Compressors seem to confuse a lot of people in the beginning, they certainly did me! Here is some helpful information concerning using a compressor in your mixing to help get you started. I will have other blogs on compression, so keep a look out!
1. Decide what you want to achieve. There are really only 4 reasons for using a compressor - control a dynamic signal, add punch or impact, change the sound, create an unusual effect. Make a decision on what your goal is, which one of the four you would like to achieve. Keep listening with your final goal always in mind. Here is a neutral starting point: 2:1 ratio; 75 ms attack; 100 ms release.
2. Overdo to begin with. Pull down the threshold until it starts working. It can be helpful to start with exaggeration. If you're having to turn the threshold way down - boost input level instead. Exaggerating can help get settings right.
3. Listen. Fine tune settings keeping end goal in mind. Once you get close, adjust the threshold.
4. Listen again and balance different settings against one another. Higher ratios usually need higher thresholds. Lower ratios usually need lower thresholds.
5. Experiment. Don't be afraid to change a setting. Just keep listening! Radical amounts are common: 15-20 dB for electric guitars, room mics, drums and even vocals.
For a smoother sound - Use faster attack and higher ratio (But don't lose energy & excitement)
To reduce 'bounce' - Use shorter release time & ease off threshold, or use a lower ratio. Bounce is when you hear the level ducking as the compressor kicks in and then springs back up when it releases.
To add punch - Use a higher ratio, slightly longer attack and shorter release times, but watch out for pumping. Pumping is where the end of the note is louder than the start. Also when adding punch, be careful not to introduce any distortion.
If you add stereo buss compression - be gentle - 1.5:1 and only 2 - 3 dB of gain reduction.
Don't be afraid of using compressors. Experiment with them until you understand them. Try this experiment: print a bass track with heavy compression. Compare the original audio track with the compressed audio track. This will help you understand just exactly what the compressor is doing. You will see a visual representation of what your ears are telling you.
Compressors are a vital part of making music. We use them while tracking, mixing, and many times both tracking and mixing.
I hope this helps! Peace - and as always - make it a GREAT day!