There's a better solution for about the exact price of 4 ASC Tube Traps ($3,200). It's called the Audio Kinesis Swarm distributed bass array (DBA) system,it was mentioned earlier on this thread and it's a much more elegant solution than bass traps. It provides near sota bass performance in virtually any domestic sized room and integrates seamlessly with virtually any pair of main speakers, regardless of main speaker type (dynamic, planar-magnetic or
electrostatic).
I have the DEBRA which is basically the same as SWARM. As Noble mentioned, it entirely got rid of the bass problems in my room. I went through subwoofer or no sub and tried up to 2 subs, but this is the ticket people! Best money I spent on my system so far.