HEADPHONE MIXES AND HEADPHONES
Sooner or later you’ll have to set up a headphone mix. A headphone mix is necessary when (a) you want to hear all of your Pro Tools tracks playing at once in your headphones, (b) you want to get separation between sound sources, and/or (c) you want to have separate mixes for some individuals. As an engineer you need to be aware of the recording and playback levels, the routing of audio signals, the hardware you’re routing it through, and how the overall mix sounds.

There are several ways to get multiple “feeds” to different sets of headphones:
• If you’re using your home stereo as the monitor output, plug a splitter into the headphone jack and run your headphones from there.
• If you have the 001 you can use the headphone output from the front of the I/O unit.
• If you’re using a mixer there are probably several stereo outputs that can feed headphones.
• If you’re using a home stereo and a mixer, you can utilize the headphone jacks from both units (as well as the one from the 001), giving you a total of at least four headphone outputs. However, using all of these different headphones with separate levels might get confusing.

A better solution might be to buy a headphone amplifier specifically made to supply multiple sets of “cans.” Simply plug any of the monitor outputs (home stereo headphone out, 001 headphone out, or mixer out) — or two direct outputs from the 001 (e.g., analog outputs 1–2) — to the input of a headphone amp. Each amp supplies multiple pairs of headphones with your stereo signal and every pair of has its own volume control, allowing each person to adjust their own overall level. Headphone amps may also accept multiple input signals, so technically you could supply some headphones with one mix and other pairs with a different mix. (Creating two or more headphone mixes is covered in chapter 11. This is a really cool feature — check it out.)

KEEP FEEDBACK IN CHECK

Besides Jimi Hendrix-like guitar feedback, we usually try to avoid feedback in studio environments. Acoustic feedback is created when two magnetic pickups (e.g., microphone and speaker) feed each other the same audio signal. An audio signal going into the mic comes out of the speaker back into the mic and so forth, creating a loop. This feedback loop is the result of the signal building upon itself and creating a sometimes painful and injurious noise. Feedback at high decibel levels can cause hearing loss — not to mention damage to equipment — so be careful! Therefore, it’s a good idea to keep your monitor level down or preferably off when recording using microphones in the same room. Create a headphone mix instead.

Buying Headphones
When buying headphones for your home studio it’s most important to consider how they’ll be used. Will you be using them during recording sessions? Consider buying closed-ear headphones so there’s minimal sound leakage while tracking. Will you be using them to mix? Consider buying headphones with a flat frequency response so you’re sure of their accuracy. Will clients be using these headphones for extended periods of time during sessions? Consider comfort as a main factor in the equation.

There are three general types of headphones: open-air, semi-open, and closed-ear (or sealed). These terms refer to how much sound isolation the headphones provide. Often the open-air or semi-open are more comfortable than closed-ear headphones because they don’t fit so tightly. However, open-air and semi-open headphones allow some amount of sound to escape into the room. That means the sound could leak into microphones in the recording studio — particularly important to consider if you’ll be recording with a click track. Sealed headphones allow very little leakage, so click tracks and other loud signals won’t be picked up by mics in the room.