@mulveling
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!
