These platforms have been more effective than I'd hoped for my bottom ported Zu Omen Defs to eliminate floor vibrations. They were (I think) developed originally for studio monitors that sat on desks and consoles.They are available in multiple sizes and consist of two inches of polyurethane foam, a heavy steel plinth,and neoprene rubber on top (non skid grip).The 17" x17" I bought were $299 each.For those on a strict budget you could fashion a close facsimile except for the steel. Substituting mdf wouldn't prevent the recoil 100% as well as the steel that curves around the front.
My listening space is the living room in a very old home with wood walls,wood floor over a basement, and even wood ceilings. I do have GIK room treatments and foam decorative tiles on the ceiling.
What I was hoping for was to tighten the bass and eliminate a lot of the vibration that transfers to the floor. What I got was so much more. Not only did the bass tighten up significantly, the entire frequency spectrum cleaned up and became clearer. The only way I can describe it is like all of my music has been remastered and cleaned of noise. I'm now thinking seriously of purchasing more for my subs,which would've been the best place to start but I knew the bottom ports on the ZUs needed to be addressed sooner or later.
The music I listened to isn't really significant as everything was simply clearer and cleaner no matter what instrument or vocalist.My best CDs from Analogue Productions and MoFi - Otis Spann,Janis Ian,Pink Floyd, along with the old blues and rock that I love - James Gang,BB King,Hot Tuna.
System: Cambridge transport, Audio Mirror Dac
Rogue RP1 preamp
Aric Audio Transcend amp
ZenWave cables
Custom rack RusticIndustrialMi
GIK room treatments
@fleschler @relayer101 this is what I posted on AudioCircle earlier today.There are a few more details I can add.Being afraid of scratching them up and making them unreturnable I had help tipping and *walking* my 100lb Zus in position. I taped the position on the floor knowing the platform would shift around. Piece of cake though! Only spent about five minutes per speaker. The drier sound mentioned in the video I was concerned I would not like at all if it detracted from the music, but now I understand what the guys meant and it's not a bad thing. Piano music for instance, it became distinct when a note stopped and started along with when the pianist applied the pedals for a lingering note. Just like it's supposed to.Textures and timbres are more distinct but nothing jumps out at me in an unnatural way. The soundstage is better with more air around each instrument.The bass is sublime. I think you guys would like like them and I recommend them to any Zu owners reading this. I ordered mine from B&H Photo and they were delivered in seven days.