Over the past few days I've noticed my dcons bass excursion decline at random times and now it is at stable very low volume compared to how it used to sound. I've only been using it for a bout a year running on a crescendo 1000c4, it used to sound badass and shook my whole car up now its just a dull rumble. I don't think I blew it out because I've been running it at the correct wattage thru my amp and had it professionally installed and thought SSA was known for it quality woofers. can someone please help me out?

id pull the sub and give it a look. see if its still hooked up correctly or see if a wire came loose. have you messed with your settings on your amp?

Agreed, pull it and check the wiring. Also check it with a dmm.

Are you sure it's the sub(s) ?? Might want to have the amp checked out too ...

I agree, check all connections, something sounds screwy for it to die off like that.

Happened to me, might be the tinsel lead's starting to snap off

Any update?

As the others have said, you need to spend some time troubleshooting.....check connections and check the subwoofer with a DMM.