t.akustik ISO-Pad 8

I got these for my studio. Decent sounding control room, hi-end monitors on heavy, top quality stands. There was no perceived improvement whatsoever using these ISO-pads.

So I brought them home instead. Poor sounding room, cheaper monitors on a wooden shelf, basic home recording setup where I mostly do editing/arranging using headphones. In this scenario the ISO-pads actually did something useful by reducing boomy resonances from the shelf. Obviously the ISO-pads didn't fix my poor sounding room but the sound actually got slightly more focused, less boomy.

My conclusion is that these ISO-pads won't do much in an already good sounding professional environment but depending on the setting they may do something useful in simpler, compromised setups, like home studios, etc. Basically, if you've got a problem with boomy resonances leaking into the surface beneath the speakers the ISO-pads may give you a slight improvement. But if your problems are caused by room resonances, don't waste your money on this, get room treatment instead.

You can definitely find thicker foam for your speakers with a little bit better decoupling, not by much but still better.
I'm putting these below my Tannoy Reveal 802 monitors, and the foam with the top piece is adequate.
However, as soon as I want to angle the monitors the foam would be too thin for complete decoupling in the front, and I'd still get vibrations on my desk when the monitor is angled. I still do when it's not angled, but it's not as excessive.
Though, if you don't care that much about that little extra percent of decoupling and/or you're not going to angle your speakrs, then you'd be fine with the t.akustik ISO-pad. If you do, then look somewhere else. Get something thicker that would perserve the decoupling even when the speakers are angled.