Hum From Speakers From iPhone

[Nick Hughes]

Ever since I did my audio upgrade, there is a hum in the speakers, but only when nothing is playing and my iPhone is connected via USB.

Any ideas what could be causing it?

 

[giroux68]

mine does it with my phone in the aux input and the power usb connected and the battery charged. battery below 100%..no hum.

 

[Nick Hughes]

Mine is just lightening port to USB connection. Battery is essentially always 100% since it charges at the same time.

 

[Bruce]

It is a ground loop. Eliminating it will likely be difficult if possible at all.

 

[Nick Hughes]

@Mainah We have similar setups in similar boats, do you have this issue?

 

[Mainah]

Can't say that I have noticed that in my boat. I highly doubt it is a ground loop. Possibly a line level circuitry issue in either the head unit or amps that is being amplified.

 

[David Analog]

The noise makes sense. You have two audio components interconnected that operate on two different DC voltages. The equipment interface should provide adequate isolation but it doesn't. I don't like ground loop adapters because they are a Band-Aid that leaves the true cause intact, and they can also alter the audio quality. But this is the type of application where a GLA is often the right solution. So if there is a way to convert from 3.5mm to RCA via any means, then you can try introducing a GLA to interrupt the flow of DC and stop the noise. Worth a shot IMO.

 

[paratrooper39]

I have the same hum in my speakers but overall it isn't so noticeable that I have done anything about it. I was also given the same advise as above by one of my engineers if its worth anything..