Here’s an interesting tip for those who have third party MP3 players or perhaps old audio equipment such as a cassette player. It lets you play audio through your Mac’s speakers from any device that has a headphone jack or line out.
You’ll need an audio cable terminated at each end by 3.5mm jacks. These are dirt cheap nearly everywhere. Alternatively, if you’re outputting from hi-fi equipment, you’ll need a RCA/phono-to-3.5mm lead, which again are plentiful and inexpensive.
Once you have the lead, connect one end to your MP3 player/cassette player/hi-fi equipment, and the other end to your Mac’s line-in. Don’t think your Mac has a line-in? The chances are that it does because the headphone jack doubles as line in, as I explain in a moment.
Here are the steps:
1. If your Mac lacks a dedicated audio in, hold down Option (Alt) and click the volume control at the top right of the desktop. A menu will appear. Select Use Audio Port for Input.
2. Start playing audio on the MP3 player, cassette deck, or hi-fi equipment.
3. Open QuickTime Player and from the file menu, select New Audio Recording.
4. Click and drag the input volume slider on the QuickTime transport controls until you hear something. You might have to adjust the output level on the MP3 player or hi-fi equipment, if that’s possible. If you still don’t hear anything, click the small down arrow at the right of the QuickTime transport controls and ensure Built-In Input: Line In is selected under the Microphone heading (yes, I know this doesn’t make sense).
Then minimize QuickTime Player, and listen to your music! When done, as well as closing QuickTime Player, don’t forget to Option-click the volume control again to switch the audio port back to being an output rather than input.
Of course, you can also click the record button on QuickTime Player if you want to make a recording of the audio.
(Before anybody suggests it: There’s a free app available that negates the need for QuickTime Player in order to listen to audio: LineIn by Rogue Amoeba. However, the focus of this blog (and my book Mac Kung Fu) is to use OS X’s built-in tools wherever possible.)