Welcome back to part 3 folks! The part we start to explore the wonderful world of compression. I’d like to preface this topic with there are soooo many aspects of compression that during this discussion I’d like to keep to key topics that will help us better control dynamic range in the cool non-distorted kinda way. In other words not a Britney Spears record. I prefer to be A-D to D-A converters best friend. I hope to do a compression series later on and really break down several subtopics of compression, but until then lets shed some light on using it more wisely in our louder mixing endeavors.
As we should all know as a mixer a compressor helps us control our dynamic range, but do you know how compressors do what they do to control it? The two most common kinds of compression we use are RMS and peak sensing sidechain circuits. RMS circuits control the dynamics from the overall average level of the signal (the most musical, logical, and widely used compressor), and peak circuits are designed to control those momentary, out of control transients and annoying sounds (think limiters and de-essers). How can we effectively use these tools to control our dynamics in a pleasing way? I’m glad you asked!
RMS are our friends when we want gentler, smoother compression to help level out our tracks. The biggest key to not sucking the life out of a mix with this though are proper attack and release times. Lets think of the attack as our lifeline to keeping punch and energy to our tracks and overall mix(breathing in), and the release as a tone shaper as well as breathing rhythm (the exhale!). So, how quickly is that track breathing in and exhaling out? I find this to be a pretty useful analogy. The slower you let the compressor breathe in on the attack the more punch you can get from the transient. If you leave it too long it can end up eating headroom, though. The faster the compressor breathes in (to keep with the analogy) the faster it sucks the life right out of the transient while still controlling the peak transient. The attack time can be a crucial element when finding that good dynamic point of control while retaining the life of the track and music. The release can help shape the tone of something. Lets use a kick drum for example. We’ve found this punchy rocking attack on our kick, but there’s just way too much of that resonant WAHHHH ring let afterwards? This is where we can use the release to our benefit. If you have it set fast it’s going to let go of that compression quickly, and that ring is still going to drive us nuts. As we start to slow the release down magic starts happening! The ring starts to disappear as it’s ducked in the compression still leaving those annoying resonant frequencies behind with even more headroom. If we just use critical listening on these key elements we can really help tighten our mixes and masters while controlling headroom issues. I’d also like to warn you about too fast of an attack and release can create audible distortion sometimes keep a critical ear open.
I’ll wrap up the first part of compression in this series with using series compressors. A great way to use compression especially on vocals is to stack 2 or more in series using only a couple dB of gain reduction on each. The compressors won’t work as hard as one would with 6-8 dB or sometimes even more of reduction thus making it sound gentler in return. Another use of series compressors is to use one RMS sensing compressor first to help even out the dynamics then a peak sensing limiter afterwrds to help tame 3 or so dB of peaks to help from choking any peaks. Using the RMS compressor first makes the job easier on the peak limiter as it doesn’t have to shoot as far to reach the peak allowing it to control peaks easier. Never be afraid to add some EQ or some sort of harmonic exciting after if the compression ended up dulling the sound a bit too much for your liking. The biggest key to this is just use a little bit. It goes a long way! A key to a great mix is all about the lots of little things. Less can create so much more when mixing. I hope you all got something from this! Did this help in any way? I’d love to hear from you in a comment below! Thanks Mixcoachers! I’ll be back with part 4 next week.