Possible to edit device ID for the Cinema Displays (dual)?

[Wolfie81]

Ill explain why this is an audio issue for me...

Ive got 2x 27 inch Cinema displays and the graphics side of things is fine but not the audio. These monitors run audio through their Display port cables.

What Ive noticed is that when I have 1 monitor attached, the LED CINEMA DISPLAY settings in Audio works fine..
When I have two attached, I have 2x LED CINEMA DISPLAY options... but the first one loses the sound. The audio bar up/down now moves silently. As soon as I disconnect one monitor again... it reverts back to sound.

Im now starting to suspect this may be an Device ID issue as both monitors have identical DEVICE and ROM ID and OSX is confused as to what to do...

Any advice or guides in how to change the Device ID's for these?

Thank you.

 

[toleda]

Device ID's

Nothing to do with device_ids, different graphics names/ACPI edits required.
DP audio, see Post #1/HDMI Audio AppleHDA
USB audio, also supported.

 

[Wolfie81]

Thanks Toledo. I followed that page audit appears to work for now, but I'm now having 'display audio' setting issues..

The sound becomes crackly when I select it. This is important as the usb independent speakers (whenever I decide to turn them on) also become crackly. Is this an usb audio issue?

Thank you

Ps: I can't activate my independent speakers even if I just select LED CINEMA DISPLAY. To activate my independent speakers I must select 'display audio' though it gets crackly.

 

[toleda]

Is this an usb audio issue?

Yes.
DP: see II. Problem Reporting, Post #1, HDMI Audio AppleHDA. Post to thread linked.

 

[Wolfie81]

I've posted in that thread. Thank you.