How to Do a Quicktime Screen Capture With Audio

First you have to install soundflower plugin
After the Install go to >Apple System Preferences

Click On Sound

Choose Output

Soundflower 2Ch.

Open QuickTime Player

Click on >File>New Screen Recording

click on the down arrow icon next to the recording icon and choose

Soundflower (2Ch)

Find the web content you want to record youtube or vimeo or etc

Pause the video where you want to start recording

Click on the RED record button on Quicktime Player

Drag the box around the web video window you want to capture and then

Click on the Start Recording Icon

click in the top tool bar on the mac window and click on the "Stop" icon

You will have the freshly recorded quicktime but to hear it on the mac you

have to change the sound output back.

Then go to >Apple System Preferences

Change the output back to Internal Speakers or Headphones

You should be able to hear the audio off the quicktime now.

Finally you will be able to save the video to use as a quicktime.