Years ago I saw someone use a program for Windows and I was hoping that someone can tell me if there is a Mac equivalent!

Say you are watching a YouTube video and the audio is up full but it's still quiet. The audio on the video is out of sync too.

You open this program and you can increase the audio even though it's full on YouTube. You can also speed up the audio so that it is in sync with the video.

Is there an app available for OS X that allows me to do this?

  • Google "youtube sound amplifier" – markhunte Jan 10 '15 at 16:19

Personally, when I came across a YouTube video with low audio output, I use an app called VLC player and its audio to boost the signal.

The VLC player is free.

Just copy the YouTube video link in the VLC player, then use its Audio to modify it to your liking.

It also comes with a very handy Audio Mixer, allowing you to set up full range of audio output.


VLC also allows you to synchronize the Audio-Video playback and more.

For example, while you're watching the video, just press the J or K keys to move the audio back or forward 50 milliseconds (or more), respectively.

  • Perfect! Exactly what I was looking for. I was aware of this program but I hadn't realised it was capable of doing this. Cheers! – Kevvvvyp Jan 10 '15 at 17:26
  • that's brilliant. – David 天宇 Wong May 14 '18 at 12:42

A costly solution: the Boom app: http://www.globaldelight.com/boom/

It boosts the system volume

  • Looks really cool! I think this would be my ideal solution although I'm not sure I can justify paying for it. Good find! – Kevvvvyp Jan 11 '15 at 12:59

You can use Audio Hijack Pro:

  • $32
  • Amplify a specific application or the entire system audio:

enter image description here

  1. Launch Audio Hijack Pro.
  2. Open the main window by choosing Window > Audio Hijack Pro.
  3. In the left-hand column, select the program you wish to amplify.
  4. Click one of the "Click here to insert effect" squares.
  5. Choose FourFX Effect > Gain. A gain control appears.
  6. Click the Hijack button to enable the new effect.
  7. Adjust the right-hand Gain controller to boost the hijacked program's volume in real time.
  • tons of other features

enter image description here


Free solution: https://bongiovidps.com

Allows you to boost system volumes and also adjust how it sounds. It installs a menu bar item.

  • only appears free during 30 day trial. – Robert Lugg Jul 23 '19 at 6:29

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