Q: I can hear the Audio in Final Cut Pro X 10.2.1 Timeline but not in the Event clip.

Okay, I tried transcoding, although I think it was already optimized, and I still hear nothing on the iPhone video. Meters are showing audio present but I hear no audio. I do hear the audio on all the other clips.

I monitor with my PreSonus FireBox Interface. I made sure it was selected in the system Prefs Sound Panel. Just for grins, I switched Output to Internal Speakers and I can hear the audio. Then I switched back to my Firebox and no sound from the iPhone Videos thru Photos Video or FCP X . Once again, I do have audio for other clips in either the browser preview or the Timeline. This is driving me nuts.

The PreSonus Firebox has no metering of it's own. It's monitored thru Apps. You can see the Spkr Icon on the Menu tray and it's turned up. There isn't anything wrong with my interface. My iTunes plays back perfect, my Logic Pro plays back perfectly, and all other Apps play back perfectly. It's only the iPhone Videos that I imported. I also tested with Quicktime Player. It plays back all audio and video files perfectly. Quicktime also has not audio for iPhone Video either.

Okay after spending 2 days on this, I've finally solved the no iPhone audio problem. I want to thank you guys for coming to my aide. I really appreciate the help and response that I usually get from the Apple Communities.

I have searched and searched for solutions and I found it at: If you can’t monitor mono or dual mono audio from Final Cut Pro X 10.2 in OS X 10.10.3 - Apple Support

The following step was the actual solution:

Note: the step on switching from Stereo to Multichannel and Stereo was the answer. You also have to click the "left front" and "right front" spkr test. When you hear the white noise from each side, then you have configured correctly.

You can resolve the issue by following these steps:

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