popping sound at beginning of clips when in review

John thanks loads for this I am trying it now. So far though every time I have exported it to Quicktime, with volume zeroed or with audio extracted, the resulting clip still has audio. Im sure Im missing something simple here...

Danno - my apologies. I was providing advice based on my memory of how I had used QT to solve the problem. What I should have informed you was to MUTE the top video track before doing the export - NOT just to lower the volume and extract audio. I just did a test and all you have to do is mute track 1. On import from QT there will be NO audio in the imported clips.

I would still extract the audio before doing the export, so that you have it in track 2 ready to align with the new video if required.

Very sorry about my misleading advice - got confused about zeroing the volume versus muting the audio!

John

Danno - further to my last post, just in case you're not sure about muting - you need to uncheck the small box on the far right of the timeline (in timeline view). There is a box for each of the 3 tracks - it might pay to mute each of these tracks. They can be re-enabled, as required, after you've done the export/import.

John

Brian

Playing the clip on its own in the timeline also shows no sign of the glitch. It only seems to appear when the playhead moves over the division between two clips - whether that division is a straight cut or transition. Note that an audio fade in on the incoming clip (where no transition is present) can sometimes produce the glitch (pop), but is only heard as I described. Very aggravating!

John

Mark

Sorry it's taken a while to get back to you on your rather expansive post (a lot to take in) 🙂

Most - if not all - of your suggestions about the audio problems sound reasonable (pun intended). However, I'm not convinced that "filter audio", "recording at very high volume", "digital clipping", presence on "quiet clips", "too much strain", "loose audio" and/or "create new clip at scene break" are causative issues in regard to the audio glitches. All good suggestions nonetheless - and greatly appreciated.

I always check the preference to "filter audio on import" and "create new clip at scene break". Also, I always record at 16 bit (not 12 bit) - and still get audio glitches under certain circumstances.

It makes no difference whether the audio was loud or soft on the recorded video. Most cameras have inbuilt technology to adjust sound levels so that "digital clipping" does not occur. I always record with the inbuilt microphone and have never used an external on the camera.

iMovie should be able to comfortably handle all the "timeline and audio levels" and "constant rebuilding in the background" - other editing programs do - why not iMovie? The actions that appear to bring out the audio glitches are basic functions of iMovie and shouldn't, in themselves, initiate the problem - actions such as adding transitions, inserting stills before video, and audio fade-ins.

You may have hit on something with the "algorithm used by QuickTime in iMovie". I don't know enough about this to comment - perhaps other users may wish to comment?

Your comment on "loose audio" and the sound not being "locked to the video" is interesting. I always thought that the audio was somehow locked to the video on import to iMovie - it comes in as one track on the timeline and you are able to independently extract the audio from the video track. But again, I don't know enough about this to offer any insightful comment.

Thanks again for your invaluable post Mark - it all helps to throw further light on this vexing problem. I say - bring on an update!

Cheers
John

Hello Mark

I am trying the suggestion of the black clip. You mention that you mute the black clip. I'm at a loss to how you did this though?

Can someone please tell me how you mute a black clip?

Cheers

Alli

I've had that happen too. But when I then export the movie it goes away. I'd say try a "share" to export it as a quicktime movie and it will probably be gone in the quicktime movie. If it is, then it doesn't matter so much, since your final product isn't going to be an imovie document anyway. It's irritating all the same though during the construction of your movie to have to hear that.