Humming subwoofer

[ajcelliott2011]

So I went left my car today to pick something up then came back to my car ( I had left it running because it's cold) and when I came back my phone wouldn't reconnect to the Bluetooth on my head unit and my subwoofer was making a humming sound. It's very strange. Never done that before. And very annoying. I fixed the Bluetooth issue by turning on and off my phone but as long as the head unit is on my subwoofer now has a low hum. Even when music is playing. Is it a grounding issue? I have a pretty good ground, I drilled a hole into my chassis and used some grounding nuts from my work to hold it down (I build control panels for automation systems, but car audio is not my forte). It's hard to get to the ground so I have not checked it yet, I first wanted to see if that is a possibility that could be the issue or it it is a voltage issue. I know in home subwoofers that is often the issue.

Sent from my LM-Q720 using Tapatalk

[Chris from Washington]

So I went left my car today to pick something up then came back to my car ( I had left it running because it's cold) and when I came back my phone wouldn't reconnect to the Bluetooth on my head unit and my subwoofer was making a humming sound. It's very strange. Never done that before. And very annoying. I fixed the Bluetooth issue by turning on and off my phone but as long as the head unit is on my subwoofer now has a low hum. Even when music is playing. Is it a grounding issue? I have a pretty good ground, I drilled a hole into my chassis and used some grounding nuts from my work to hold it down (I build control panels for automation systems, but car audio is not my forte). It's hard to get to the ground so I have not checked it yet, I first wanted to see if that is a possibility that could be the issue or it it is a voltage issue. I know in home subwoofers that is often the issue.

Sent from my LM-Q720 using Tapatalk

Hi Welcome to the forum
Is the humming noise present with the engine off or only when it's on?

[ajcelliott2011]

Sorry this took a bit to respond. The humming had stopped for awhile and now it's back. I just noticed today that it is only humming when the vehicle is actually turned on and the alternator is running. It makes me fairly sure it is ground noise. I have a decent ground for the subwoofer. I drilled a hole into the chassis of my car with a self tapper (after removing the paint in said spot) and also used a grounding nut on my ground. This humming didn't start until after I had had some electrical problems with my car and had had to remove the head unit. When I put the head unit back in, the humming didn't start right away, it started about a week after. It's driving me crazy. I actually unhooked the remote wire on my sub and have been driving I silence the humming was so obnoxious. I'm wondering if the grounding issue is in the head unit? Did I somehow mess up the ground when I put it back in?

Sent from my LM-Q720 using Tapatalk

[Chris from Washington]

that does sound like a grounding issue.

How long is your ground wire?
How about your RCA wire, is it ran along side the remote wire? If so, try moving them away from each other.

It could be caused by the deck itself. Do you have another deck you could try just for troubleshooting?