ive had alt whine since i installed the system. redid grounds check everything turns out the whine is coming from the rear tweeters. its weird. its minor enuff to not make me give a shit anymore

 

I had a 13.5 W7 with a 1000/1 amp in a custom box. I had the sub facing into the cabin. But I had the ski port (ski port is very important). The system was insaneeeeee. Many people can vouch for this, IT hit so hard that you can see the roof flex when the beat dropped. There was absolutely no rattle... no dynomat or any other sound deadening used.

 

The whining is not your alternator, it called engine noise , you can google it. It means that the power wire is too close to the RCAs and is creating interference. The power wire and the RCA should only intersect at 90 degree angles

 

I thought it was a bad ground getting electric interference?

 

Bad ground can cause whining/engine noise. A sign of a bad ground usually is a pop of the sub when the amp turns off. In most cases engine noise is cause by the power/RCA situation

 

I did what OP is asking. The bass sounds great through my DIY hatch in the rear seat.
However, there's still something inside the rear deck that rattles if I play the sub very loud (but the bass doesn't sound good then so it's irrelevant).



- Antti -

 

How did you guys go about cutting the ski pass-thru out? Angle grinder? Recip saw?

I don't mind cutting it out, but I'll put some black speaker grill fabric over the hole so it doesn't look too hoopty!

 

I had the ski port on my E60. but when I had a E46 I cut the port, with an angle grinder. came out perfect.