[shuteye]

So here's a question - with an open bottom, downfiring sub such as the Titan II LE, sitting on a cement slab with brass points installed, will there be an audible difference if sitting directly on carpet vs. sitting on some other material placed on the carpet (granite slab, hardwood cutting board or some such)? 

[shuteye]

Or what if you cut the carpet out right under the sub?  Mama says , if it sounds better I say , can't see it anyway.

[MLS]

Try a tile under it before you cut the carpet.  My 2 cents

[Phil A]

Try a tile under it before you cut the carpet.  My 2 cents

I have tiles under my Rels on top of the carpet.

[shuteye]

Excellent idea!  We have left over 12X12 tile from when our house was built (I was only kidding about cutting out the carpet).  Just curious, Phil - what was the difference?

[Mike Dzurko]

The wavelength of 80Hz is 14'. Carpet will have no absorptive effects in the bass range. Very little absorption until treble range actually. Any absorption will be of the high order harmonic distortion components from the sub. What some sort of heavy slab might do is increase stability.

[BobM]

I have a downfiring REL Strata III, which is similar enough to the Titan to be relevant. I found I had a dramatic improvement in performance by turning the sub upside down on the carpet so it is firing upwards. I placed a 1" thinck piece of wood on the upturned feet and placed something heavy on that to weigh it down.

I had to trun up the gain on the sub a hair to compensate for this, but the bass is definitely more tuneful and tighter overall. Give this a try before you do anything drastic to your carpet.

[shuteye]

The wavelength of 80Hz is 14'. Carpet will have no absorptive effects in the bass range. Very little absorption until treble range actually. Any absorption will be of the high order harmonic distortion components from the sub. What some sort of heavy slab might do is increase stability.

Which I already get by pushing on each corner of the Titan until the brass points penetrate carpet and pad.  Thanks for the clarification, Mike.