstairs. But on a concrete slab they probably do nothing positive for the bass. Most of the responses here are about their performance on second floors where the sub shakes the whole house.
I have a brand new SVS PB 2000 Pro married to a pair of JBL L100 Classic speakers. I tried the SVS special footers and found my sub lost its magic. If anyone wants to purchase, the first $25.00 plus shipping cost shipped to your door. In my room, they took away some of the magic.
The OP perhaps has moved on from this thread but in case it helps anybody else. I bought these feet last week and it helped a great deal with my second floor home theatre rattle. Same observation as dtximages above.
I'm the OP. I'm sure it does help on the second floor.. But the post was the effect the feet would have on a concrete slab solid floor. Not on a second or elevated floor.
If you're on the second floor, I'd like to know the difference between using the feet and just turning down the volume because that's essentially what these do.
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