"Scott Dorsey" wrote in message
...

If you have a big room mode at 20 Hz, and you put an absorbing device
tuned to 35 Hz into the room, you've just made your problems worse and
not better. Just throwing in traps without figuring out where the
problems
like is not a solution.
--scott

This really deserves emphasing. No matter how crappy your room is now you
can always make it crappier. Either fix it right or leave it alone.