MacBook Pro - HDMI audio interference on iPhone jack

[LCPepper]

I searched around on the forums to see if there was anyone having similar issues...

I have a Late 2013 MacBook Pro 13", when I have it connected via HDMI to my monitor and have my iPhone 6S charging from the USB port, then play music on my speakers from the headphone jack on the iPhone, there is audio interference.

Not a hiss, more like a grounding issue, not static, but like a grinding. Perhaps what "snow" on a monitor would sound like if it had a sound.

Unplugging the HDMI cable resolves this issue. I have swapped out the HDMI cables and the Lightning cables for brand news ones, and it's still the same.

This doesn't happen if the speakers are connected to the jack on the MacBook Pro...

Is anyone else having this/been able to solve it? Or should I take the MBP into Apple?

 

[Chancha]

It only takes one part of the chain ungrounded to let hiss through since your MBP is a central hub in this setup. I would suggest first to make sure the MagSafe is using an extension cord first, if it is directly using the 2 pegs then there's no ground, where the estension has a 3rd contact that goes from the metallic pin of the powerbrick.