Once you go concrete, you can't go back!
Concrete slab floor is a dream for a future system :)
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):
- 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.
- 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.
- 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).
- 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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- 137 posts total
@noromance +1 for concrete Although it's very difficult to implement across a bouncy wood floor. My system is in the basement standing on very large marble and stone slabs, they standing on the concrete screed in the ground. I have called this infinite mass loading. If we can take the mass of Earth to be infinite relative to that of the little stylus riding the little groove. Those suffering the pain of a suspended floor might consider putting two rolled steel joints in it spanning between two solid walls and build the system supports onto those. A radical solution but a solid one! When considering the cost, consider the cost of your system and media and the long-term compromised sound; not to mention the cost of all the isolation systems you want to try. |
I am blessed with a concrete floor in my house-addition dedicated listening room. I have steel post supports in my stand filled with sand. I removed the spikes and set them on a single hockey puck. I have glued and screwed two piece of masonite under each shelf for great density and vibration absorption. Audiophile riddle : What is better than a hockey puck? Answer : two hockey pucks Yes sir, I discovered this by complete accident. Per this discussion, I have three stacks of two under my Project RPM 10 isolation base, touching the base, not on the footers (experimentation recommended). A tweak of the tweak : hockey pucks are seldom flat, with one side a little concave and the other a little convex. Flip them until they seat. I use three stacks of two under all my full sized rack components, resting on the chassis, not the feet. This works sometimes even with small components like the iFi microphono 3 (1 set of two). For other small devices and my Furman power conditioners, I have found folded rugs suffice and can be cut to size. |
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. |
- 137 posts total