Thank you so much for your sharing your detailed report! Very informative indeed.
I was wondering if you could share a link of the specific 3 layer rubber pad from Vibrasystems that you found to be so effective?
Thanks again and best wishes,
Don
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.
Excellent detailed post and a terrific contribution to the forum! Thanks! I also had a long thread on my trying out various solutions in building an isolation base for my Transrotor Fat Bob S turntable. It's amazing how similar our conclusions were! First, my sources are all in a separate room from my listening room. That's already a good thing in terms of reducing any influence from the speakers in the room on the turntable. But I had very little space and had to use my old Lovan tubular rack because it was narrow enough. But it's a pretty flimsy rack, not solid at all. Plus it was on a sprung wood floor and my tall son stomps around like Frankenstein, so footfall was an issue too. I bought tons of isolation stuff, testing it in all sorts of ways with vibrometer measuring apps, to see which isolated best. I tried sorbothane products, wall damping, isoacoustics, MDF, constrained layer damped metals etc. It was finally the Townshend spring-based Iso Pods that did the trick. They isolated waaay better than anything else. Put the isoacoustic pucks to shame. So I ended up with the turntable on a 2 1/2" thick maple butcher block (wanted that wood look). Then that sits upon a constrained layer combo of two MDF sheets, which sandwich a layer of steel with wall damp material on each side. Man, just that MDF/Steel/Wall damp combo is super dead to the rap test! Then under that I have the Townshend pods. The pods are really doing most of the isolation work. I can place my vibration app on the turntable and stomp all around the floor by the turntable and almost nothing registers. I was impressed enough with the Townshend pods to try the Townshend isolation bars under my speakers (which sit on a shag rug over a sprung wood floor). In that case, once again, the spring based solution clearly isolated very well. If I was playing bass heavy tracks I could feel the floor (and sofa) vibrating but with the speakers isolated with the springs, the floor was absent of any vibration. For me that turned out to be a good and a bad thing. The speakers did tighten up in the bass etc, but I actually preferred both the tone and the punchiness of the speakers just sitting on the floor. For my taste the springs isolated a bit too much and I lost some "room feel" in the bass. So I've been on to experimenting with tons of stuff under my speakers. I have the Isoacoustic Gaia 2 footers and I preferred them to the Townshend, since there were a 1/2 point - they isolated and tightened things up, but not to the degree of the springs. It's clear that I want *some* isolation effect but also some engagement with the room. So I'm trying all sorts of combos. This is where the hockey pucks come in! I actually replaced the Gaias on the front of my speakers with speaker spikes in to hockey pucks. I love the result. The pucks seem to keep things tight but still pass some level of vibration in to the floor, so the sound is also really punchy. I've tried a variety of other things too and still experimenting. Right now I've put a 1 1/4" thick granite bass beneath the speakers too. That didn't actually tighten up the sound much in of itself, but I like the look and will try to work with it. Anyway...thanks for sharing your results in such detail!
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@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. |