Vito w639 annoying buzzing

[James5969]

Is there any car/van audio people in here?
I’ve fitted new door speakers, rear speakers and a bass speaker in the Vito. I’m running the 4 speakers off a 4 way amp and the bass speaker off a mono amp.
Very simple setup but I’ve got an issue I can’t seem to figure out.

I’ve made a video for ease of explanation, but I can’t seem to post it here. Basically I’m getting a buzzing through the speakers, even with the HU off. Ignition on, engine off. Doing things like pressing the window switches, indicating, hazard lights all change the pitch of the buzz. I think it’s something to do with how the HU gets it’s power as it’s not the usual 12v red wire.

I also was getting alternator whine with the engine on, but I’ve fixed that with better ground points.

Anyway, any help/ideas very welcome.
Also if anyone knows how I post the video, I’ll do that too.

James

 

[Dodipops]

Might have to disconnect one speaker at a time to see if the buzzing stops?

 

[James5969]

Might have to disconnect one speaker at a time to see if the buzzing stops?

The buzzing is coming out all the speakers, but I’ll try that tomorrow to see if it isolates the issue, if the rain stops.

 

[James5969]

Figured it out today, although I don’t know why it was happening.

So I’m running 2 amps, the input from the HU was going to the mono amp, then I used its outputs to give the 4 way it’s signal.
For some reason this was the issue. As soon as I swapped it round so the 4 way was getting it’s input from the HU, and the mono is getting its input from the 4 way, the buzzing/static/noise has gone.

Not sure if this is normal or just my mono’s outputs are noisy, but .