Auralex ISO-Tone Turntable Isolation Platform

Huh? The pads are not for acoustic isolation. There're for vibration isolation. Hel-loo! Here's the blurb from the web site.

Product Overview

The Auralex ISO-Tone Turntable Isolation Platform is specifically engineered to decouple turntables from the supporting surfaces they rest on. The ISO-Tone diminishes structural vibrations and commonly associated acoustic feedback associated with desktops and DJ cases. Designed for turntablists, mobile DJs, audiophiles, rental houses and anyone seeking enhanced turntable performance, purity and accuracy, the ISO-Tone features a 0.75″ layer of black fabric-wrapped MDF that floats on a layer of Auralex’s proprietary Platfoam that protects turntables from unwanted vibrations. The 17.75″ W x 14.25″ D x 1.75″ H isolation platform accommodates most turntables and the low-profile design enables easy transport.

The sound of the system playing produces the vibrations that you are isolating against. There might be other sources of vibrations as well but typically that is the big one.

There, that was not so hard was it? :^)

At least we agree it's not acoustic isolation. ;-)

If you are a DJ and the woofers are pumping, those sound waves are going to vibrate the TT platform. That was my meaning of acoustic vibration and feedback; an external cause of vibration.
Obviously I failed to properly explain it.

3 Hail Marys and an act of contrition for me.

But we are not DJs. The primary problem is seismic vibration, the very low frequency stuff, below the frequency capability of speakers.