Four Essential Tips for Mixing with Headphones
With the ever-increasing mobility of music production equipment, the subject of mixing and mastering on headphones becomes increasingly relevant. While there is no real substitute for mixing and mastering on tuned near- or mid-field monitors in an acoustically treated room, headphones certainly have a role to play in production. Whether for convenience, portability, noise considerations, or other reasons, here are a few ideas to keep in mind when mixing with headphones.
1. Protect your Ears
When wearing headphones, recognize that because the drivers are situated directly next to your ears, there can be a greater risk of hearing damage than there would be when using studio monitors. Because wearing headphones can be rather immersive, and mixing is often a very time-consuming process, it's essential to take regular breaks to prevent hearing fatigue. Keep track of both the SPL level and the amount of time spent mixing, so you don’t accidentally damage your hearing. The following is a chart of permissible sound-exposure times at different SPL levels from the CDC:
|85 dB||8 hours|
|88 dB||4 hours|
|91 dB||2 hours|
|94 dB||1 hours|
|97 dB||30 minutes|
|100 dB||15 minutes|
|103 dB||7.5 minutes|
|106 dB3||.75 minutes|
|109 dB1||.875 minutes|
|112 dB||Less than 1 minute|
|115 dB||Less than 30 seconds|
2. Choose Your Gear Wisely
A wide variety of headphones is available for various applications. When mixing, it's important to select a pair that has as flat of a frequency response as possible, so your mixes will translate across different playback systems. Many headphones are designed for personal or hi-fi listening, and provide a deliberate bump in the bass, and a cut in the treble, to make the music sound more fun and engaging. While this is great for listening, it can lead to problems when mixing, because the frequency response of the headphones can skew your perception of the frequency response of your mix.
Another major consideration is whether to get closed, semi-open, or open-backed headphones. Open and semi-open-backed headphones usually have a flatter frequency response, and a more realistic presentation of bass. However, open headphones are unsuitable for tracking and recording applications, because an audible sonic bleed can get picked up by your microphone(s).
One option to consider is purchasing headphones and studio monitors that are made by the same manufacturer. The engineering departments of many audio companies will design and voice their headphones and monitors to complement one another. For example, if you're in the market for both headphones and studio monitors, consider buying a pair of Focal Spirit Professional Headphones and a pair of Focal Alpha monitors. These products were designed to be compatible with one another, so that you can switch between headphone and monitor mixing, while retaining a relatively consistent sound signature.
Ultimately, the question of what to buy is subjective, and the only way to know what works for you is to audition a variety of headphones. Select the pair (or pairs) that work best for the style of music you intend to mix.
Here are a few headphone recommendations:
- AKG Q701
- Audio Technica M50
- Audio Technica ATH-AD900X
- Beyerdynamic DT 770 Pro Studio Headphones
- Beyerdynamic DT880
- Focal Spirit Professional Headphones
- Sennheiser HD 650 Headphones
- Ultrasone Pro 750 Closed-Back Professional Headphones
- Sony MDR-7506 Circumaural Closed-Back Professional Monitor Headphones
If you have the budget for it and really want to invest in headphone mixing, consider purchasing a dedicated monitor controller, such as the Dangerous Source. One step further is to invest in software or hardware signal processing that helps model the way sound moves within a room, for an experience that more closely resembles the experience of mixing with real monitors.
On the software side, take a look at IRCAM TOOLS v3 Binaural Encoding Plug-in Tool for Headphones. This software models stereo or surround mixing using a virtual matrix of selectable speaker configurations. It was developed by the Institut de Recherche et Coordination Acoustique/Musique in Paris, using a dummy head and torso simulation that provides an approximation of how human beings perceive sound. It's available in AAX Native, Audio Units, or VST formats on your DAW of choice. Also check out IRCAM’s extensive line of reverb and acoustical room modeling plug-ins. Their signal processing is state of the art.
On the hardware side, Beyerdynamic offers the Headzone Pro Surround Sound Headphone Monitoring Systems. This processor models virtual control rooms with adjustable distances from virtual speakers, speaker angle, room size, room geometry, reflection patterns, and ambience characteristics, among others. It includes software for optimizing headphone SPL, and managing healthy noise exposure. It also features the option of including an HR 2 ultrasonic head movement/position tracking system, that utilizes a sensor mounted on a Beyerdynamic DT 770 Pro HT or DT 880 HT Pro headphones to communicate with the hardware unit. The system will adjust to model the way sound arrives at your ears in real time, based on their position in relation to the ultrasonic receiver.
3. Learn your gear on mixes you know
Realize that when mixing with headphones, you're not trying to make the track sound good just on that particular pair of headphones, but rather, you're creating a mix that will translate well to a variety of different playback systems. This can be difficult because the physics of headphones make it nearly impossible to generate the full-frequency spectrum. Bass sounds require significant space for the waveforms to develop, and headphones lack the majority of spatial information needed for stereo imaging and reverb processing.
To make a mix sound the way you would like it to on other systems, it's useful to maintain a catalog of reference tracks that you know well. For example, imagine you're working on a "bass drop" in an electronic music song, and you want it to hit in a way similar to the drop in a track that you really like. Listen to the reference track through your headphones, and work the low end on your own mix so that it sounds similar to the reference track. Then check to ensure that both your mix and the reference mix sound the same on a pair of near- or midfield studio monitors.
4.Manage your expectations: know what to mix on headphones, and what to leave for studio monitors
"Headphones can be very useful for focusing on subtle details and correcting errors in individual tracks."
Headphones can be very useful for focusing on subtle details and correcting errors in individual tracks. The clarity and isolation from acoustic coloration can make it easier to fix problems with distortion, pops, and clicks, as well as perform dynamic signal processing, such as compression on individual tracks.
On the other hand, headphones are not so good for tone-shaping processes, such as equalization and reverb, because the frequency response of a sound (especially bass frequencies) varies with the distance from the source and the acoustic properties of the space in which the sound occurs.
Unless you decide to invest in acoustic signal-processing hardware or software, such as the products mentioned earlier in this article, it's probably best to limit headphone mixing to the error correction of individual tracks, and leave other processes such as imaging, tone shaping, reverb processing, and low-frequency mixing for a time when you can use studio monitors.