MIX TECHNIQUES - PART 1

Dynamics Processing

By Brian Stephens

There are three main families of effects that are traditionally used during mixing: frequency-based, time-based, and dynamics-based effects processing. This month, our focus is on the most misused of these effects - dynamics-based processing. We really don’t have time for the complete “Dynamics Processing 101” in this article but, I would recommend that you check out Modern Recording Techniques by Huber & Runstein and Practical Recording Techniques by Bruce Bartlett as great resources for the basics. Instead, I would like to give you some tips that you will not find in those text books.

Most people think of compressors as simply a method of decreasing the dynamic range for an instrument or voice, allowing you to place it in a mix more exactly. What many people do not realize is not all compressors yield the same results. On one hand, some compressors will do their job while leaving the sound quality of the original track virtually intact. Hardware compressors like the Behringer Composer Pro (pic. 1) and many basic software plug-in compressors like the one found in Nuendo (pic. 2) do the job of compressing the dynamic range of a track without changing its overall tone color. These types of compressors are great when you like the sound of the original track and only wish to change the apparent loudness of that sound within your mix.

On the other hand, there are other compressors that will change the tone color of the track on which they are used. The real trick to note here is that different compressors are going to provide wildly different results so you must really listen and choose wisely. The Universal Audio 1176LN compressor (pic. 3) has a tendency to brighten up the tracks on which it is used. I will use this compressor on acoustic guitars and certain types of keyboard patches (i.e. strings, brass, etc.) when I need to get a little more sparkle out of them or to counteract the dull masking effect that other nearby tracks may cause. Another classic compressor, the Univeral Audio/Telectronics LA-2A (pic. 4), has the ability to add a great deal of warmth to any track. I tend to use this compressor on tracks like bass guitar, B3 organ, and heavier, rock rhythm guitar. This warmth can help to fatten up the tone of the track, without the use of EQ, and give each track a lot more girth inside your mix.

The bad news is that hardware models like the 1176LN and LA-2A are expensive pieces of equipment to own. The good news is that they have found another life, and are considerably less expensive, as DAW plug-ins. For about one-fifth the cost of either unit, you can own an entire virtual rack of them using a product like the Universal Audio UAD-1 card. Having used both the hardware and software versions of these compressors extensively, I can easily say that these plug-in versions are so close to the sound of the original hardware that no one will know the difference.

For another variety of warmth, I look to any of the Joe Meek family of compressors. My personal weapon of choice, the MC-2 (pic. 5), adds a rich warmth to my original track reminiscent of older British audio equipment. It also adds a certain texture to any track that instantly sets it apart from other tracks in the mix. Lead guitar, Moog-style synths, and saxophone seem to work well with this compressor.

One last hardware piece that can give you the best of both worlds is the Behringer Tube Composer (pic. 6). This compressor has a dial that allows the user to tune in the exact amount of tube circuit used. The misnomer with this unit is that the tube circuit does not provide added warmth but rather acts like an aural exciter, adding sparkle and high-end sheen to the track. I often use this unit to brighten up snare drums, banjo, and any percussion tracks I might have in my mix. Without the tube circuit dialed in, the Tube Composer acts just like its cousin, the Composer Pro, providing transparent compression for any type of track.

With all this talk about specific pieces of equipment, you are probably wondering if there are any special tricks for using these compressors in your mix. Generally, I use any of these compressors moderately with ratios set anywhere from 2:1 to 4:1. (NO real secret there.) One trick I use inside most in every mix is to stack a couple of compressors to get two jobs done at once. Let’s say I have a bass guitar track that alternates between long, fat, low notes in my verses and punchy, slap/pop-style playing in the choruses. First, take a transparent compressor like the Composer Pro or generic plug-in compressor and set it up for a higher ratio (usually around 4:1), a quick attack (10-15 milliseconds), and, finally, set the threshold to catch only the attack of each note, especially the chorus parts slapping. Next, pull in an LA-2A to fatten up the overall sound. Set the “peak reduction” knob so that you get 2-4 dB of average gain reduction and then use the gain knob to make up for any volume that you have lost during this double compression process.

A common problem that many people face is mixing a drummer whose volume and attack vary wildly across the length of the song. Instead of heavily compressing the overall drum mix, I will set higher ratios for all the close mic’ed drums, usually between 4:1 and 6:1, and additionally will use a limiter whose threshold is set to limit almost every single kick and snare hit. If this does not keep the drums set evenly in the mix, I will then look to combine all the drums into one stereo bus and compress that output bus. This method gives me more control over the balance and tone of the individual drums while controlling the dynamics of the performance.

Aside from a handful of insider tricks, choosing the right compressor for the job is as important as actually using one. The coloration that a dynamics processor induces on a track can be used to your advantage in many cases. By using the right piece of equipment for a specified reason, you can be assured of getting the desired effect inside of your mixes. In the end, your use of dynamics-based processing should help to make each individual track sit more precisely inside your final mix.