Audio distortion to Thunderbolt Display with new MacBook Pro

[WiLLGT09]

Hi all,

Recently got my 13" Non-TouchBar MacBook Pro, and I have it all hooked up to my desktop setup, which involves a 27" Thunderbolt Display and various daisy-chained external hard drives. I have my MBP attached to the display via Apple's TB3-to-TB3 adapter and power via the MBP's own USB-C power brick. Prior to this, I had the exact same setup, but with my 11" MacBook Air, with the display's dual power/display cable attached for power.

My problem now is that I'm experiencing audio distortion (like a crackling, static-y) sound from the TB Display's speakers. Used Spotify, YouTube. Both start playing audio fine, but eventually sounds becomes distorted. Never had this when my MacBook Air was attached. Spotify seems to play just fine out of the MacBook Pro's own speakers when sitting on the couch.

At first, I thought it could be my new UPS (power supply), but after taking that hardware out of the loop, I'm still experiencing issues. Had some USB items plugged into the TB Display's rear port (card reader, USB SuperDrive) and I unhooked those as well.

Could there be something wrong with one of the USB-C ports on my new MPB? Something with the TB3-to-TB3 adapter? Perhaps the fact that the old MagSafe power cord from the TB Display is now no longer in-use and is just hanging there? Some sort of grounding issue?

Thanks!!

 

[Weaselboy]

My comment does not help you fix this, but I have the new 13" Touchbar version and before my LG 5K monitor arrived I was using the same setup as you with the Apple adaptor and the Apple Thunderbolt display and I did not have this issue at all. Everything worked perfectly. So I think something is broken on your end.


I had it setup just like you with the new USB-C charger and the old Magsafe dangling in the air.

 

[WiLLGT09]

Thanks for the note. Very strange, indeed. Do you suspect something wrong with the new computer (or its ports) or the TB3/TB2 adapter?

 

[Weaselboy]

Thanks for the note. Very strange, indeed. Do you suspect something wrong with the new computer (or its ports) or the TB3/TB2 adapter?

I just don't know and would be guessing. Do you maybe have an Apple Store nearby where you could swap the adaptor just to test it out?

 

[WiLLGT09]

I do have Apple Stores nearby. I meant to buy a 2nd adapter anyway, so I could definitely try this.

I also stumbled across this TB Display firmware update: https://support.apple.com/kb/DL1775?locale=en_US It was released in November 2014. I purchased my display in January 2014, so it's possible I never installed this update. I certainly don't recall doing it. Would a display firmware be something that pops up in an Apple system/software update?

EDIT: Seems a similar issue popped up in 2012 with the TB display and the MacBook Airs: https://www.cnet.com/news/2012-macbook-air-plagued-by-audio-noise-with-apples-thunderbolt-display/ Bad driver issue. Perhaps there's a similar bug with the MBPs?

 

[Weaselboy]

Would a display firmware be something that pops up in an Apple system/software update?

Yes... it just comes up during a normal software update check, so you likely have it.

 

[WiLLGT09]

Well, I hope I'm not speaking too soon, but I seem to have mitigated the problem -- by unhooking all my daisy-chained external hard drives from the back of the Thunderbolt Display's hub. So far, I'm now hearing clean music out of the display speakers. Interesting. Again, this didn't occur with the MBA and all the external stuff attached to the display.

I do have one of OWC's TB3 Docks on pre-order, so perhaps this whole issue will be rendered moot as I'll have all drives attached to that.

Haven't yet gone to the Apple Store to get a new adapter yet.

 

[WiLLGT09]

Quick update: I went to the Apple Store and got a second TB3-to-TB2 adapter, and it still has the same problem.

BUT, I think I've narrowed it down to the Apple USB SuperDrive I recently attached to the TB Display's USB port. Given the lack of regular USB on the MacBook Pro, I had to switch to using the monitor's USB. I had all my HDDs attached & the SuperDrive, and I started hearing the same audio issues. After disconnecting the SuperDrive, everything seems great. Quite strange.

 

[WiLLGT09]

Well, I don't think it's *only* the USB SuperDrive Had all my hard drives attached/daisy-chained as usual, had Spotify playing and editing photos in Lightroom (photos on external drive). Audio was playing fine for a while, but then started stuttering again. I noticed Time Machine has begun it's normal backup process. So, not sure if this is caused by the FW800 Time Machine drive attached to the Display, or somehow the additional CPU load while TM is running (??).