IMO, you wouldn't gain much going to another sub period, your Hsu is a very good sub. The best money is now spent on upgrading the center or Mains, not that you will here much of a difference there either but it would be more noticeable; too bad the VP180 won't work for you.
If you must change something (I just noticed you are running QS4's), there is a noticeable difference when moving to the QS8's from the 4's, so perhaps this is where you could improve your sound, or did I miss the reason for not being able to upgrade them.
Last edited by jakewash; 03/11/11 04:44 AM.
