jbl b460 or jbl 4645c

You must be playing this speaker incredibly loud. You are probably clipping the heck out of your amp, or if your source is a phono you probably are getting subsonic frequencies fed-back thru your system and this causing some very low frequencies.

You need to either get a better amplifier or a better front end.

This speaker, if properly driven and amplified, should be able to re-create an earthquake in your house.

I also have the B460 sub. When it was new, I blew it twice. JBL handled the repair cost. Since then, I have learned to modulate the power and it sounds great. I would not use a different driver...Love mine...

i got a 4645c in my living room and it can generate an earthquake right across the street

I have a JBL B460 and a B380. Never a problem. I have a massive 95 pound amp bridged to 1500 true rms watts of power driving this subwoofer! JBL did not install a fuse in the B460 or B380 subwoofer speakers because they can take a tremendous amount of power and they did not want to limit the driver. There is a writeup by JBL in an audio magazine which I still have stating that they drive their B460 in their lab (at the time)with 2 kilowatts of power (2,000 watts!) and the speaker had never shown any signs of distress. In short, Lorr Kramer, JBL Product Mgr, and Greg Timbers, JBL's Senior Transducer Engineer, go on to say "in most cases the bass amplifier will reach its limit before these subwoofers reach theirs". (Audio Magazine/August 1983 issue). Your problem, gentlemen, those of you who have blown these speakers is that you bottomed out your anemic amplifiers and sent straight DC to the speaker. The 2245H 18" inch driver, as JBL states, was "designed specifically for low-distortion, high level professional bass reproduction." Read those two words back to me--HIGH LEVEL. A minimum of 300 watts is stated but 600 is much better. I would recommend no less then 600 true rms watts.