2. analog
  3. 184344-3032

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 :)

128x128mulveling
recklesskelly
330 posts
 

Engineered concrete slabs are the best. Last 35 years all my homes have been built on them. God bless the unstable soil in the SW United States and Florida. 

whart's avatar
whart
3,037 posts
 

The Kuzma, like the Herzan, are active units and based on my discussions with Franc Kuzma and Mike Lavigne, respectively, neither product is designed to deal with footfalls, which the Minus K is capable of absorbing. Instead, those active units maintain a sort of constant balance through a feedback loop (my description may be crude but I understand similar tech is used to keep centrifuge floors level).

I’m running 245 lbs worth of TT, including HRS plinth it sits on- the Minus K has a metal top so you want something between that and the table/plinth unless the latter is already able to deal w/ a metal interface.

I use the largest bench top model- they are spec’d to load and you want to load them close to max to get the most out of them. Since I’m in an old Victorian wooden house with wood floors, the Minus K wasn’t an extravagance but a necessity. If you pursue the active isolation tables, make sure you have a stable base already because given my understanding above, they aren’t meant to deal with wallowing floors and the sort of resonance created by footfalls. I’d say the engineered slab is the start.

mulveling's avatar
mulveling OP
1,895 posts
 

@whart 

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.

knittersspouse's avatar
knittersspouse
26 posts
 

I have my old Dual CS-7000 sitting on my file cabinet.  Some would expect it to ring like a bell, but they don't understand that in addition to providing storage for media and cables, it is also a 700# fire safe on steel wheels which have only a very narrow line contact point with the floor. it even has spoke wheels for better isolation!  For $50 at a surplus office furniture store it has a cost/benefit ratio that cannot be beat.  At about 5 feet high, it puts the platter above the line of fire from the main speakers and just about the perfect height for me to check stylus condition and positioning.  

For name-droppers, the cabinet is a 4-drawer Remington Rand "Safe-File", made in the USA some time in the 1940's. Many thousands were made, but you will do better looking in an office surplus store than an audiophile shop.  I frequent both but only locally as shipping can be a bear in both categories.  

                   "Precisely calibrated feedback can be of great value..."

 

pindac's avatar
pindac
2,864 posts
 

I n my present listening environment, I have a Robust Design for a Cantilever Wall Mount Shelf that is set up to be used.

This can take substantial weight. I have used it with a Tiered Sub Plinth Set Up built of it and also have had a Sub Plinth Suspended from it.

Either of these methods have presented quite similar, their are small differences, as is always the case when a variant of a Support Structure is produced.

Due to Source Equipment Security concerns the Cantilever has not had the weight loaded in a manner I usually put in place on top of a Rack Structure. 

The Cantilever Shelve is used for the Digital Source and the Rack is used for the Analogue Source.

When creating the Structure under the Rack, producing methods for the Bracing of the Rack (dense foam as separator and tension strap the Racks together), along with the methods used to produce the TT Supporting Structure above the Racks Top Shelve. The assembly has proved to be very good for creating interesting discoveries and continued reconfigurations of the Structure has really honed the presentation to one I do not want to be without. 

The Racks come with a cost, but it is bespoke produced for me by a now deceased friend who's hobby was wood turning. Footers are going to cost varying sums of money, there is a need to Spend that is difficult to avoid or Clone, this will be needed if the better experiences are to be had through using certain types of footer. The combined cost of all the materials and footers collected over quite a few years is probably less than a £1000, the recent acquirement of Densified Wood Board has been £500, but I do see more of this to be purchased as it has impressed so much. For me, I have paid to learn a variety of lessons, certainly not the type of monies a dedicated Isolation Platform will command. I have been hands on, enjoyed the curiosities and thought processes used, the monies have been well spent in my view. 

What is the outcome of working with the different interfaces that can be produced as a equipment support and for the management of energies thar are being transferred. For me the system that commenced being built approx' 20 years past and much of the early acquired devices that remains in use, is a keeper.

The system mounted on a well thought through structure has enabled me to have identified items used in the system that are in my assessments functioning as constraints.

The more recent choices made for the replacements of items recognised as constraints are pretty much showing to me, the system as built over many years is a superb experience and a is to be kept. 

Run parallel with this the non-EE Skilled interfaces that can be put in place and there is something very special to be achieved. I certainly don't consider needing new anything at a get on board fee of $5k, 10$ or up to $50K, I have demo'd A/B against items up to these values, and am not feeling there was something amiss from my end.

     

  

More to discover