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I have a Unibody Macbook running 10.5.5. When I play videos in QuickTime the audio is low even after I raise both the QuickTime volume meter and the system volume meter to the maximum. When I play the same videos in VLC, the VLC volume meter allows me to raise it to a louder level.

Why is this?

Is there a tool for the Mac that allows me to amplify my sound outside of VLC?

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2 Answers 2

VLC's sound level goes up to 400%. Quicktime maxes out at 100%. I'm not sure why that is, but that's one of the reasons I use VLC instead of Quicktime.

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it's because VLC beyond 100% artificially amplifies the wavform. no problem if the wavform is quiet, but if loud you'll get distortion. –  quack quixote Oct 8 '09 at 20:48
Is there an app that can artificially amplify sound for the general system volume? –  hekevintran Oct 8 '09 at 21:24
i have one called "external volume knob on my powered speakers"... –  quack quixote Oct 8 '09 at 22:26
Note that you could probably damage your macbook speakers by putting the volume above %100 using VLC, depending on the source. VLC lets you do it in case the original waveform is super quiet, but unless there is a hardware or software to limit the speaker volume, beware. –  MGOwen Oct 19 '10 at 3:29

You should be able to boost the volume by holding down shift while adjusting the volume. See this lifeclever tip, which seems to be regarding a rather old version of QT. Not sure if this still applies to QuickTime X -- can anyone verify that?

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That's a neat trick. I'm running 10.5 so I don't know if it works on QuickTime X. The QuickTime on 10.5 doesn't have the volume meter shown in the screenshot, so you can't do the shift trick. QTAmateur (mikeash.com/?page=software/qtamateur/index.html) does though and it works there great. –  hekevintran Dec 26 '09 at 17:44

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