What room treatment product have transformed your room or audio system?

NMM thanks for mentioning ASC Isotherm. I have been looking at them for quite some time. seems like a good advance.

I did get to hear a demo room using active bass cancellation as the last NY Audio show, which I’ve always wondered about, but stupidly I forgot to ask them to turn off the devices to hear the effect. I can say that in the room next door the bass leaking through was overwhelming, since it was not cancelling bass at that location, but seemingly adding it.
Different topic but getting the speakers really far out into the room is extremely important, and also listening in mid field can give you a sense of what it it sounds like to get the room further out of the equation.

I’m not sure exactly what I’m getting at, but a friend used to host a series of live acoustic jams in his good sized apartment. They got fantastic musicians and David Grisman even showed up and played at one. I used to use those events to fine tune my ears (sometimes closing my eyes) to hear what live music from up close in a domestic setting sounded like. The sound and room colorations varied based on my position and players position, just like a stereo would.

The thing that struck me was that no matter the room interaction, the timbre and signature of the live instruments didn’t seem to change even though the room reflections did.