I've made a diy version and it works. So, I would assume the real ones do too. Eighth Nerve does the same thing, and they've said that they haven't had a single return.
For the difference that it made for me, I believe it.
I'm kind of worried about the brightness in your small room though. I had that in a room for about a year and never solved it. I could absorb the room, but it would sound dead. The room tunes weren't enough to deal with it. Hopefully, others can chime in.
