aftermarket sub affects fm reception- how do I remedy this?
05-07-2017, 03:36 PM
#1
aftermarket sub affects fm reception- how do I remedy this?
I live in the Sierra Foothills, about 40 miles from most Sacramento radio stations. My 2006 TL (without Nav) got good FM reception when I first got it. I recently installed a 10" sub in a box with an amp in the trunk. Everything works great, but many weaker radio stations now get a scratchy buzz when I listen to them. I get no buzz with strong radio stations, or when I'm in town, and no buzz with cd's or mp3s.
I disconnected the sub amp wire from the battery and the buzz goes away, so I'm pretty sure it has to do with the sub wiring. I ran the sub amp power wire along the drivers side doors, under the door sill. The sub is wired to the stock sub speaker wires in the trunk, and I removed the stock subwoofer speaker. The car has tinted windows, but they were tinted long before the sub was installed and I still got good reception.
I thought it might be a grounding issue, so double checked my grounds. The ground wire for the sub/amp is connected to clean sheet metal in the trunk (I sanded away the paint for a good contact). I also added an additional ground wire from the battery to clean sheet metal in the engine compartment with no change, so I think it's unlikely to be a ground issue.
Do I need to separate the power wire from the wiring loom under the door sills? Can i just move the power wire a couple inches away to run along the floor, instead of up along the door sill? Do I need to run the power wire along the passenger door sills? There are a number of wires along the passenger door sills, similar to the driver door sills.
Thanks for any ideas!
I disconnected the sub amp wire from the battery and the buzz goes away, so I'm pretty sure it has to do with the sub wiring. I ran the sub amp power wire along the drivers side doors, under the door sill. The sub is wired to the stock sub speaker wires in the trunk, and I removed the stock subwoofer speaker. The car has tinted windows, but they were tinted long before the sub was installed and I still got good reception.
I thought it might be a grounding issue, so double checked my grounds. The ground wire for the sub/amp is connected to clean sheet metal in the trunk (I sanded away the paint for a good contact). I also added an additional ground wire from the battery to clean sheet metal in the engine compartment with no change, so I think it's unlikely to be a ground issue.
Do I need to separate the power wire from the wiring loom under the door sills? Can i just move the power wire a couple inches away to run along the floor, instead of up along the door sill? Do I need to run the power wire along the passenger door sills? There are a number of wires along the passenger door sills, similar to the driver door sills.
Thanks for any ideas!
06-04-2017, 10:13 AM
#2
After researching this, it looks like "class D" amplifiers like the one I bought can mess up antenna reception. I still haven't figured out how to remedy this, but maybe moving the amp to a different part of the trunk might help.
12-06-2017, 09:03 AM
#3
After leaving the car at the shop for a full day, and having them spend $200 worth of troubleshooting time, they came to the conclusion I told them originally - the class D amp was messing up the reception. They put in a different, non class D amp, and it fixed the reception issues. Unfortunately, the subwoofer doesn't sound as good with the replacement amp, but at least I get radio reception again.