Thanks for sharing your experience. I had quite a journey in trialing various isolation devices as well on my turntable,and found that they all imparted come sort of color to the music. The only isolation device that I've found to be completely neutral is the Minus K platform for the turntable. Besides spending thousands for a minus K platform, the next best option that I found (better than hockey pucks) was a three layered rubber isolation device made for industrial purposes to isolate various motorized components. The pieces I bought were manufactured by Vibrasystems. You can buy various sized squares for a few bucks.
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 :)
- ...
- 137 posts total
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! |
Hello Mulvening, I just went through this recently when I purchased a (new-to-me) Herron phono stage (I couldn't resist when it came up for sale recently). After getting it installed, I was having the same issues you are having. I spoke to Keith Herron about it,asking him about adding a resistor to knock those low frequencies out that are causing the problem. He talked me out of adding a resistor in the phono stage (which I had done on my Modwright) and just using an equalizer to get those low frequencies out. I ordered a Schitt Lokius unit, and even though it's inexpensive, is a very good little unit, absolutely quiet. I can recceommend it if your fix is involved around doing what I I wound up doing. Love the Herron, by the way. Regards, Dan |
Hi @mulveling It is no secret on the Gon that I have spent a lot of time over the years producing structures to support equipment and speakers. It was my loaning to a friend the AT616 Footers I continually utilise so they could experience suspended speakers, that made such an impression that they were prompted to try out an easier to acquire design, which become Townsend Bases and are now advocates of these. I am more very confident in suggesting them to be tried as I have first hand experiences of Townsend Bases in use and the benefits they create. We will have shared similar ambitions and intent, but our environments used for setting up the System are quite different to the one in your report. I started out on Concrete Floors and Concrete Ceilings with Brick and Plaster Finished walls. I am now using my Structures in an environment where there are Concrete Floors, Dry Wall Board Ceilings with Brick and Plaster finished walls. I also share the confidence you have expressed in the use of a foam, I use it as a Tier Material in a range of densities and even have one that has proven over the past seven years to be chosen over other options for materials that have a similar structural property. This foam is a product that is substantially compressed and weighs in at approx' 700Kg a Cubic mtr. As an up to date outlook, It does look like from now on Densified Wood is likely to supersede this Compressed Foam material in the positions it has been used. Many years ago I tried affordable footers, inclusive of Squash Balls, Spent Squash Balls collected from Sports Centres and Hockey Pucks (some will claim a Hockey Puck should be spent as well when used as a footer material). One other affordabe footer that might offer a further improvement is a Astronomers Tripod Footer, they are like a Hockey Puck but absorb energy that would cause the resolution of the Scopes reflections to be less sharp, due to energy transferral through the Tripod. I have really enjoyed the learning to be had over many years of creating structures, there is most likely a off the shelf short cut, but it will most likely come with quite a few 0000's in the price tag. Such a short cut will not allow for such investigations into how certain materials interfaced in certain ways can change a perception of how the audible qualities are effected. There is also the strong possibility the structures produced are performing as a close match or share parity with the off the shelf product. I will also mention Solid Tech 'Feet of Silence', used as a footer in direct contact with the Plinth of the TT in use, this footer has shown to be quite an attractive option in place of the AT 616. I am yet to discover a footer that has made the same impression as this one. There are designs of footer available that are variant of the FOS, and are much more affordable. One forum member who has contributed regularly to the Analog Section, has made it known in a previous post they use a variant design and are quite impressed with how they perform.
a |
- 137 posts total