Regular Columnists

What Is A Broadcast Quality Recording?
Part 8: Monitors and Routing


Monitors
Who is listening and how are they listening? Is it an exec on his way to work listening to mp3’s on a portable mp3 player? What is the quality of that mp3? What is the quality of the recording before converted to mp3? Is there a qualitative difference between listening to a CD in a car or office vs. listening to an mp3 streamed on the Internet heard on a laptop sitting on a beach in Bermuda?

What you hear in a studio is not what you hear in the wild. Recordings are mixed and mastered in pristine environments using the highest quality playback monitors possible. Of course, home studio environments approximate this accuracy. Meanwhile, the final result is heard back by consumers using a plethora of playback devices from CD players to consumer-based computer speakers, from restaurant sound systems to 20-year-old car radios.

Studio Monitoring speakers are almost always arranged both “near field” and “mains.” Basically, you’re listening to the mix from close and from far, or in a small space versus a larger space. Different speakers bring out different frequencies, like a magnifying glass. The kind of music being recorded will have bearing on the kinds of speakers needed. Dance music favors a bass drum while hard rock favors guitars. But most studios and mixers work across a range of genres, so having a set of speakers for each genre is a bit much.

Many mixers like to test run their mixes across a range of playback devices. What is heard in a pristine studio environment is not what is heard on a cheap boombox. But, mixing for the lowest common denominator might not be the best strategy. The quality of playback—from home theaters to car stereos to headphones has significantly increased over the years. Fewer and fewer people are listening to music through poorly designed or cheap speakers, like the old days of an AM car radio.

Like any other piece of equipment used in recording studios, there are dozens of monitor manufacturers offering a dizzying array of choices. Some speakers favor different frequencies, from high to low. Others give a better sense of balance. In the case of monitors that are weak on the low-end, subwoofers are needed.

What happens in a mix is entirely dependent on what is heard through the monitors. Playing pre-recorded commercially released CDs through studio monitors is one way to test speaker quality.

If the speakers are not powered, a good amplification system is equally critical.

Headphones are great for monitoring as well. Considerations in using headphones include low bass response, stereo imaging (different than monitors), and what your ears hear through headphones is very different than what you hear through loudspeakers.

Izotope—a company which makes the Ozone mastering software suite and other software products—recommends the following site for learning more about headphones: Headroom

Consumer manipulation (volume control, EQ, bass boosters, etc.)
Some mixers advise checking a mix on as many playback systems as possible. This rule seems to be a bit misguided. Top producers and engineers are ensuring the best possible mix regardless of what system is used for playback by the consumer. It’s unlikely that top producers and engineers are sitting in their studios with tinny car radios or beat-up cassette players to see how their sound works for the lowest common denominator. Also, these top producers and engineers are mastering for a variety of formats played back across sound systems far superior to cheap car speakers and home stereos. The highest quality recording will insure the highest quality of playback regardless of devices.

Boom Boxes
There’s an irony in "boom" boxes. A “boomy” bass in a mix is generally not a good thing. What were "ghetto blasters" designed to do? Well, they weren't designed to achieve the highest quality of sound. They were designed to play at a volume loud enough to claim territory and defeat the enemy.

Routing
Setting up “sends” and “returns” is a matter of routing, determining which submix goes through which effect. One submix might not need the master reverb added, so it’s routed differently. There is some debate over using mono and stereo sends. It’s a matter of choice and depends on the quality of the reverb.

Routing the sends through different effects like delay or flanger is a delicate art. The effect is heard when the track is solo’ed, but becomes a part of the blend when heard in the full mix. Yet, it did the job of creating space. Which tracks or submixes get sent to which effects is a matter of experimentation, with the goal of creating a space for each instrument, the vocals, the rhythm, the backup vocals, etc.

All the “returns” are returned to the master stereo output. Being able to dedicate a mixing console channel for returns offers greater flexibility and control, especially with EQ’ing. Some effects get lost when mixed with others or when a master effect like reverb is applied. Plus, there is the advantage of controlling the effect through the console rather than the effect unit itself. Next is finding a wet/dry balance as well as panning locations.

Setting up routing schemes can get pretty complex. Instruments are plugged into the main console. From there, they can be routed in myriad ways, through submixes, F/X units, compressors and a number of other auxiliary returns and sends.

Eventually it all comes together in a master stereo out. The final result is then further mastered in a mastering house.

Spatial considerations are important. Each instrument occupies it's own “space” within the stereo or surround field. This is accomplished through effects, usually reverb. Panning alone is not sufficient to establish space. Effects must be used judiciously to avoid a “wash out” or mudiness.

Some mixers like to use a slew of reverbs rather than just one to allow for a variety of perspectives. Following this is the master reverb. There is also debate over mono versus stereo signals used for both sends and returns.

Effects heard on solo'ed tracks are often lost in the full mix. Even though they can't be heard, they are still “sensed” in terms of the overall spatial effect. Another way to describe space is putting an “air” around instruments. Some engineers use a variety of techniques to achieve this spatial quality. They use different effects depending on whether its separating guitars from keyboards, or background vocals from the main vocals.

It's a delicate balance between the effects used on individual tracks and the master effects used in the master stereo out. Effects units offer their own wet/dry balances, which can be further routed and balanced through the console. Equalization is used to further shape how effects are used, as well as panning both effects and tracks (channels).

The order in which tracks are mixed varies from engineer to engineer. Some start with percussion, others start with vocals.