Bob,
Glad to hear they had the same effect in your room as mine.
I am using 6 of the MiniTraps and I am considering getting two more.
I did experiments and added the MiniTraps in pairs to see how much impact each additional pair had. Unfortunately (for my bank account), as I added pairs things got better and better.
When I talked with Ethan he thought that 8 MiniTraps would produce the best results in my room.
My buddy (Sunshinedawg) took Ethan's advice and is building the MiniTraps himself. He also thinks that adding them makes a tremedndous difference in the quality of his system.
I realize that in real terms $360/pair + shipping isn't cheap, but I think it is money well spent and much cheaper than many other room treatment options out on the market right now.
George