lessloss blackbody

While a certain amount of skepticism is always healthy I would point out that the naysayers here have not even seen one of these things. How do you know that they cannot work?

Quite different from, I tried several out and in my opinion they had no effect or their effect was minimal at best.

Yes, 3 possibilities:
1. They work, positive effect.
2. They have a negative effect.
3. They do nothing, they have no effect.
Unlike the last thread on these, there are reports from actual owners. So far the owners are reporting option #1.

I wonder if they work for all sound or just sound that comes out of speakers?

Might they work for say a live vocalist, piano, or guitar player and make them sound better as well I wonder?

If so they should use them in the recording studio and lick the problem at the source.