[stew]

Hi,

My speakers sit directly on the hardwood floor, and the floor is fairly resonant at certain bass frequencies. To decouple the speakers from the floor, I ordered some of Herbie's Giant Fat Grounding Bases. I have inserted these, and there is a distinct reduction of floor vibration! If I had to quantify, it would guesstimate something like 50% reduction of floor vibration; the result has been more clearly defined bass tracks and a slightly more coherent soundstage (midrange clarity?).

However, some coupling to the floor is still happening. So, my question is: is there another product I can use under the grounding bases to further help decouple the speakers from the floor? Poking around the website, possibilities could include any of the various "fat dots". Any input?

Thanks, Stew

[mshan]

http://www.auralex.com/c_sound_isolation/c_sound_isolation.asp

Don't know if you would need to put a piece of MDF on top to minimize any voicing Auralax may have done for intended application, but may be worth a try.

[Herbie]

Hi, Stew. You can't completely decouple from the floor. If you were to decouple the speakers absolutely from everything, the cabinets would vibrate wildly from the inertia of the drivers, with terrible sonic result. You need a firm reference to keep the speakers in place, which is why a resonating wood floor can be so problematic.

Some weight on top, like a granite slab, should help control cabinet vibrations. The cabinet-to-floor interface might be okay as is if you're getting good sonic results. To further reduce vibration transfer to the floor though, one of the best ways is to make a sandbox filled with a couple of inches or so of playground sand. Set the cabinet, with the Giant footers, on the sand, or, even better, place a plinth or platform (thick MDF is fine) on the sand and then the speakers/footers on the plinth.
 
Steve
Herbie's Audio Lab

[stew]

Hi Steve,

Thanks for the quick follow up. I understand your recommendation, but unfortunately consideration of WAF will prevent adding anything bulky (like granite slab or sandbox) between floor and speaker. I may then content myself with the current improvement and turn attention to a WAF-acceptable corner bass trap to help room interactions further

Thanks again, Stew

ps - I have also used the tenderfeet under my tubed preamp, and experienced a further delta improvement in soundstage coherence. Before adding the tenderfeet, I could thru my hand feel vibrations transmitting from the stand into the preamp. Now, the preamp "feels" fairly quiet. I plan to order some more and try under the cd player and amp!