5 Compression Tips For A Professional Sounding Mix



Compression is something we've all struggled to get a handle on. Mainly because it's a difficult topic to wrap our heads around and fully understand. If you've been struggling with compression whether you know you've been or not. You're in the right place. We're going to share some compression GEMS with you. 

What is a compressor?

A compressor is a device or software designed to reduce the gain of a signal once that signal hits a pre-set threshold. This also reduces the dynamic range of that signal (dynamic range is the difference between the loudest peak of that signal to the most quiet peaks.) While that may sound like it'll make things less exciting it's actually a good thing because it will lower the louder peaks and even out notes that might stick out so that you could bring up the over-all volume on that signal while minimizing the chance of it clipping.  

Now, just as with any good thing. Too much can be bad and even damaging. So you want to make sure you're applying enough compression to your signal to control it but not so much that you kill it. 

Most compressors will have a meter to show how much Gain reduction or 'GR" is being applied to the signal. You should keep an eye on this but you shouldn't rely on it completely to make decisions. Use your ears too and overtime you'll learn what compression sounds like and be able to hear when you're over doing it.  

When do you need compression?

When ever you have material with a wide dynamic range that you want to control. When you mix you want control and over-all balance. You don't want anything to stick out too much or poke holes in your mix which will make it inconsistant. 

Compressor Types and Controls. 

There are 4 types of compressors. I'm going to go through them and give you practical uses for each. 

FET Compressor: FET (or Field Effect Transistor) compressors tend to have the fastest attack times compared to other compressor types. They usually have a rich punchy tone and can be driven to get some nice distortion.

What's it good on? These are generally good for vocals, drums and guitars.

What's a good one? A popular FET compressor is the 1176 which can be found in hardware and software form.

I personally love and use the CLA76 from Waves for in the box mixing. For hardware it'd be hard to pass on the real thing but if you're budget concious Warm Audio has an 1176 style compressor that is pretty awesome. 



VCA Compressor: Voltage Controlled Amplifier is a compressor that reacts to its input voltage. This type of compressor is usually more aggressive when it comes to gain reduction than others. So basically it attenuates volume based on the level it's fed. 

What's it good on? These are best suited for your stereo busses to glue tracks together but can be used in a variety of ways like when you want to catch heavy peaks. Mainly because it's snappy.  

What's a good one?  I would have to say the legendary SSL G series. Reason users have a software version of this built in. But Waves' version is pretty bad @ss too and I can't sleep on the UAD version either. I personally use a hardware version for my stereo bus from Warm Audio called Bus -Comp on my final mixes before mastering. 

Optical (Opto) Compressor: Opto Compressors use a light source inside to trigger compression. The light source is triggered by the level of the signal it's receiving. So as the light inside glows the compressor attenuates the signal. These are typically slower and smoother as well as more musical and pleasant. 

What is it good on? Because of its slow and smooth characteristic Opto compressors are great for vocals, pads and anything you want present and level. These are also good for adding color to a signal.

What's a good one? The Teletronix La2a comes to mind but if you don't have a couple thousand dollars (ahem 8k) laying around to pick one up, the software versions are great too. Waves offers 2 that I use frequently which are the Waves Renaissance Compressor and the CLA-2a. The Ren-Comp can be switched from Opto to Electro mode and offer quite a bit of warmth to for vocals. 

There are a couple of less expensive hardware versions but I haven't tried them out my self yet so I won't comment on them. 



Variable Mu Compressor: Is a tube compressor. It relies on the tubes inside to control the gain reduction which gives it a smooth character. The louder the incoming signal the more compression is applied. How ever this type of compressor isn't as aggressive as others so you would use this type of compression to balance out a signal rather than catch peaks. These are also good for adding warmth and color. 

What's it good on? These are good for mastering as well as guitars and room mics or drum overheads because of their warming qualities. These are also great for gluing a track together. 

What's a good one? The Fairchild 670 (drools) but these can go upwards of 4k for compressors modelled after one.

Software emulations do a pretty good job of nailing this one down though. Waves has the PuigChild 660 & 670 plugins and I personally like and use the Klanghelm MJUC JR which is FREE. 



Which compressor should I use? Use the right tool for each job. Experiment and feel out which type of compressor works better for you on different sources. There are no set rules, only yours and others experiences with different material. In my experience and to my personal taste when mixing, I like to use the following (but I'm not chained to these and will try to quickly pick up if something isn't working and adjust to serve the overall work.)

On Vocals: I like to use FET and Opto compressors

On Drums: FET style compressors do it for me. I like my drums nice and punchy.

On Bass: I like 1176 type compressors followed by La2a style compressors

On Guitars: FET type compressors

On Synths: I'll usually use FET type compressors here but synths are vast and can be anything that serves the sound. 

On Drum Busses: VCA style

On Master: Variable Mu



Typical Controls found on a compressor.

Compressors won't all have the same controls. Some will just have two knobs, some will have knee instead of ratio, some will have make up gain instead of out put so it's best you know what each of these does. 

Input: Controls how loud the signal is coming into the compressor

Output: Controls the level coming out of the compressor 

Threshold: When the compressor starts its dance. So if you have -6db of signal and the threshold is set to -3db then nothing will happen. But if you start to pull that threshold down to let's say -7db you'll see or hear your compressor start to work.  

Ratio: How much gain reduction is applied to the signal once the threshold is met. For instance: 4:1 ratio means that for every 4dB the signal goes past the threshold the compressor will out put 1dB. 

Knee: You'lll typically see soft or hard knee if you have this control. It dictates how gradually or hard the compression kicks in using a slope. 

Attack: Tells the compress how soon after the threshold has been reached to start working. 

Release: Tells the compressor when to ease up on the gain reduction.

Make up gain: you might have this instead of output and this will typically compensate for the volume lost during compression. 



How to use a compressor: 5 tips from my experience with compression.

1. Gain stage first. Don't reach for a compressor (or anything else) until you're done gain staging your track.

2. Know why you're using a compressor. Meaning, you've listened to the material and heard something stick out or you want to add a certain flavor to a certain signal. 

3. Be mindful of your attack and release times. Compressing a kick or snare with a fast attack time could smash the transient part at the beginning to bits which will reduce it's impact. Having too slow a release time can make the signal sound like it's fading as the compressor gets hit with the next transient. 

4. Compress in context. Similar to eq you should limit processing your signal in solo. So you can hear, in context to the rest of your material how the changes you've made affect the over-all sound.  

5. Don't limit your self to just one. I use serial compression on almost anything I need to compress. Why? because it gives me added control in a way that sounds transparent and pleasing.

For example: On rap vocals sometimes I'll use two 1176 type compressors in series. And I'll tweak the attack and release until I get the desired result. Usually one will have a higher ratio than the other to catch the peaks and Im only trying to get between 3-6dB of compression. Then I'll follow those up with a LA2A type compressor (which is an opto compressor)  Set to compress instead of limit just to smooth things out a bit. This also works with one 1176 in front of the LA2A or in reverse with the LA2A in front, set to limit instead of compress.

Depending on the material I'm working with I might choose to use a dynamic eq as well before the compressors which gives me control over specific frequecies that may poke out too much so those frequencies dont drive the compressors too hard. 

Conclusion: A compressor is a very valuable tool to have in your arsenal. If you learn how to use them properly they can save you a bunch of time and effort but the biggest tip I can give you is this... learn how to use the stock compressors in your DAW before going out and spending money on hardware or software. Because if you can't make it sound good with the stock plugs you'll still get the same results with something "better" but now you're out a few bucks too. 

 When you've got it all figure out or atleast in the right direction...Take 10% off of your purchase at Waves.com on us 

Get yourself something nice. You deserve it. 

If you're on a budget or just looking for some free plugins check out 

Top 6 FREE VST Compressors


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