Hey,
For anybody that knows bmw audio and subwoofers/amps in general; please help!?.
I got a 12" jbl gto subwoofer put into my trunk and yes i have logic 7.
Its good BUT when i turn the gain up it ridiculously vibrates, when i turn it down vibrating is gone but no bass in the audio. The installer says that this is normal as i have a stock deck (i drive) :( .I cannot shut off the amp/sub from the front button but thats alright as i got a switch put in at the back, but the vibrating is so crazy that u can feel it in the cabin kinda like a massage?

So i was wondering if somebody could shed some light on this?

Loose panel, take it to the dealer, they should fix it...

Well there are a couple of things I read in your statement, which would only be guesses on my part. A good member to PM is Bruce Miranda as he is really knowledgable on the subject. First off you should know the trunks of the E60 is really well insullated, so whats probably happening is in order to hear any real bass improvement you are having to turn the gain up pretty high to overcome how good the insullation is for the trunk. Also another issue possibly is the box your 12" woofer is enclosed in may be too small for the amount of gain your are applying to the subwoofer which would then also cause disstortion in the bass response and finally are you sending only a low frequency signal to your woofer. IE are you using a cross over or does the amp have one built in, so you are getting a clean low signal to the woofer?

Any of the above could be causing your problem. Aside from the obvious when you add a subwoofer you are naturally going to add "vibration" to the car, however if its an unpleasant vibration then you have a problem.

Simplest way to figure things out is

1st - Confirm your box, woofer and amp all can work together and the limits are set correctly. If youre overpower your woofer or your box is too small thats an issue.
2nd - try turning the gain down to a normal level an folding down one of your rear seats so bass will pass into the cabin, again it may be an issulation issue

the second step is an easy test.

Finally I am not sure who wired your system up, but if they were smart they would have wired your remote wire to the factory amp so the amp would turn off when the car turns off. Sounds pretty ghetto to me that you'd have to put a switch in your car to turn off your amp. If one day you forgot to turn off the switch you'd be screwed.

GL

hey vishwen, is that JL sub in your sig pointing thru the ski hole into the rear passenger compartment? sweet idea, how's the sound?