Setting Up Your Mix Room
Although it is sometimes useful to view the world through rose-colored glasses, we can’t mix that way. We need to see—well, we actually need to hear—our mixes exactly as they are, uncolored by a flattering monitoring environment. We don’t want rose-colored loudspeakers and rooms, unless they go nicely with our shoes. We definitely don’t want rose-sounding mix rooms.
We can’t hear what our mix really sounds like unless we work in a room that is predictably accurate, honest, and revealing. We need to hear the recording we are creating, independent of the equipment and room acoustics of the mix space. We can’t create a great-sounding mix until we create a work environment capable of sounding great.
If you’ve seen carefully designed recording studios, you know that the architecture and construction techniques get pretty complicated and pretty funky. Books have been written and teams of specialists stand by ready to help anyone properly address the many details associated with building a mix room. Acoustics is a deep but fun field. It is also a sometimes counterintuitive branch of physics and a discipline rich with poorly informed people peddling products and myths that don’t help the room. Study room acoustics. Hire qualified specialists. Your mixes will sound better when your room sounds better. If you want to get good at mixing, get a good room built. Such a task is vast and can best be done as a collaboration among the requisite experts. Key things to keep an eye on include:
- Locate your studio as far away from noisy machines as possible (air conditioners, heaters, refrigerators, helicopters, fire stations, shooting ranges, trombone factories, etc.). Choose the location for your room that best situates yourself versus all things noisy. Specialists can install the machines on necessary isolators to minimize the propagation of their earth-shaking vibrations, but it’s cheaper to start with a vibration-free space.
- You need a quiet space to work so that you hear even the quietest, most subtle details within the mix. Build appropriately designed sound-isolating walls, floors, ceilings, windows, and doors to keep unwanted noises out of your room, and—conveniently—to keep your sometimes-loud music out of neighboring spaces. Specialists can install proper heating, venting, and air conditioning equipment that provide comfort without distracting noise. Computer fans sonically drape a blanket of obscurity over your entire mix, unless you locate them in a well-isolated and well-ventilated closet or other space.
- We like to have as much left-to-right symmetry as possible, as viewed from the mix position. You sit on the center line of the room. When you compare the left side of the room to the right side—the loudspeakers, the walls, the windows—you want to see (and hear) a left side that is a mirror image of the right side—or as close to that mirror image as reasonably achievable.
- We typically design control rooms so that we hear the sound from the speakers without corruption from the room. One common defense is to prevent the first (and second) reflections of the sound radiating from the loudspeakers toward the walls, floor, ceiling, and furniture from bouncing toward the mix position. Carefully designed angles and bumps redirect the sound elsewhere. Strategically placed absorption attenuates the reflections as well. Consultants, architects, and good contractors can come up with clever solutions in this area.
- Reverberation is typically very short (less than 1⁄3 of a second or so, depending on the size of your room) so that we hear the reverb in the recording, not the reverb in the mix room. Specialists can help you hit the right target across all frequencies of interest. Beware of fuzz- and fabric-only solutions, as they may absorb high frequencies without taming the low frequencies appropriately, leading to the common problem of a short middle- to high-frequency reverb time, undermined by a boomy, lingering low-frequency reverb time.
- Rooms resonate at some frequencies better than others, and in the smallish rooms typical for a mix room, those resonances are well within the audible frequency range. Acousticians can calculate, estimate, and measure these room modes and design ways to minimize their effect on what you hear in the room.
- Loudspeakers present a great challenge, as they must be consistent in behavior from the lowest to the highest frequencies. A flat frequency response indicates that the output amplitude from the speaker is fairly consistent, neither overly emphasizing nor attenuating certain spectral regions.
- The frequency response isn’t the whole story, however, as it says nothing about time. Transient detail and image accuracy come only from loudspeakers that do not blur things in time. It is not enough that the loudspeaker have good output down to 40 Hz. We also require that 40 Hz energy to be created with the same agility as the middle and high frequencies.
- The laws of physics can never be broken, no matter how rebellious you otherwise are. Beware of speakers that look too small to sound so good. The large wavelengths of low frequencies need large drivers, significant power, and/or extra design emphasis to have not only amplitude output, but also time integrity.
- The placement of the loudspeakers within your room is a decision that has a profound effect on sound quality. Should they be against the front wall, or away from it? How far from the side walls is best? There is no single correct answer. These important decisions are made with the help of specialists and are tailored to your specific room size, geometry, treatment, and the type of loudspeakers you’ve acquired. It’s never simple.
- There’s still more: power response, directivity, power handling, efficiency, and the like. As with room acoustics, don’t hesitate to read up on loudspeakers and talk to experts.
What about headphones?
- Headphone listening is quite different, physically and physiologically, from loudspeaker listening. And although current trends point towards increased use of ear buds as a mode of listening to music, the vast majority of listeners will hear your mix over loudspeakers. It is very unwise to mix in headphones hoping to predict your mix’s efficacy through the completely different user interface that loudspeakers offer. It is fine to occasionally listen to your mix on headphones to hear how your mix decisions affect the headphone listener’s experience. So mix through loudspeakers, and occasionally put on some headphones to hear this other listening modality.
- Use headphones as a way to check for hard-to-hear details that might be missed when listening to loudspeakers. Distortion, channel-specific problems, brief errors, instantaneous clicks, brief pops, short-lived dropouts, and other details are quite effectively revealed in headphones. For quality control, headphones are a great way to zoom in, magnify, and scan for problems. But allow your overall mix aesthetic to be developed on loudspeakers.
Working in an inferior room with mediocre loudspeakers holds back the quality of your mixes, the pace of your learning, and the success of your business. Room design and loudspeaker selection are critical first steps, worth a thoughtful investment of time and resources and likely relying on specialists to get right. Don’t skip this step.
Excerpt from Mix Smart: Pro Audio Tips for your Multitrack Mix by Alex Case © 2011 Taylor & Francis Group. All Rights Reserved.