Q: I am hosting a house party in the near future and I would like to play music from my iTunes library through my Pioneer DJ mixer. The mixer will be connected to an amp so the music will consequently be played through speakers. How do I do this through my MacBook Pro?
A: There are several ways to accomplish this. If you’re going to have your MacBook Pro near your audio system, the simplest solution is just to connect a cable from the line-out/headphone port on your MacBook Pro directly to the line-in on your mixer.
Any standard cable with a stereo 3.5mm headphone jack should work fine for this, with leads on the other end appropriate to the inputs on your mixer—usually RCA-type connectors. These cables are quite common and you should be able to find one at your local stereo or electronics store.
If your mixer has optical inputs you can also use an optical connection from the MacBook Pro line out port, which will theoretically provide better sound quality depending on your source material. The MacBook Pro actually supports both analog and optical output via the same port, although you’ll need a cable with an optical mini connection, or an adapter for an existing Toslink optical cable.
Adapters can be found at most higher-end electronics and stereo stores.
Alternatively if you want to keep your MacBook Pro in a different room or roam around with it then you may want to consider picking up an Apple Airport Express ($99), which allows you to stream music from iTunes to a set of connected speakers over Wi-Fi and provides similar audio output capabilities—both analog and optical.
The Airport Express can be configured to join your existing Wi-FI network or hooked up via an Ethernet cable and can be conveniently plugged in behind your stereo system and connected to your mixer. You can then simply select it as an output source from the AirPlay menu which appears in the bottom-right corner of your iTunes window.