audio routing issue

Hi everyone,
client has two MacPros one they installed out of the box, one I clean installed. One the one they installed I have an issue with audio routing from FCPX: Any clip that is flagged as Mono is not routed to the audio out but shows on FCPX meters. Any stereo clip is routed on the mac's audio ports.
If I turn a dual mono clip into a stereo one I can hear it. If I activate the Pan stereo on a mono clip and pan either left or right i can hear it. middle position is dead.

MacPro is on Sierra and I looked into the MIDI settings which look ok. Furthermore if I import the xml from this library onto my MacPro everything is ok.

I hesitate to do a clean install (I HAVE had bad factory OS installs in the past) if there is an easier solution or if it proves to be something with the hardware.

Any help is welcome

Patrice

Hello Patrice,

If the audio from the same project comes out OK on your Mac, this is clearly a settings issue on the other Mac.

The MIDI settings should be set like this:

- Open Audio MIDI Setup.
- Select your audio output device in the audio device list.
- Click Configure Speakers in the bottom right of the window.
- Click Multichannel.
- Choose Stereo from the pop-up menu and click Done.

Can you confirm that the settings are like this?

If the settings are okay and they are using an external audio device: connect the audio device to your Mac to see if the mono audio comes out properly. If it doesn't, this means there is a setting inside the hardware that needs to be changed.

- Ronny

Hi Ronny,

yep, been there, though the MIDI panel in Sierra does not say Multichannel anymore but offers Stereo or Surrround 2.0.

Client does not have an audio device, this is trying to connect straight from Line level out (speaker icon) and the same happens on the headphones out.

I'll look into into further tomorrow and keep you posted.

Patrice

Hi everyone,

had a further look at the issue today and here's what I found:

- Creating a new library with a new project and new clips does not change the situation
- Turns out that not only FCPX is affected but all sound producing software
- Suspecting a bad account I created a new admin account, to no avail
- in the Audio Midi utility when clicking on the speakers (which usually produces a sound that helps in confirming your setup) I get ear-scratching noises but no clear sound)
- apparently only line out and headphones out are affected, internal speaker ok
- I did not have time to do a clean install on this mac but I am leaning towards a hardware issue but not entirely ruling out MacOS install
- Unfortunately Apple Hardware Dignostic does not launch on this machine, wether locally or internet (D or Alt-D at Launch)

What do you think?

Patrice

Hi everyone,
thought I would update this thread for whatever it is worth: turns out that the MacPro had a faulty audio board after all. Everything works after this was fixed.

P.

Had I seen your second to last post before, I'd have said hardware issue. I've seen these symptoms before. Glad you got it solved.

But brings up a good troubleshooting step. I even pointed this out on another thread about a color issue just now. If you have visual or audio issues, and basic troubleshooting steps don't work, open other apps, see if the issue shows up. If so, most probably hardware problem somewhere.

Patrice Freymond wrote: … turns out that the MacPro had a faulty audio board after all. ….

LOL (sorry, couldn't resist)

I sent a feedback to apple.com to add "check your hardware" to their list:
support.apple.com/en-us/HT203477

Actually this kind of sit eating MIGHT occur if its a dual mono signal, but somehow the phase on one side got flipped.

In stereo you would be able to here it, especially with headphones, might sound a bit odd though. However when combined as mono they would phase cancel each other out to get silence.

I can't imagine a situation where this would happen, but its handy to know these things just in case.

The phase thing is only true to generated dual mono (manually created in post), not if the original recording was dual mono. Audio recording circuitry recording the same mic to two channels handles this. It's been pretty standard processing for a long time.

Yeah sometimes cameras will record the same signal to both sides, so it's true in that instance as well. It's possible for a cable to be misfired, rare, but possible. Especially if you are using 3rd party solutions.

Otherwise it's something that is generally done in post.