Turntable Isolation Journey
Nearing the end of my journey to solve footfall & feedback issues in my small-room "home office" system with very bouncy floor and flexible walls. Turntable is the only source here -- and it’s a Clearaudio Innovation Compact with no suspension or special isolation feet. This system always sounded good, but was rendered nearly unusable at higher volumes due to turntable isolation that was inadequate relative to this room’s challenges. The worst artifact was when structure-borne feedback from the speakers would cause amp clipping on bass-heavy tracks. This clipping would manifest as an extremely loud singular POP sound, especially hitting the tweeters. It only occurred during the loudest parts of track with bass-heavy elements, and was so loud it was still significantly above the level of the music -- much louder than a POP you would hear from vinyl surface defects. The POP sound was startling, and clearly very bad for tweeters (fortunately my Tannoys seem to have survived several of these incidents). For a time I thought these POPs were from static electricity discharge, but they were NOT. In my quest I tried many solutions and tweaks over a few months, and I’d like to share a rundown of what worked versus what didn’t.
What Helped (MVP products & tweaks):
What Underperformed:
What Was Worthless (Don’t waste your money like I did):
I’m not going to bother expanding upon these; suffice to say they had no discernible positive effect.
I'd love to try a Minus-K some day. Amazing tech; they truly look like magic! Though, I do feel this particular system is "well enough" solved for now. Perhaps my opinion will change in the long run. Haven't tried an active platform either, but I've read enough -- like the problem with footfalls -- to give me pause on them. |
The Minus-K solution looks amazing and was absolutely next on my radar, but the Townshend platform in conjunction with other noted factors has solved this particular system to my satisfaction :) That's interesting on the Vibrasystems rubber, I'll look them up - definitely cool how effective some cheap solutions can be. And conversely frustrating how INeffective some expensive solutions are; of course every setup is different! |
Nice, the Herron is a very good phono stage and I still have one around. At one point I thought the different subsonic filtering between phono stages and SUTs could have some impact, but in the end didn’t find any meaningful difference among the combinations tried (4 different phono stages, including Herron with and without SUT). None of the phono stages were even slightly at fault here. Your post reminded me, I also tried the KAB rumble filter. This was 100% effective at protecting from amp clipping and always kept the woofers rock solid steady -- no more flapping! However I felt it DID have a slightly negative impact on ultimate transparency and dynamics. If left with no other option it’s a good tool, but addressing the issue via proper isolation is superior. I feel my currently isolation grants (roughly) 90% the protection of the KAB, without sonic penalty. Very nice! Thanks for sharing your considerable experience. I feel like a baby in this area, but am happy to at least be crawl-walking now lol. Concrete slab floor is a dream for a future system :) You Ovation looks fantastic with that Tracer arm, on that Townshend! The Ovation and Innovation Compact are truly the "sweet spot" of the Clearaudio lineup. You can hear the same quality of sound that’s in the Master Innovation. I almost bought a Delos and am glad I didn’t, but it’s at least possible these products could be effective in some systems. I was also kind of shocked how much energy still gets dumped into my suspended wood floor through the Gaia III’s. Superficially these feet are "suspension like", but unfortunately they don't seem to be as effective as a real spring suspension. I bet the difference with a Townshend podium would be huge. |
@gakerty I wouldn’t worry a bit about that 7hz resonant frequency. As you know, these Clearaudio tables don’t rumble...at all. And you can get the ring clamp if warps ever cause woofer flapping problems. For a time I though I could (at least partially) address my issues by choosing an arm+cart with the "right" resonant frequency, but the truth is there’s no avoiding the need for proper isolation -- until you solve this, almost ANY resonant frequency will be excited by footfalls and/or LF feedback. |
Thanks @gakerty Yes, I still have those Rogue Apollo monoblocks -- ran them as my main amp (in non-Dark and later Dark form) in the big loft system for the better part of 10 years. I tried swapping lots of components during the struggles with this smaller system. I must say, the Apollos are so powerful they were NEVER once driven into clipping, even at loud volumes with improper speaker & turntable isolation. However, I realized throwing gobs of power at the problem was not a proper solution. And in the end, I prefer the sweet refined sound of VAC tube amps, albeit at a much higher price tag per Watt. The Apollos are still great amps! I've been really pleased with the Tannoy Glenair 10's in this small system. I have Canterbury GR in my main system, which I love, and have been surprised how well the much cheaper Glenairs hold up (unfortunately long discontinued). They're easily my 2nd favorite 10" Tannoy after Kensington. |
Thanks for the great feedback everyone :) @macg19 Awesome -- you’ll love the Innovation Compact! I currently have this 12" Universal on it transplanted (left over) from my Master Innovation, but a Tracer or Graham Phantom should be an ideal match. I’ve actually been meaning to get my 10" Phantom over here -- I’ve preferred it to the Universal in prior comparisons, and was wondering if the 12" length might exacerbate isolation issues? And you’re right, this is not a proper use case the Symposium. I originally got it for my girlfriend’s Fluance RT85, and just had it laying around. But it didn’t help the Fluance, either :( @no_regrets Thanks! However, it was the very helpful @pindac who has the recommended Vibrasystems product. @deancacioppo A wall mount is an interesting option, but a) this system resides in my girlfriend’s home, and b) I was too lazy :) @prof Awesome! That’s always refreshing to get validation from someone with a similar journey -- thank you. Hockey pucks under speaker spikes is a brilliant idea, I’ll try that. Also agree you’re onto something with finding the right balance between speaker isolation and room interaction. These various solutions clearly impact perceived bass response. Now that my isolation has been properly solved at the turntable, I’m free to get more experimental with speaker mountings -- I can pick what subjectively sounds best rather than having to choose feet for maximum energy reduction. Also, I really tried to figure out how to get the rack into another room, but it just isn’t workable in this particular situation. @singingg Interesting note on the double hockey pucks! I was wondering why pucks might work so much better than (say) Herbie’s gliders, and part of me thinks it might have to do with the nice mass & size of pucks. No material, no matter how magic, can work effectively if there’s not enough of it. Even the "giant" Herbie’s gliders are simply puny compared to a single hockey puck. Pucks are massive enough to have effect, but still easy to work with under components. So that theory works nicely with your double hockey puck assertion. I just ordered 2 dozen more from amazon :) And yes guys, concrete under your floor is the best lol. I feel like we can categorize rooms by their challenge level for vinyl sources:
Also forgot to mention, I’ve had these 1" thick granite slabs since forever. They ring like crazy. Tried them under my speakers (with Herbie’s Giant Fat Dots under each corner) and they just sounded BAD. Really bad. I realize this was not a good setup -- granite with proper damping (e.g. sandwich with sheets of some kind of isolation material) could possibly be great. But my lazy granite application was just awful. It made the sound bright, dry, brittle. |
It’s very simply just a shim of flat material that you wedge tightly between the rack and the wall behind it. Just push the rack against the panel to hold it tightly in place - press & friction fit. For the shim I’d previously used a semi-rigid panel (the red backing in my 1st turntable pic above), but now I’ve ended up using a single 2" thick Auralex foam tile. I like the foam because its compliance facilitates good contact area for both the wall and rack frame, plus it helps reject vibrational energy in the wall itself. The idea is that nearby footfalls (on bouncy floors) cause a ripple shockwave which sends your rack into oscillation, because it lacks infinite rigidity & mass. The maximum displacement from oscillation is observed at the TOP of the rack (normally back & forth, but could also be side to side), which is unfortunately right where our turntables reside. Such displacement can easily excite the arm + cartridge resonant frequency (even if in the "ideal" 8 - 12 Hz zone), which causes us so much angst. The idea with the wedged material is to damp & reduce this oscillation, by bracing the rack against the wall exactly where it’s needed. This significantly reduces both duration of oscillation and its maximum displacement. It works kind of like a constrained layer sandwich that "changes direction": floor > rack feet > rack frame > shim > wall. It allows your rack to leverage the strengths of both floor and wall. Before this "hack", what I noticed was a sort of tradeoff with my Sotto Voce rack frame which was rigid but low mass: the rigidity somewhat reduced maximum displacement, but then this rigidity happily transferred more of the shockwave energy to the turntable. Meanwhile the Lovan lacked rigidity which resulted in a HUGE max displacement, but the frame itself was kind of lossy on overall energy transfer. The result was that both racks were roughly equally bad with footfalls, but the more visible displacement from the Lovan was quite disconcerting to see. The wedge / shim trick works well with both racks :)
I was looking at SolidSteel racks a while ago and almost went that direction. Quite honestly they look like a solid back-for-buck on a nicely rigid rack. I think if you can get enough contact area on the frame to brace them against a wall, the result should be quite excellent. And yes, HRS racks look amazing too but like CMS they are quite expensive and I’m still not sure they’re a complete solution on their own to combat these really bouncy floors. |
Oops, sorry it was indeed @drbond with the Vibrasystems recommendation - my bad! Could you please provide a link to us? :) |
@pindac right on! :) |
@sokogear Yep, a suspension alone (whether SOTA, Townshend or other) is not enough to guarantee immunity to footfalls. A large enough displacement will still excite the suspension, which in turn can excite the arm + cartridge resonance, which will certainly flap the woofers and other nasty stuff. My room here is also a suspended wood floor over a crawl space. We appear to have very similar use cases :) It was a combination of rack bracing, hockey puck feet, and Townshend platform that got my setup "effectively" impervious to footfalls. The newly braced rack reduces maximum displacement enough that the Townshend successfully mops up the remainder. They really have to work in tandem (a wall shelf would be very similar in function to my rack bracing). And the acoustic feedback is also now also solved well enough -- yep they’re inter-related to some degree.
@mijostyn This is the older series Nova V (originally a Star III), not VI. No eclipse, no magnetic thrust. I was pretty bummed because VI was announced not long after I got the V rebuild done. And the VI upgrades indeed appear to be quite substantial. So now I have this V that’s still really nice but kind of a bummer when I think about it. Sure, I didn’t give the Nova V a fair shake in this room, and I’m starting to suspect its suspension needs adjustment. If the tension & leveling on the 4 springs isn’t EXACTLY right you get all this jumpy side-to-side movement on excitation, which is really bad. Though I’m sure it would work well enough now with the braced rack. However I’ve already gone through a number of cartridges / arms / phono stages in this room and feel I’ve got a good handle on what each part contributes sonically -- previously went through the motions with these same parts in the main loft rig, too. The SOTA sounds really good but I’m simply preferring the Innovation Compact these days.
@ghdprentice My friend has his HR-X on an SRA and it worked wonders for him. But he’s got an extremely rigid massive rack on concrete slab. Totally different use case to this room. I can pretty much guarantee any HRS / SRA / CMS platforms will not "move the ball forward" for the significant issues posed in this room. They have to help absorb a relatively large displacement. And that requires movement (a suspension). Unfortunately I don’t see those 3-layer vibrasystems rubber feet doing the trick here, either. |
Since the structure-borne energy has been addressed, airborne energy doesn't seem have been be a big problem. The rack with turntable is located several feet down the left side wall. And I don't want a digital source lol. |
@jollytinker Yep -- I hopped on amazon this week, and now I’ve got pucks under the tube amps and speakers (spiked) too. Sounds GREAT! Agreed, it’s funny how much of the recent audiophile vibration philosophy abhors the idea of rubber because it will supposedly "store energy and release it later, blurring the music". We’re told it’s better to dispose of the energy by heat conversion. Well, sure! But what % of the energy can really be converted in this way? Especially without a LOT of lossy material acting over a very large area - certainly much more than the amount of "magic" material in these audiophile feet. Some of these companies will patent their own blend of polymer (which must be very easy to spec & outsource now) and sandwich layers. Is this really better than a fat rubber puck constrained between hard surfaces (e.g. spikes and floor)? And how stable are these polymers going to be over time? The pucks last forever and can be replaced at a buck and change per pop. Maybe the pucks work so well in some scenarios (like ours) because they’re more effective at managing the energy -- including reflecting it back away from the component -- even if they don’t convert as much of it to heat. Or maybe they just work better because there’s more mass of stuff there than in the stingy audiophile feet (at 10x - 50x the cost or more). There’s much more of the "active" material in a puck than in a Herbie’s glider, or a Gaia III, or Orea (a lot of which appears to just be an impressive looking metal shell). |
To be clear, the wall in question here is an outside wall. There is indeed a lot of vibration energy going through the walls too, but the Auralex foam tile I’m using to couple the rack to the wall helps reject a lot of this. It’s a give-and-take between how tightly coupled the rack is for support, and how much vibration transfers from the wall. I still use a CMS Black Platinum filter for the top self which is NOT in contact with the bracing material, and I’m certain it’s doing a great job filtering out the additional wall energy. The main net result from wall contact here is it effectively damps and attenuates footfall shockwaves. I’ll say again the Minus-K looks amazing. If I got one, I would still keep this rack bracing arrangement. Any isolation platform, whether passive or active, is going to work better on as a solid support as possible. The solution I have now, culminating in the Townshend platform, finally meets my needs for this system. I’m not advertising this as a one-size-fits all solution or a "reference" system of any kind. It’s simply scaled down version of my main loft rig (with a lot of hand-me-down components), for enjoyment in my girlfriend’s (challenging) suburban home. I could NOT get problem free vinyl sound in this home (even tried different rooms) until I hit on this combination of isolation elements. Previous attempts experienced the whole gamut of ills, from massive acoustic feedback to the usual footfall skips. No warranty, implied or otherwise lol. LOVE the stories on hockey puck benefits :) Keep telling me about your rack bracing solutions too. |
Yes, let’s keep it veered towards friendly and non-political -- or at least less political since it's hard to avoid these days. Sure we’re mostly Americans and Canadians here; we generally like each other but also love to rip on each other :) @whart my gosh, that is a beautiful setup and isolation solution you’ve built! Clearly a labor of love. |
Hi Robert, Every room & system is different so it will be a "wait and see" scenario. You have some factors in your favor:
Then we have the unknowns:
The Symposium was of no help in my case, but that doesn’t mean it won’t be effective in your setup. Give it a try if necessary. The Townshend platform & rack bracing was ample solution in my case (the Townshend alone may be enough), so I think that should be explored as a cheaper alternative to the Minus K. But you’ve certainly got enough table to more than justify that too! Those Air Force tables are gorgeous btw! The III Premium is what I’d go for in the line, too. I’m jealous :) |
Yes special shout-out to @mmcnult1 (Matt McNulty / The RockDoc) -- I’ve been friends with him on Facebook for a while now, and he’s been an all-around helpful and friendly guy in several of the audiophile groups there. I knew he does a lot of work with Townshend products (specifically the tables) so when I realized a Seismic Platform might be the right idea, I approached him to help coordinate the purchase. Smooth sailing as expected -- absolutely 100% recommended; if you’re curious go talk to him :) Of course Matt endorsed Townshend isolation as the total solution to my issues, and he was spot-on. He actually recommended a single podium over the platform, and I would’ve LOVED that solution, but simply couldn’t make its outrigger footprint work without a totally new rack. I’m still looking at the huge Master Innovation in my big rig and trying to figure out how to make a Podium work there. I don’t have the footfall or feedback issues there (ever since I got the Maxxum rack), but it can’t hurt to further clean up any stray energy, right? Plus I think the podiums look wicked cool :) Hmm, maybe on my beastly VAC amps...
@brunomarcs I have B cells and this table weighs probably 30 - 35 pounds with all clamping. They have to be somewhat springy for good effect on a given load -- I found they compressed about as much as I expected; just a bit as you can see in pic. The fine leveling settled over a few days under load. There’s a fellow on a Facebook turntable group, and his pods show a LOT more compression -- quite honestly, no I would not like that. I’d try the next level up of load cells in that case.
@bdp24 Yep, the Pods and Bars are intriguing options. I just love the look of the Podiums but those outriggers eat up a lot of real estate (though I understand their function) and space is unfortunately at a premium in both my rigs... |
Just an additional follow up -- I’m really enjoying this setup now. It sounds absolutely wonderful - engaging, organic, full-bodied, liquid. Good depth to the image. Very smooth. VERY low listening fatigue. All the things I like. Absolutely fantastic Tannoy Prestige sound from these Glenair 10s. Soundstage and low bass performance are a bit constrained by this small room, as to be expected. Nothing that jostles me out of the music, though. I’ve played really quite loud now with absolutely NO sign of strain from the amps. Footfalls are incredibly well damped -- even at these volume levels (with needle resting still in the groove) there is hardly any audible & visible feedback through the speakers now. I normally relegate digital sources to my headphone setups (of which I have quite nice ones, especially the Stax based ones), but as a "sanity check" I occasionally pull some digital source out to a Tannoy rig. I did this last night -- the digital rig on hand was nothing special, but serviceable: Questyle CAS192D DAC, Audiophilleo 1 w/ PurePower USB converter, Sony NW-WM1A DAP with 1TB of lossless FLACs and high res USB output dock (streaming via Node 2i sounds significantly worse than this DAP). It sounds OK but even in this room, with all its energy problems, the vinyl setup absolutely CURB STOMPS this digital rig for enjoyment factor. Not even close. This happens almost every time I try to compare digital to vinyl. No, it’s not at all a fair $ to $ source comparison but I don’t really care as the majority of my music collection is on vinyl :) |
@pryso The sandwich type pads are an interesting alternative to hockey pucks. I'm all for these effective & affordable products. They're probably at least as effective as most audiophile footers ($$$), if not MORE so in many cases. Of course if you have severe energy issues (like in my room here) they'll hit their limits and then it's time to explore more significant (and costly) options like the Townshend. But for moderate energy issues, I think these cheap products are fantastic. Sounds like you have a very structurally sound room and you've smartly used a wall mount to boot. I bet that is a great setup! Enjoy :) |
Ah, my bad - my brain filled in "wall mount" when it saw "Target" because they're known for that. Anyways, sounds like you have a structurally sound floor, which is worth its weight in gold for these applications. Definitely, amp & speakers are worthy of experimentation too! :) |
@boothroyd Yes, a good observation -- I used to be optimistic the CMB itself could help provide isolation. However, my observations across the range (Innovation Compact, Wood, Master) are that it does not provide effective isolation. I think the issue is that there’s only compliance in exactly direction: straight up & down. It’s still a rigid bearing in every other sense. Even where there is compliance, it doesn’t exactly operate like a mass-on-spring. The CMB’s function is to reduce bearing rumble and eliminate the ball & thrust plate wear, which it does brilliantly: these are exceptionally quiet tables, and they easily take on massive platters with 5+ pounds of clamping. If it were compliant in directions other than straight up & down, it would be a poor turntable bearing because this would elicit a wobbly instability (ala the MagLev turntable’s platter). |
I’ll defer to @tonywinga for better explanation since he knows far more about this topic. But yes, I was aware one should never stack springs -- since their resonant frequencies can interact in very detrimental ways (huge displacement amplitudes when excited) -- I believe this has to do with the constructive & destructive interference nature of waves. My old dealer actually warned me of this when I first got into vinyl. So you should never, for example, put a SOTA turntable atop Townshend springs. I don’t believe stacking "squishy" damping interfaces like Orea feet suffers the same problem. Or at least, not severely enough to be of concern in typical use cases. I also don’t believe combining springs with damping devices is a problem -- in fact that’s a great approach! The main issue would be loss of stability when over-stacking -- don’t risk that expensive turntable toppling over! Technically, my turntable's full vertical support stack is: @tonywinga I would like to better understand the actual differences between damping devices and mass-on-spring systems. Doesn’t a spring system act "kind of" like damping above its resonant frequency? Or is there something else going on? And don’t damping interfaces also have resonant frequency? Thanks!! |
The 1.5" thick brown wood layer in these Clearaudio Innovation and Ovation tables is panzerholz :) I’ve been admiring the Taiko audio panzerholz platforms. And I’ve definitely wondered if a nice slab of panzerholz atop the Townshend platform might be a good idea. @tonywinga Yes, I was aware the tonearm mass + cartridge compliance forms its own spring system, which can be difficult to deal with. Even when you’re right in the "ideal" 8 - 12Hz range, what they don’t tell you is that footfalls (etc) can very easily excite this resonance until you’ve properly addressed structural issues and isolation in a setup. I could observe this excitation very plainly -- by both sight and sound. Finally now with rack bracing, the Townshend, and (to a lesser degree) hockey pucks, this excitation no longer occurs :) Probably the worst case of feedback I’ve ever observed, even worse than this small room setup (before current solution), was with one of those Clearaudio full-magnetic bearing tonearms ("Concept", "Clarify", and "Verify") on a Clearaudio table, on a suspended wood floor, near the speakers. The magnetic arms act like their own spring system, and good god their interaction with other non-ideal system factors is just pure nightmare fuel! The hybrid-bearing "Magnify" arm (rigid in one direction, magnetic in the other) was a LOT better in this regard, at least. It looks like Clearaudio has either discontinued or de-emphasized these models in their line -- no surprise to me!! |
@dwette its footprint is an equilateral triangle where the sides are just under 15" each (including the steel pad spike cups). So the "height" of the triangle would be just under 13". So, 16" x 16" should work. It is indeed a 12" Universal. I had it leftover from my Master Innovation, since I prefer FR64fx, FR64S, and/or Graham Phantom Supreme there. It looks cool on the Innovation Compact, but I’m not sure if there is a real performance advantage over the 9" version. |
@dwette My platform is the standard Size 3 (the largest):
It's a little tight in the 16" dimension, but works. I inquired about a custom sizing but since it would be extra cost and wait time I just went for the standard 3. The way I have it configured in pic does a reasonable job centering the mass, so that only a little bit of leveling adjustment was necessary. |
@dwette Lovely! My experience is that this Universal 12" arm seems to do best on cartridges with a dynamic, vivid sound with good treble energy (or even a bit extra). My Koetsus are a no-go on it, but it does excellent with Ortofon A90, Shelter Harmony, and even Benz Wood SM. The Lyra might just be an amazing match! I’ve come to appreciate the Innovation tables more with time, and of course as I provide better structural isolation. Started with an Innovation Wood 10 years ago, and am sorry I sold it. They all have an exceptionally quiet noise floor and very clean sound to go with the great looks. |
