Make one/have one made that is tuned low (31-32Hz is good IMO) and built well (I can make one for you if you'd like...PM me if you're interested)possibly. maybe the tuning is too high
How would I know if I don't know the tuning? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gifno clue. but is that the problem