Auralex Great Gramma... yes or no?

What's under the carpet? If it's a solid floor of some kind, I don't see the Great GRAMMA yielding a big improvement. I use mine primarily in a live setting. Most stages are hollow plywood construction, and my Avatar 2x12 cab tends to be very boomy when sitting on that kind of a surface. The Great GRAMMA decouples the cab from the floor and tightens things up nicely. On solid floors, the difference is not noticeable.

 

I put them under both of my cabinets and they tamed the low end rumble alot. My amps sit on rugs & hardwood floors in an older house and could literally rattle the walls at high volumes...

 

I think they do affect the performance of the amp, even if you're on a solid floor with carpet. I think the effects you'd likely notice are more focus and punch. When I last recorded the engineer seemed glad I brought it, and that was a concrete floor with carpet. I dig 'em. Live, they really help a ton.

 

I notice a small but positive improvement on heavily carpeted floors and a big improvement on everything else. I just use them under all my cabs and combos now regardless what the floor is made of.

 

Most music stores carry amp stands and they're usually pretty inexpensive. Any of these will decouple the amp from the floor sufficiently for recording.