There seems to be a fundamental difference of opinion between those who would couple their speakers to the floor (e.g., with spikes), and those who would decouple them (e.g., with springs). I’ve gone both ways, but have found that I prefer the latter; I’ve currently got Sorbothane feet attached to my tower speakers, so that they wobble or "float"—much like the Townshend Platforms videos show for that similar, but more expensive, approach. My ears are the final arbiters of my listening experience, so they rule my choices. But my mind likes to have a theoretical explanation to account for my subjective preferences.
That’s where the question comes in. A very knowledgable audiophile friend insists that what I prefer is precisely the opposite of what is best: that ideally, the speaker enclosure should be as rigid and immovable as possible so that the moving cones of the drivers can both most efficiently and most accurately create a sound front free of the inevitable colorations that would come from fighting against a moving cabinet. He says that transients will be muddied by the motion of the cabinet set up by the motion of the speaker cones. And this makes perfect sense to me in terms of my physical intuitions. It’s perhaps analogous to the desirability of having a rigid frame in a high-performance vehicle, which allows the engineers to design the suspension without having to worry too much about the complex interactions with a flexing chassis.
Am I just deluded, then, in preferring a non-rigid interface between speaker and floor? Or does it depend on the kind of floor? (I get that most advice seems to favor decoupling from a suspended wood floor, and coupling to a slab; my floor is hardwood, but not exactly "suspended" as the underflooring structure is very rigid.) Or are there trade offs here, as there usually are in such options: do I gain something (but what, and how?) even as I lose something else (i.e., clean transients, especially in bass tones)?
The ears will win this contest, but I like to have my mind on board if possible. So thanks for any input you may have on this question.
I do agree that you want the speaker to be unable to move back and forth, but the total answer is complicated.
Big feet may prevent the rocking against the woofer motors. Floor standers with woofers close to the floor have less of this problem.
Soft feet may make transmission through the floor less likely.
The worst thing you can do IMHO is to rest an entire speaker surface against the floor. Everything else is probably going the right way.
I just had the very unusual experience of "hearing" my kittie purring through the floor. She was resting on the carpetted floor, about 6" from the front leg of the couch and if I rested my head on the pillow of the couch I could hear her. So sound travels a lot more through the floor and other surfaces than we realize.
Springs will wobble if pushed at frequencies much lower to what the speaker is generating such that, at audio frequencies, they are as stable as they would be on spikes.
I had always thought that the best possible situation was spikes thru the carpet into the concrete ( at my house) floor. With a LOT of urging, one evening I removed the spikes and replaced them with the GAIA feet from IsoAcoustics and realized that my preconceived notion was wrong. Bass was more pitch accurate and mid-range smear that I was unaware of was suddenly gone. These are rather large floor-standers (110 pounds each). I have no clue as to why the GAIA's make such an improvement over spikes, but they certainly do and are worth the time/effort to try. I have no affiliation with the manufacturer or distributor.
I agree with Eric, it is complicated and floor does transfer sound. I tried to couple (spikes) and decouple (Vibrapods) and cannot say one way is better than another - just different sound. I moved recently from wooden floor/basement home to one on the slab with ceramic tiles and resonances are completely gone, but it might be caused by different dimensions of the room as well - back wall 2x further away (less of the room effect at bass frequencies). Vibrapods and such make speaker less stable - important with kids. Spikes over large/wide granite slab on isolation (like Vibrapods) might work well. They also sell in gardening stores, heavy as hell, garden concrete columns/pedestals - very cheap and way better than stands (if you need them), as long as you can tolerate such atrocity in your room.
Thanks folks. But my question was more theoretical than practical: as far as practice goes, I’m sure my system sounds better with the speakers decoupled on Sorbothane feet. But the theoretical question remains: WHY? It would seem, as my "expert" friend argues, that a rigid structure for the drivers would be better. It makes intuitive sense that the motion of the speaker cones will necessarily move the entire speaker enclosure on that "floating" platform, even if in only very tiny amounts. This—again, it would seem—should "smear" transients, especially at lower frequencies, which should result in a subjective experience of reduced clarity, locational specificity, and so forth.
Only Eric has addressed this, and he only very briefly. That having woofers closer to the floor would be better is consistent with my intuition here: the moment of inertia on a tall tower (49"), if the woofer(s) are mounted high, will be greater, and thus the movement imparted to the enclosure will be greater. As it happens, my speakers employ the "D’Appolito" array: two 6.5" woofers, one above and one below a dome tweeter, all three of them at the top of the tower. And yet, the speakers DO NOT sound smeared or compromised when standing on rubber. Why not?
If you search back, you will find about 101 posts on this topic and many answers to wade through that both support and refute the benefits of decoupling. Folks around here have been decoupling speakers with things like hockey pucks well before the more recent craze of decoupling products became available. To your question about a "theoretical explanation" I have linked videos from manufacturers Townshend and Credo, as well as an article on IsoAcoustics Frequency Response Testing at the National Research Council of Canada, and a thread posted about springs on the dreaded Audio Science Review. I hope this helps - draw your own conclusions, and good luck convincing your "very knowledgable audiophile friend"!
Did you surmise your speaker cabinets were moving or did you see them moving?
I would guess the Sorbothane is providing some absorption (reducing the transmitted energy) as well as lowering the frequency seen between the cabinet enclosure and the floor. I can’t comment on how that equates to a difference in perceived sound when compared to spikes as I’ve never used them.
My speakers are roughly 4.5’ tall- I use the rubber feet that came with them and the floor is Saltillo tile on concrete slab. I’ve never noticed a speaker cabinet moving regardless of the listening level.
From the latest I've heard and been told the biggest problem is microphonics in our systems. It's amazing how the sound of electronics are literally changed by vibrations. And the largest source of vibrations is our speakers and coupling seems to be the best way to send vibrations from our speakers back into our systems. You can isolate each piece of gear but that seems to be putting the cart before the horse. So at this point after years of coupling(I did the first Stereophile review of speaker cones) I believe I have switched camps.
I went from coupling to decoupling big time. I guess a lot depends on the construction and acoustic treatment of your room. In mine, fully acoustically treated with concrete flooring, coupling ended up resulting in too bright a sound. Now using thick maple boards with the spikes resting on metal coin like bases placed on top of thick soborthane hemispheres. Much easier on my ears, like tube vs. ss sound. The best part of that setup is I can adjust the speakers angles by simply sliding the maple boards around on top of the carpet. As the PBN Montana XPS weigh 214 lbs each, it's a wonderful setup.
My speakers are on a second floor suspended wood floor. I decouple. On a concrete basement slab, I think I would couple. It's not very often that we successfully go against our preconceived notions.
Snilf, you are not deluded, and your friend (and anyone else lauding coupling) is misunderstanding the big picture. Yes in theory, in the perfect world of imagination (utopia, literally “nowhere”) then being fixed and unmoving is the way to go.
Only problem, we live in the real world. In the real world when the speaker cone moves one way the speaker cabinet moves the other. The result is not what the couplers would have you believe, robbing the music of dynamics and detail. The mass of the cabinet is so much greater than the moving mass of the cone and coil this might as well be zero.
What happens instead is the vibrations from the driver propagate out from the baffle, around the sides and back, down into the floor. Vibrations never just flow like water in one direction. Agitate some water and see. Waves travel out until they hit something and reflect back. If this was just the speaker floating in space that would be the end of the story. Very quickly the cabinet (which is specifically designed to dissipate and end vibrations) would stop vibrating.
But the speaker is on the floor and so sets the floor to vibrating. Unlike the speakers the floor is not designed to be nonresonant. So now the floor is vibrating. The speaker is on the floor. Speaker and floor are a resonant system. Floor is connected to walls, walls to ceiling. In no time flat everything in the room is vibrating. All because you played some music.
That’s with speaker coupled to floor. Speaker isolated from floor, now stops much faster. Where coupling obscures detail by getting lost in endless resonance, isolation reveals detail by reducing ringing.
What you are hearing is with only a very limited and skewed form of isolation. Springs are much better. You can buy ordinary ones on Amazon for peanuts. But springs need to be tuned to the mass of the component to work well. This is a pita to find. So a better budget solution is Nobsound springs as then you adjust for load by changing the number of springs.
This still leaves us with the problem of resonance. We have eliminated a lot but there’s still some because the springs aren’t damped. But too much damping and the spring reverts to something closer to sorbothane, which we don’t want.
The optimal damping factor, at least according to Townshend, is only about 1%. This seemingly minuscule damping factor seems to be the main thing that accounts for the profound improvement of Pods and Podiums over Nobsound.
That’s the theory. I never trust theory that much. So I tried all this stuff. All sorts of cones and spikes. Sorbothane. Ordinary springs, Nobsound, and finally Townshend. It’s not even close.
But just in case you trust neither my theory nor my ears (which I always say do NOT! DYODD) then you can always check out the yt video where Max Townshend shows a seismic iPad that demonstrates visually and clearly exactly what I am talking about.
This is sufficient "theory" to satisfy my curious mind. That is, it's a clear and reasonable explanation of how and why decoupling may work the acoustic wonders it does work, as far as my ears tell me.
In fact, it's because of your advocacy for Townshend podiums a year ago or so that I was led to try decoupling, albeit cheaply with Sorbothane. But I'm willing to believe I could improve things even more by at least going to Nobsound springs. Someday, perhaps.
Again, welcome back. We've missed your wit and wisdom on this forum.
In my engineering degree we studied the effects of vibration and movement on adjacent objects and machines, it is clear that one moving and / or vibrating object creates energy that has effects on adjacent objects and machines. This is particularly the case if objects are close, creating the same energy and coupled. As hifi electronics and speakers are extremely sensitive machines there is certainly resonant effect in both directions. The most obvious way is to de couple the objects, this is most often performed by separation (distance), interference (place something between them), or isolation ( de couple one or better still both, from the energy pathway). In a small room and with the need to have speakers relative close together to get proper imaging then de coupling is likely to be the preferred solution.
Funny I watched a video where the guy measured the speaker resonances using three different isolation methods on YouTube. I’ll see if I can find it and post it here.
Here’s Credo Audio Switzerland demo of coupling vs de coupling:
I purchased a bunch of Townshend pods and bars for under my gear and former speakers. I liked how they made my system sound and found their service to be top notch. In the end I sold them because I found them hard to place and work with.
If your gear is much heavier on one side, then these can be cumbersome to work with and dial in. I had one heck of a time getting the proper combination under my Circle Labs integrated amp and Mojo Audio dac. Ended up with five pods of various ratings to finally “work” under my amp. It was still not quite perfect and one spring was not ideally loaded.
I ended up replacing these Townshend products with Live Vibe Audio Points under my electronics. They were far easier to work with, under electronics, and actually improved the sound in some ways. Articulation from top to bottom was improved and well as overall resolution, speed and imaging.
I am now looking for some footers for under my Fyne F704 speakers. They are much heavier in the front and am considering both Audio Points and Townshend.
Not excited about 150 pound speakers on the sharped tipped Audio Points resting on the matched coupling discs on my hardwood floors. However, based on my past experience with the Townshend Pods and bars, these speakers are sure to be a frustrating set-up experience. I don’t think the Townshend platforms will fit/work under my speaker.
Both Audio Points and Townshend offer great sounding products. Townshend Sounds a tad more warm and full while the Live Vibe products sound more articulate and resolved. At least this has been my experience. The set up frustrations and challenges were real for me and another factor to consider with these types of products.
Audio Points couple while Townshend decouples as I understand the products. Both products have sonic advantages.
Forgot to mention how the weight and length of your power cord and cabling can also add to the frustration of proper Townshend Pod placement and functioning. My integrated amp has a long and heavy power cord on it that hangs off the back as my amp rests at the very top of my 4 foot tall audio rack. This makes the dialing in process additionally challenging with the Pods
ALL components on Sorbothane. IMO, and especially for bottle rockets, all components should be isolated. In an earlier life in previous concrete slab home, components were in one room and speakers on spikes in another. Many good studios have the mains rigidly mounted while other have them compliantly mounted. Gear maybe in a separate room or in a control room alcove trading cable length for vibration control. There's no free lunch.
Current media room floor is 2nd over garage:
Spica TC-50 on shot filled spiked stands and 4 Sorbothane pucks to stands.
LFT8b on sand filled Sound Anchor stands on spikes with damped spike protectors.
Like almost everything HiFi, it's local. Change the program and the perceived improvement may vanish.
I believe you have a SA stand as I do also. As an inexpensive solution, I use velcro looped around heavy power cords and then around the rack above to help relieve the weight hanging off of the component. It is not something that can be seen easily, the velcro is easy to adjust as needed, and in my system it serves the purpose.
In the beginning and for quite some time all my efforts were with speaker cables. Power cords and interconnects were routed away from each other, but with no attempt at isolation.
Until one day I had all these extra speaker cable elevators laying around and thought, what about power cords? Much to my surprise the improvement was almost as great as under speaker cables.
One day looking at my turntable, the phono leads going down to the gain stage touch the rack at both ends. Surely whatever vibration is in the rack winds up transmitting along the lead into the arm and this can't be good. So I rigged up a way to suspend the phono leads at both ends. Very nice improvement!
My friend in Belgium with a killer Magico Q7 system tried this, was floored at the improvement.
Gradually over time my whole system has been isolated and floats like this. Power cords, even the ones going to subs, benefit about as much as anything. This I find odd, because suspending the 3 power cords going to my subs seems to make an even bigger difference than the power cords themselves! The only thing I can think of is, without isolation they wind up feeding vibrations into the conditioner and everything else, just like the phono leads into the arm.
Isolation is so important, it even predominates with the power cord going into the motor pod of my Sovereign turntable. I've upgraded turntable motor power cords before, always with a nice result. But was disappointed with the Sovereign. Odd, since the power cord being used was a lot better than anything I had done this with before. I could only surmise maybe because it is so stiff?
So after a few failed experiments I thought well if isolation is so important maybe instead of all this crazy good expensive wire that is thick and stiff how about try cheap hook up wire that is soft and flexible? Just for the last few inches into the motor.
I soldered this to a spare IEC and connected a Synergistic power cord. Success! Isolation uber alles!
Hi Mitch2, I had done that for some time with the Townshend Pods. I had no other choice with my rack. It helped me set up the pods a tad more easily, but after selling the Pods I just let it hang free of floor, other cables, rack etc…
I am now looking for some footers for under my Fyne F704 speakers. They are much heavier in the front and am considering both Audio Points and Townshend.
Not excited about 150 pound speakers on the sharped tipped Audio Points resting on the matched coupling discs on my hardwood floors. However, based on my past experience with the Townshend Pods and bars, these speakers are sure to be a frustrating set-up experience. I don’t think the Townshend platforms will fit/work under my speaker
I agree with your assessment. The Live Vibe audio points are well thought out, utterly effective and excellent in actual use. For your big speakers have you considered using the larger (More stable) footprint APCD5 discs? 4 of these per speaker would seem to provide a stable and secure base.
I read a review a few days back on a speaker and the background story dealt with coupling/decoupling. The maker said not to use springs as the speaker cones are meant to work against the cabinet holding them and if the speaker can react and move with input from the driver, it would lessen the speakers intended performance.
The graphs show the vibration in the stands. They don't show the delta between the driver motion and the cabinet. If the driver motion is different, then the graphs are a red herring.
That seems perfectly rational to me. No doubt that the preferable method of managing vibration/resonance is dependent on the particular speakers and circumstances. I don’t believe that universally one approach is superior to the other without any exceptions.
"How about for monitors on stands? Between the stand & floor or between stand & speaker?"
Follow and apply the logic of isolation. Anything touching anything else sets the whole thing ringing. Isolation works by minimizing the amount of stuff ringing. Springs under the stand leaves the speaker/stand to ring. Springs under the speaker isolates from the stand minimizing the amount of stuff subject to ringing. So that’s the way to go.
sorbathane feet are okay but they still don't stop the vibration from coming back into the speaker and smearing the sound, the best speaker isolation product out there is the Townshend podiums, they isolate down to three Hertz and also stop the Earth vibration which is constant from shaking your speakers as well, they're not cheap but best upgrade I've ever done to my system, sounded like I changed the electronics to more expensive gear, well worth it, will never take them out from under my speakers ever, I've got the monitor audio platinum 200 ll.
Over the years, I have tried multiple types of spikes (including Audiopoints) into the concrete floor beneath my 175 lb main speakers (inc. stands), and also under my two 160 lb subs (inc. stands). About a year or two ago, I removed the spikes and tried using damped springs beneath the speakers and subs, and I found the springs to be an improvement. Most recently, I have switched to using Herbie's Giant Fat Gliders both for convenience and stability, and I have not perceived any sonic detriment compared to using the springs.
After looking at this thread, I put the springs back under my speakers just for fun and found that I actually like the sound of the Herbie's Giant Fat Gliders better, I know...blasphemy, right? What would Max Townshend say? Springs, sorbothane, silicone, or Herbie's dBNeutralizer all provide some type of elastic damping and isolation. To me, the Herbie's products resulted in slightly fuller sounding body and better bass/dynamics, while the spring supported speakers sounded slightly thinner. The difference was noticeable but not substantial, and not as apparent as changing from spikes to springs. Maybe the differences I heard were the result of vibrational feedback or some slight distortion, but to me it doesn't really matter because it sounded better. FWIW, both the springs and the Herbie's products sat directly on commercial grade carpet over a dense commercial grade foam pad, over a concrete slab on grade. With either solution, over time the carpet and mat became quite compressed at the contact points. YMMV
Vibration isolation in audio is a subject surrounded in mystery half truths and any number of wild theories. As an engineering exercise, the explanation is quite straight foreword and may be explained by the “Theory of more stuff”.
Take a surface, be it the floor or a table, on which your hi fi component is placed and it is desired to reduce the vibration from the support to the equipment. The way this is done is to put “some stuff” between the equipment and the supporting surface. There are three possible outcomes.
1 The vibration in the equipment is more than the vibration in the support.
This is not possible as if it were; the energy crisis would be solved! More
out than what is put in. Free power forever! Unfortunately, this scenario
contradicts the first and second laws of thermodynamics, so is not
possible.
2 The vibration in the supported equipment will be the same as in the case of no stuff. The chances of this are one in a million because something has been changed… it may be the same, but that is extremely unlikely, therefore, the only possibility is,
3 The vibration will be attenuated, to a greater or lesser degree, and this is the case.
There are many products out there that do in fact attenuate vibration. Be it spikes on glass, wood and slate, aluminium spikes in cups, ball bearings in cups, solid plates separated by compliant sheets, lead, Bluetack, sand, marble, concrete, the list is endless. It is also known that multiple combinations of the above produce better results because there is more stuff. E.g. multiple platforms stacked really high.
The engineering approach is to get the best result in the simplest manner by optimizing the “stuff” and way back about two centuries ago the Victorian engineers came up with the solution…. the spring! The spring may be anything “springy”, from elastic, rubber, coiled steel, straight steel, air-bladders to flexible wooden strips. As long as it has sufficient spring or compliance, when optimised with an appropriate mass, a mechanical low pass filter is realised.
The ideal is to have the resonant frequency as low as is possible, ideally around 2Hz in both the horizontal and vertical planes and with a damping ratio of about 0.16. This will give an attenuation of about 25dB at 10 Hz increasing at 20dB per decade above. This will ensure excellent isolation for the deleterious audio system vibrations which are from 5Hz to 500Hz.
Couple then decouple. Couple you speakers to a large mass, mine are 450 x 330 x 180 mm laminated pine blocks ( large butcher boards), these are then decoupled from the floor with audio springs (Nobsound type). This essentially isolates any vibration to the speaker / mass alone, lowers any vibration to below anything audible and does not transfer to or through the floor. You can measure this by placing a measuring instrument (programs for your iPad are OK) on each speaker with only one playing at a time. You can see the difference clearly. The sonic effect is quite marked especially separation and sound stage.
The argument that convinced me to isolate speakers says that coupled speakers waste energy by delivering part of their energy into the floor or speaker stands.
Every speaker I have sounds better isolated.
And some speakers never sounded quite right until they were isolated.
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