I have a pair of SR4719X that have been barely used. One of the 2241H 18" drivers seems to "pop" or unload when driven fairly hard. This happens only on the very lowest frequencies (40 to 30 Hz) found in much of todays Rap music.

I am running a dbx PA+ processor with the low pass crossover set to roll off at 30 Hz at 24 db. Each cabinet is powered by a Crown MacroTech 2400 bridged mono and the cabinets are wired in parallel - 4 ohms each.

Any ideas to try or things to look at? Do I just have a bad driver?

Would switching to a MA 5000 running in stereo be a better choice for subs than the bridged MA 2400's?

Thanks in advance for the help.

Mike