sub issues

2001 BMw 325ci

stock radio, Keenwood  7201 amp, fos cap,

Here is my issue, the BMW has a stock woofer behind the rear seat, I disconnected and removed the woofer, used the wireing for the lines in on the amp. (1) bridged the amp to 460 rms @ 4ohms, gain set @ 1, wired into a 2.00cu. ported box, port length @10.25 @ 35 hz, kicker 12L7 2ohm DVC wired in series for a 4 ohm load, my sub is now toast. double checked wireing and was to specs. previous I had a memphis that is also toast, and a JL, My question is could the stock wireing cause these subs to smoke up? Help.

elimitate you gain setting by putting it to minimal, as well as your crossover. Upgrade all wiring to 4 guage, for both power and ground. Your ground should be less than 3 feet. After this is all taken care of, install new woofer and adjust crossover and gain according to you ear, but be careful no to exceed their specs.

Uh,"adjust crossover and gain according to ear"?  This is not the best advice without explaining further.  Start HERE to learn how to set gain.  I highly recomend reading all that the Basic Car Audio site has to offer.

When you say your sub is toast, what exactly do you mean?  What is the make/model of your amp?

And how did you determine that "gain set at 1" is proper?  I bet this is the problem: your gain is incorrect and the amp is clipping like crazy.  I suggest you turn that bass boost off and set your gain properly, especially since you are using a high-level input to the amp driven by the factory sub amp (if I understand your setup correctly.)  Do you need instructions on how to do this?

Also, does your amp have a sub-sonic filter?  Where's it set?  You have a ported enclosure tuned to 35Hz; you will need to high-pass that at about 30-35Hz to protect the woofer from over-excursion.  This might also be part of the problem.

thanks that would be of great help. I have tried to locate a sub-sonic filter and they looked at me crossed eyed. I am only using the crossover built into the amp. How do I identify "clipping".