Thursday, June 26, 2008

Compression Depression

Do you suffer from compression depression?
Here are the symptoms, as they were explained to me.
First of all the sufferer shows a blatant disregard for the understanding of the sliders, knobs, and titles of the many different parameters that make up most compression effect units. We, myself included, never looked into what any of the endless parameters found on compressors did. Words like ratio, release, attack only boggled my mind, and I found myself tweaking them endlessly. It is a common trait of the depressed, and compressed deficient, to play with the many knobs and sliders just to watch the multi-colored lights light up, until hopefully the music sounded "cool" to our ears.
I was a long time sufferer, and one day I reached "my bottom". I reached out for help, and I got just what I asked for! I no longer suffer, and my music is now tighter, louder, and punchier because I asked for the help that I needed so badly.

First of all, let me explain what compression is, what it does, and then what the parameters actually do to music that we push into them.

Music consists of all types of sounds and notes. Sometimes the louder hits like drum snares and picked bass notes get recorded, which is all too common. These loud notes can stick out, and get in our way. We can't raise the volume level of these tracks because they will distort, and peg the output volume level meter bridge. We need to find a way to lower the louder hits without loosing anything else!

Compression is used in music to lower or remove the louder volume hits and/or notes in a song. This then brings the overall volume ride along a certain chosen level rather than having loud peaks and deep quiet valleys. When we do this it smooths out the volume, and it can actually make the music feel louder and tighter.

If you have a piece of music that contains some very loud snare hits, you can only set the volume to a certain level before it distorts. If you turn up the master volume level so that you can hear the rest of the music, the snare hits will distort, and if left in our song it will result in blown out speakers in our cars. Lowering these "transient" snare hits will allow us to raise the master volume level of that track as we master it, which increases the overall volume level of that track. The snare hits will now sit nice in the track, and the rest of the music recorded on that track will be louder, or more present.

This is a crude example of what a compressor can do for us, but it is a good one! The same is true for a bass track. A compressor on a bass track can tighten up the sound, and allow it to sit in the track all the better. By lowering, or compressing, the spikes caused by pics or hammer-ons, we can raise the overall level without distorting.

Using a compressor on a master stereo output track can make magic! A master track, in this example, is the last chance to control spikes in volume in the stereo output . All of our recorded tracks go through this master stereo track and this is where we can add effects like reverb, compression, and other major stereo effects before the output leaves the recorder. This is the final master mix stereo track. The perfect amount of compression at this point will iron out all of the unruly peaks, and supply us with a more powerful, louder master mix down.

What are these perfect amounts of compression? What do the titles of the parameters that have knobs and sliders mean? Let's dive in and find out!

As any type of effect unit there is usually an input level, as well as an output level. These are a "no-brainer", which needs little to no explanation. One thing that I might need to tell is that most often we put compressors in series with our tracks and not in parallel. In other words, we run our music (or our tracks) straight into a compressor, and then the output is not "mixed" with the original music (or tracks). We want to alter the input sound with our compression, not add to or take away from a portion of what is recorded. We do need to find a smooth amount of input and output without pegging the meters, and that will come with an explanation of how the compressor works, and with practice.

The next parameter of the compressor that we should try to dial in is the threshold. Threshold is the volume level, which we choose, at which reduction (compression) happens. So, as the laymen would say, after we set the input and output levels we then tell the compressor at what level of volume we want it to start working. To explain that in my terms, when the snare hit gets too loud, then wham, start working! As the music "crosses the threshold" the compressor starts working. The music that remains below the threshold level is not compressed, or altered.

Ratio is the next parameter that you will need to understand in order to properly use your compressor. The ratio is simply the amount of compression that is applied to the volume spikes(music) that crosses the threshold level that you just set.

The snare hit example that we continue to use will once again come in handy in explaining how ratio works. We just set the threshold to a point that fails to alter any of our music, except for the loud snare hits. Next, we set the ratio, which tells the compressor how much of the snare hit to take away. The ratio has settings like 1:1, 2:1, 3:1, and so on. This is read as "one to one, two to one, and three to one".

Attack is the next parameter on the hit list of explanation. Attack is a groovy term that defines how fast the compressor starts working on the sound, as it crosses the point of the threshold. A fast attack lets very little time pass, if any, before the compressor take away from the volume spike.

In terms of an opposite force, release is the term for the "letting go", or the stopping of the compressing itself. When the effected signal (snare hit) sinks below the point of the threshold that you set, how soon the compression stops doing its' thing is what is called the release. Attack is how fast the compression starts working on a signal after it crosses the threshold, and release is how long it keeps effecting the signal after if falls below the threshold.

Compression can raise the overall volume level of a track by removing the volume spikes. The spikes are what triggered the red "peak indicators" in out output volume meter. The red lights on top of the output volume meter means distortion to you and I. Removing the volume spikes, or the red peak indicators, means that the distortion is also removed. This means that you can now turn up the tracks' volume without adding any distortion! The beauty of compression!!!

To wrap up the topic at hand, I should add that a little compression goes a long way. Over compressing a track is easy to do. Over compressing sounds like pulses to a good ear, and it can ruin a song. Under compressing will result in a song full of instrument volume spikes which results in an overall quieter song. The spikes take up the available room that should be occupied by instruments and vocals. Use a compressor with caution, but try to use them. They add balls to bass tracks, and magically tighten up lame songs. Compressors can be a magical tool but they can also be so addictive that you can easily overuse them, resulting in a flat, mono level song full of irritating pulses.
Whatever you do, keep playing! Tweaking the compressors can only lead to perfection. In no time at all you will be setting the parameters by memory, and for each instrument!

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