Damaged audio quality after exporting iMovie using QuickTime (for short music videos)

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Damaged audio quality after exporting iMovie using QuickTime (for short music videos)

I have used iMovie in the past successfully to create marketing videos for my business. Utilizing photos and voice recording only.

However, this time I recorded high quality music videos at a concert (with iPhone 13 ProMax) and created 6 projects using clips from songs, overlaying titles, etc. I kept each video/project around 5 minutes for easy sharing. They sound PERFECT when I replay in iMovie, but once I export to Quicktime, the audio is DESTROYED. Meaning, there is severe static and abrasive sounds coming through. So much that I immediately changed the audience to private on youtube because I was mortified. I will not share until this is fixed, it's horrible and a disservice to these artists!

I tried exporting to various qualities to no avail.

My final attempt was:

Resolution: 4k

Quality: Best

Compress: Better Quality

This turned out to be 22GB. It still sounds like garbage! What is going on?

It is NOT a YouTube issue because I tried to play them on my computer first and they sounded terrible.

I'm running Big Sur version 11.6.5 on a Mid 2015 Macbook Pro. 16GB Memory

My hard drive has 65 GB available of 500.

I was getting a message during the creation of these that I had no disc space available. So I cleaned out old projects and this should have taken care of it. Again, the movies play perfectly in iMovie, but once I export using QuickTime, Audio is totally degraded to junk. Video looks pretty good, I did not analyze that too much to be honest. The sound is most important since it's music.

Please help!

Should I start over again?

MacBook Pro 15″, macOS 11.6

Posted on May 20, 2022 8:24 PM

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Answer 1

Top-ranking reply

Jenniferiphone6LA Author

Level 1

16 points

May 24, 2022 4:05 PM in response to Rich839

It turns out it was due to one of the optional audio settings I used in iMovie. For audio options I set it to 'music enhance' because it was live music concert footage so just assumed this would be the best.

Apple Support screen shared and pointed out the red and yellow sold lines running through the blue sound bar display at the bottom. (see attached pic). This is bad I guess. He said the music festival obviously had such superior sound and volume coming through that to enhance it any further actually created a kind of blasting effect. So when I exported to the highest quality in QuickTime, it exaggerated the sound even more and created major distortion/blow out/crunchy sound.

I tried flat, voice enhance and hum reduction, all which worked better for live concert recordings. I finallly settled on voice enhance which turned out to sound the best. I never thought to test every possible setting. Every recording I guess will be different so test and avoid those red bars in particular.

Still learning iMovie, it's pretty new to me.

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Answer 2

Rich839

Level 8

48,476 points

May 21, 2022 9:13 AM in response to Jenniferiphone6LA

Hi,

Hard to tell what is causing the distored audio. I can give you a few things to try to see if the problem can be isolated/cured.

Sometimes when the export function isn't working properly deleting/resetting preferences can cure it. To delete/reset preferences, open iMovie while holding down the Option and Command keys and select to delete preferences in the box that appears. iMovie will open in a new library. Reopen your old library to get back to your projects. Deleting preferences is a safe procedure that will not cause data loss or disruption to your project.

Another thing you can try is to copy your media into a newly created project and see if that cures the problem. To do

that, do an Edit/Select All, Edit/Copy, of the media in your project and then Edit/Paste it into the newly created project.

Sometimes re-encoding can cure sound issues. Try converting your exported movie to H.264, Mp4/AAC with the free

download, Handbrake. Do that even if the codec already is indicated to be Mp4/AAC.

You can get Handbrake here:

https://handbrake.fr/

A simple way to do it is to open Handbrake and do a File/Open Source. Navigate to your video and choose it as the source from the resulting screen. Then do File/Start Encoding. Wait a couple of minutes for the conversion to complete. Handbrake will render by default an Mp4/AAC clip. Then save and import the converted clip into iMovie.

You don't need to export at Best Quality (pro res) unless you don't mind the huge file size. Best Quality is really more for professional editing.

What happens when you export other audio with iMovie? Still distorted? Have you tried exporting an audio-only file (a Format option in the export box). You can choose aiff, wav, AAC and Mp3. The aiff and wav formats are lossless. See if you get a good audio export with only the audio.

-- Rich

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Answer 3

Rich839

Level 8

48,476 points

May 22, 2022 11:17 AM in response to Jenniferiphone6LA

I confess, I have no idea what is causing the audio to be degraded on export. Have you tried redownloading iMovie from your account purchases list in the online App store?

If Handbrake says "no valid source found" that usually means some odd format is involved or perhaps the file was an audio-only file, and not a video.

You could try resetting the System Management Controller (although not available for M1 silicon chip Macs):

How to reset the SMC of your Mac - Apple Support

See see what the Apple support techs say.

-- Rich

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Answer 4

May 21, 2022 9:36 PM in response to Rich839

Rich,

I tried all of the above (deleted preferences, made copy, tried Handbrake and exported audio file) and they all failed. Your directions were super clear, which I appreciate. I learned a lot, but it did not work.

I downloaded Handbrake and after clicking "open source" and then the iMovie application, it said "no valid source found". (see screen shot)

I also exported audio only to AIFF format and played using Quicktime. It sounded like garbage too.

No idea what else it could be. Must have something to do with disc storage messages I recieved from before the export.

Perhaps everything was being recorded in a backup file? Or the cloud? One of the original videos (which I decided to let go of and not worry about) had a missing file message on it. The video went black and would not play. I deleted the empty video file and moved on. There were some funny things happening BEFORE I exported anything. I deleted files and created space before I exported one movie from iMovie so thought it had been resolved. Maybe not? I think I should call Apple Support.

Jennifer

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