Distorted Audio Files

Question

Distorted Audio Files

I recently exported a number of tracks as audio files from Logic, but found that when I re-imported them (to check they were ok) some of the files (both real and software instruments/voices) were horribley loud and distorted. The original files were recorded using Garageband, and sound fine when played back. I get the same distorted result when importing them into Sonar too, so I'm guessing it's something to do with the original file. I've exhausted my limited knowledge on trying to find a solution or a reason for this so I was wondering if anyone else can offer any advice? Any help would be greatly appreciated. Many thanks.

MacBook Pro 15" 2.33 GHz Intel Core 2 Duo, Mac OS X (10.5.7)

Posted on Jun 12, 2009 3:12 AM

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Answer 1

Jun 12, 2009 3:16 AM in response to Phil Huddlestone

Do the waverforms of those files look unusual (like squareshaped with no really visible waveform amplitudes) or do they look normal?

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Answer 2

Jun 12, 2009 3:28 AM in response to Sampleconstruct

Squareshaped with no visible waveform amplitudes is exactly how they look. Just a mass of black through the whole track.

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Answer 3

Caramby

Level 4

1,523 points

Jun 12, 2009 4:15 AM in response to Phil Huddlestone

How exactly did you go about exporting these files?

(Of course, if these are supposed to be identical to the GarageBand files, then you still have the originals which you can use instead. But we still need to find out what happened…)

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Answer 4

Jun 12, 2009 4:33 AM in response to Caramby

The tracks were recorded using Garageband and the imported straight into Logic in order that I could export all tracks as separate audio files. The plan was to have the song mixed and mastered in a local studio who use Sonar. When they were imported into Sonar, that's when we found some of the tracks to be distorted. I re-imported the affected tracks into Logic, but the result was the same. Each attempt to export a 'clean' track has failed. I've tried tweaking a few parameters here and there, but to no avail. And yet the song sounds fine when played in garageband. No distortion, no peaking, nothing!

Many thanks
Phil

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Answer 5

Caramby

Level 4

1,523 points

Jun 12, 2009 4:43 AM in response to Phil Huddlestone

Okay, locate the GarageBand versions in the Finder & examine them in another Audio utility. If you don't have one, at least try playing them in QuickTime. Make a note of all the info you can find out about them. Perhaps they are in some unusual format for some reason…

Also try dragging directly them into the Audio Bin in Logic, & then opening them in the Sample Editor.

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Answer 6

Jun 13, 2009 12:14 AM in response to Caramby

Quick update. I have dragged the files to the Audio Bin and opened in Sample Editor, as you suggested. The file is still the same, but using the Silencer I was able to get a better, less distorted wave form, but too many stutters and peaks to be able to use the file. I will try examining them in another audio utility as you suggest. Many thanks for the help.

Phil

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Answer 7

Jun 13, 2009 12:17 AM in response to Phil Huddlestone

Try the iZotope RX demo - it comes with a very good declipper - maybe that will make some of the files usable:
http://www.izotope.com/products/audio/rx/

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Answer 8

Jun 13, 2009 12:53 AM in response to Sampleconstruct

Thanks for the tip, I'll give it a try.

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Answer 9

Caramby

Level 4

1,523 points

Jun 13, 2009 3:31 AM in response to Phil Huddlestone

Wait… let's clear up a potential ambiguity here. Are you saying that when you opened up the GarageBand files in Logic's Audio Bin, they are still distorted (although you have been able to clean them up a bit)?

Perhaps although they 'sound good' in GarageBand, this may just be that the monitoring conditions are different — IOW, that Logic reveals them in all their distorted glory, whereas in GarageBand the same files are veiled.

In that case, your problem would be with the original GarageBand files, & not with Logic.

We'll know for sure once you've examined the originals in your new utility.

But if this is the case, then the 'fix' has got to be one of two things:

• 1: re-record the files (best solution if possible)
• 2: try to use Logic's noise-correction filters to clean up the files as well as you can.

There are quite a few tools in Logic for this sort of thing, but I'll wait for your results before I go into all that…

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Answer 10

Jun 14, 2009 11:24 PM in response to Caramby

Over the weekend I re-recorded the affected tracks using Garageband, using the same levels, parameters, etc. I imported the song into Logic, exported it again as audio files and there was not even a hint of distortion, so I'm guessing the original files had somehow got corrupted. I also recorded the tracks again, this time using Logic, and exported them with same distortion free result.

I'm new to Logic so I really appreciate you taking time out to help. Many thanks. Oh, by the way, any tips you can give on Logic's noise-correction tools would be greatly appreciated.

Once again, many thanks.

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Answer 11

Caramby

Level 4

1,523 points

Jun 15, 2009 3:25 AM in response to Phil Huddlestone

Glad the problem went away!

Why not post a new question about noise-correction?

🙂

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