subwoofer interfering with radio reception.
 

Local radio, not xm.

Anyone else experience this? When I first got the car, I got a lot of stations decently, now with the sub installed, I get only a few of the stronger ones, and the ones that no longer come in make a really weird noise, not like regular white noise.

It's not a huge deal, but has got me curious.

The antenna is in the back window,so if the subwoofer is vibrating the glass it very well could affect the FM reception.Also if the amp or power cable for the amp is near it,it could cause some induction.

That's interesting. Guess I won't worry about it, I'll be using XM, I think the last time I had the local radio on was 4 years ago.

Did you get your windows tinted also? Metallic window tint can interfere with the FM antenna reception.

Did you do the sub install or did someone else do it? You might want to check around under the rear window and see if they/you accidentally knocked the antenna connection loose during the sub install.

I've seen something similiar before. You probably put in another amp for the sub. Make sure it is grounded properly.

It's grounded properly, no window tinting, installed it myself. If I somehow knocked the antenna cable loose, I wouldn't even know where it's at to look.

It's not shaking the glass during testing, it's at low volume and it's not like there's much bass coming over the radio.

I have tested, and the interference gets worse when the sub comes on, I can test this easily since the sub uses signal sensing to turn on.

It's like it's trying to lock onto certain signals, and can't. Some signals are automatic, but there's one in particular I'd like to get and it's from a station probably 90 miles away and goes out only when the sub is on. There are likely others, but that one interested me the most.

edit: it's because I have a class D amp, does mode switching or something like that, causes RF interference, it's a jl 250 watt amp, anyone know of an easy fix?

you may have wired something wrong. send pics of your job.

another thing it could be a problem with your fm tuner. disconnect the sub and see if it still happens, what wires did you tap into and what signals did you get. if that amp has signal sensing you have to make sure its getting the right signal from the stock amp. the factory amp is located behind driver side rear bumper. have you messed with it.

so you used a hi low converter right?

Where are you pulling power from? Run a fused line direct from the battery to a power distribution block then amp. Might want to try a capacitor as well.

Bad ground

I agree with the bad ground...

Put a 0.1uF ( 20V or greater cap ) 12V to ground on your amp. Also clip ferrite beads to ALL wires connected to your amp.

This MAY fix it. The amp may have a problem, as it should not generate RFI if it is designed properly.

Re-check your grounds. The amp should be screwed to the metal of the car.

I don't know what a 0.1uf whatever is.

The ground is good, trust me.

Class D amps are known to cause this sort of thing, at least that's what I've read, google it if you want.

Keep in mind the amp is right below the rear window, where the antenna is located, which is probably why other people with class D's don't notice it.

The only good tip so far is the ferrite clips, though if you could be more specific about which wires, power, ground, rca, and speaker?