Studio Monitoring Basics

Ever worked for hours and hours on a mix and then taken it to your car, or to a friend’s house where you played the same mix and discovered it sounded nothing like it sounded in your studio? Then you already know exactly why accurate monitoring is needed.

In this article, I’m going to provide a general overview of three factors that contribute to the sound you hear in your studio. After I do that, I’ll give you some tips for improving the setup in your own studio. By the time you’re done reading, you’ll have a good grasp on some of the common problems associated with studio monitoring and how to get around them.

What are you really listening to?

The way I see it, your reference mix is the result of three components, each with it’s own set of variables and each interacting with the other two components to ultimately create the mix we hear in the studio.

  1. The reference monitors / speakers
  2. The Room Acoustics
  3. The human auditory system (ie: your ears and your brain)

I’ve attempted to illustrate this dynamic relationship in the following diagram.

What we hear is determined by several factors in our studio.

1. The Reference Monitors

The first stage to consider is the monitors that you are using.

Every set of monitors has a certain way of responding to and reproducing the various frequencies that are put through them. Some frequencies will be emphasized and others will be de-emphasized according to whatever nonlinearities there are in the monitors frequency response.

Although there may be certain frequency ranges that are not noticeably affected, the overall result will be that your mix will have essentially been changed.

Graphics A and B represent this idea. Graphic A represents the frequency balance of your source audio as a perfectly straight line (linear).

Flat Frequency Response

Flat Frequency Response

Next, Graphic B illustrates the uneven (non-linear) frequency response of the monitors / speakers. Your mix sounds different through the monitors because they are reproducing some frequencies louder or softer than they really are (at the input). Which frequencies are boosted and lowered? By how much? And at what playback volume? That depends on which set of monitors you’re using.

Graphic B: Altered frequency balance

Non-linear frequency response

2. The Room Acoustics

Your listening space has a profound affect on the sound you hear. It takes the mix coming out of your studio speakers and alters it by reflecting sound off of surfaces or by absorbing sound into various objects within the room.

At the same time, sound waves intersecting with each other in the room cause certain frequencies to pile up while others seem to disappear. What you’re left with are large peaks and dips in the frequency response.

Further coloration caused by room acoustics

Coloration caused by room acoustics

Mixing in a Concrete Stairwell

To further illustrate the point, think of the way your voice sounds in a concrete stairwell. That full low end and long reverb tail are the sound of the space, not your voice – right?

Now, imagine setting your speakers up in that same concrete stairwell and trying to mix a song. Obviously, it would be extremely hard to separate the direct sound of the mix coming out of the monitors from the sound of the countless acoustic reflections echoing, piling up, phasing each other out and creating a sonic mess.

Now, consider what your room might be doing to your sound. Is there a sofa, drapes, or a closet full of clothes absorbing sound? Perhaps there’s a wall just behind your monitors, or a window beside you, or a glass picture frame or a flat newly painted ceiling creating reflections? Chances are pretty good that you’re in a rectangular room with parallel surfaces (walls, ceiling, floor).

All of these acoustic absorbers or reflectors introduce gross peaks and dips in your frequency balance. It may not be as extreme as a concrete stairwell. But the bottom line is the same: your room is hindering your ability to hear an accurate picture of your mix.

3. Your hearing

The third stage of monitoring that requires consideration is your hearing. The human auditory system is unbelievably brilliant and complex.

One of the characteristics of your hearing is that your frequency response changes depending on the listening levels. People’s hearing is most sensitive to sounds in the midrange. At lower volume levels, we are less sensitive to sounds away from the midrange. Bass and treble sounds seem reduced in intensity at lower listening levels.

So, when you monitor your music loudly at 105dB and come up with a nice balance where everything seems to sit just right in the mix, you need to keep in mind that THAT (105dB) is the only volume at which you will get that exact mix.

When you play that same mix at a low level (75dB) the perceived frequency balance will also change. Along with being quieter overall, it will also sound like you turned down the bass frequencies and the high end more than the mid-range.

Update: April 2009. Solutions

Thanks to visitor feedback, I realize that I dropped the ball and have not posted any articles with clear solutions to the problems that I wrote about in this article.

For now I’d like to give you my quick take on the solutions, followed by some links that I trust and recommend for you to dig deeper into the basics of studio monitoring.

Problem / Solution Summary

1. Dealing with the ROOM using Acoustic Treatment. Using Bass Traps and other acoustic treatments to reduce the affect of reflections and standing waves in your space.

2. Monitor Positioning / Monitoring Levels. Making sure you are in an optimal listening position to your monitor speakers and that your monitor speakers are in an optimal position in the room that you are in.

3. Understanding your own hearing. This will improve the quality of your mixes without doing anything but being aware of what was happening to your perception of your mixes at different volumes.

Recommended Resources

1. For acoustic treatment know-how, someone that I really appreciate is Ethan Winer. He owns (or co-owns? don’t quote me on that part) a company called RealTraps. At the RealTraps site, he has several articles and some videos that are excellent.
This article in particular: http://www.realtraps.com/facts.htm

Also, Auralex, another acoustic treatment company deals with the subject quite well at their Acoustics101 site.
http://www.acoustics101.com/

They also have a Room Analysis service that you might be interested in. It’s free. (in the hopes you’ll buy the recommended products from them). http://www.auralex.com/pcf/

2. Sound on Sound Magazine has an article that deals with Monitor Positioning here: http://www.soundonsound.com/sos/mar02/articles/monitors.asp

3. Regarding the Equal Loudness Contours: Dave Moulton has some excellent material on the subject (and many other relevant subjects). http://www.moultonlabs.com/more/equal_loudness_contours/