Home Studio Equipment: How to Set Up External Compression

What You'll Need
External Compressor

One of the best components of home studio equipment that a composing and recording enthusiast can have is an external compressor. With external compression the dynamic range that audio signals usually have is reduced. This helps bring out the more 'quieter' sounds in a recording and makes those sound audible when the whole recording is mixed, adding high detail to a recording. Setting up external compression can be moderately challenging, but just fine tuning some equipment can reap great rewards for a recording enthusiast. This step-by-step guide will teach you how to go about it.

Step 1 - Determine the Type of Hardware You Have

Before setting up external compression, it is important that you determine exactly what type of hardware you have and will be working with. Most external compressors used in home studio equipment consist of buttons for threshold, attack, release, ratio and output gain. If your external compressor has them too, along with multiple channels, you are good to go.

Step 2 - Set Threshold

By setting the threshold, you are applying a setting or a filter that will determine the level that an audio signal must exceed before the compressor starts working. This works like a trigger. You are setting up the trigger for a specific level of audio. This component of the external compressor usually needs a lot of fine tuning and you need to be very attentive to your meters in this step when audio signals start entering the compressor. Set the threshold to just a few dB. This is the most common setting.

Step 3 - Set the Attack and Release

Just like the threshold behaves like a trigger, there is the attack that determines the time the compressor will take to start compressing after an audio signal exceeds the threshold (measured in miliseconds). The release is the time the compressor will take to stop compressing when the audio signal drops back below the threshold (measured in seconds). The most common position to begin fine tuning in this step is setting the attack at 5 ms and the release at 1 second.

Step 4 - Set the Ratio

You have to set a compression ratio. The ratio determines the amount of compression that will occur every time the audio signal exceeds the threshold. A ratio of 2/1 will thus compress an audio signal 1 dB for every 2 dB the signal exceeds the threshold. In most home studio setups, a ratio of 2/1 is a good position to begin compression, and you can fiddle around a little here and there from this point on.

Step 5 - Increase the Output Gain on the Compressor

Most of the time, home studio equipment workers make the mistake of increasing the audio output only on the preamps and forget that for better compression, it is the output gain on the compressor that needs to be increased, no matter how much gain you have in the audio signal reaching it. To balance your audio, use the output gain on the compressor now and set it at the optimum point that you require. You are done setting up external compression!