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):

  1. Townshend Seismic Isolation platform -- Single biggest difference maker, for combating both footfalls and structure-borne feedback from speakers. Amazingly-well designed and built. Leveling was a snap. Well worth the price! If you spend money on isolation, spend it here. Highly Recommended. I’m now considering more Townshend products for under my speakers and in the big loft rig.
  2. Rack Bracing -- Pushed rack right up against the wall (stud / drywall) with a 2’x2’x2" Auralex foam panel tightly wedged in between the top half of rack & wall. This SIGNIFICANTLY cleaned up rack oscillation from footfalls. I see a LOT of folks with nice turntables atop tower-style audio racks, and they could benefit greatly from this "hack". It is cheap & free; the only downside is you may need to reposition your rack. I learned about this "hack" by a couple comments buried in "turntable isolation" threads searched via google. This really CANNOT be overstated.
  3. HOCKEY PUCKS -- Placed under rack spikes in place of the stock aluminum cups or Herbie’s Giant Gliders. Just let the spikes sink right in! This actually cleaned up the very last bit of energy from footfalls; foot stomps with needle-in-groove are now DEAD QUIET. super cheap and effective! Far superior to most audiophile footer devices. Might also help in rack bracing by tightly constraining the rack between wall & floor (Herbie’s Gliders were too slippery).
  4. Rack positioning -- Get your turntable & rack away from the speakers. If you can move the rack far enough behind your speakers, that might be OK, but most rooms cannot accommodate enough depth for this. Placing the rack several feet down a sidewall worked best in this room. Choosing a structural wall also aids in rack bracing. Make sure you don’t place the rack in a room "node" where bass is amplified. Walk around while music is playing to find a nice quiet-ish spot. I kept my amps by the speakers and ran 5 meter XLR cables from the preamp / rack.

What Underperformed:

  • Critical Mass Sotto Voce rack -- the rack is gorgeous and nicely rigid, but doesn’t have nearly enough mass to combat the bouncy floor in this room. Once braced against a wall, the rigidity of this rack was allowed to shine. However, before the bracing, its performance was poor. I will say I have Critical Mass’s Maxxum rack in my (main) loft system on a more solid floor, and the immense mass & rigidity of that rack was game-changer for that system. I do like CMS products, but they are dearly expensive.
  • Critical Mass Black Platinum filter -- Top shelf of the rack. This actually has a significant positive effect, but is limited to the midrange and treble frequencies. It cannot combat footfalls or low frequency feedback. I still like and use this platform, but at more than twice the cost of a Townshend platform it belongs in this category.
  • SOTA Nova V Turntable -- I thought this table’s suspension would render it impervious to room issues, but it’s not. It helped with footfalls but some structure-borne feedback was still getting through. I suspect the suspension needs a tune-up. Quite frankly I think the OLD suspension (it started life as a 1990s Star III) was better tuned and more stable before it came back as a fully rebuilt Nova V, circa 2018. The new vacuum platter was a huge improvement but the new suspension has been disappointing. The Clearaudio deck also sounds a bit better, so now with the Townshend platform it’s an easy choice. Note that the Townshend also uses springs as its isolation mechanism, but I noticed that the Townshend’s oscillation is far better controlled and damped versus the SOTA. You can SEE and HEAR its performance advantage.
  • ISOAcoustics Gaia III speaker feet -- these seemed to have some small positive benefit, but honestly not a lot. Not worth the money.
  • Lovan Sovereign modular rack (three 10" modules high) -- these are very similar to the VTI racks I see everywhere (which I’m also familiar with). These racks lack rigidity and stability. I would not recommend placing a nice turntable on one of these racks. However, if you do, please brace it against a wall (Auralex foam works great). They’re relatively cheap and look good, so I at least understand their popularity. If you have this rack, at least try hockey pucks under its spikes :)

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.

  • ISOAcoustics Orea Indigo feet (under maple board & turntable).
  • Symposium Segue ISO turntable platform
  • Herbie’s Lab Giant Gliders (steel) - Placed under Sotto Voce rack spikes
  • Speaker spikes -- at least they look cool :)

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@mijostyn frames the challenge correctly. As for footfalls and other structural borne vibrations, there are only two solutions—siting your table on the basement level directly on the concrete foundation (or forming a concrete tower that rises to the main level—yes, some folks have done this!) OR going with a wall mount shelf, which MUST be fastened to a load bearing (usually exterior) wall. IME these are the only ways to address structural issues like bouncy floors and washing machines. The other suggestions offered here are not going to get you there—period. Once properly anchored and isolated, you can go after the airborne vibrations generated by playing music. Some of the solutions offered here make sense. After years of experimentation, I’ve got my Target PS-1 oversized shelf screwed directly into the studs on an exterior wall. I applied some foam weatherstripping to the mounting surface as an interface between the back of the shelf and the drywall and used the largest wood screws possible along with the largest washers possible to ensure that the shelf is securely fixed to the wall—I can hang on the end of the shelf and it doesn’t budge. Then I replaced the upward facing spikes with Herbies Giant Gliders and the MDF shelf with a 19”x21” Symposium Svelt Shelf (a drop in swap). My table sits directly on the Svelt Shelf and has its own integrated aircraft aluminum base with Isoacoustics footers (comes standard with the PF Harmony). While my rack and table are too close to my speakers—no better option in our current home—I can crank it up to unlimited volume and all I get is clean, clean music. FWIW my speakers are spiked to the suspended floor with Track Audio footers—highly recommended. You can see pics on my systems page.

It’s always a good idea to locate your floor-located turntable stand as close to an outside wall as possible. Or right above a support beam for the suspended floor. That’s where the floor is most stable, least bouncy.

Some new houses are built with the sheetrock walls mounted onto not wood 2 x 6's, but thin aluminum structures. Not suitable for a wall-mounted turntable shelf.

@thr1961 You stated "but hoping not to spend the extra dollars right now after the Safir..."

My comments and suggestions offered were to encourage the investigation and experiences that be learned from, as a result carrying out trials that have proved quite valuable in my listening environment. Nothing ventured, Nothing Gained, is the usual outcome of not being inquisitive and creating experiences.

There is a suggestion you bypass the ideas referred to, that are made by most of the contributors to the thread, negate all forum members reported on experiences and go straight for a $5K ancillary.

This is a typical Gon response from a select very small selection of members using the Analog Section. These few are always speedy at bringing to the forefront, that it is a multi $$$$$$'s fix. Very Very few are taking these individuals advice as far as I can work out.

 

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