EQ Before or After Compression-Which One Should You Put First?

One of the most common questions I get from my students is, “Which comes first, compression or EQ?”  To understand where to put your compression and EQs, you need to understand the bigger picture. You need to understand the “signal chain”.

     The signal chain starts at the microphones and ends at the speakers. We can trace our signal and everything it goes through on the way including pre amps, noise gates, compressors, EQs, and effects (reverbs, echoes, etc)

      I spent more than a decade working in big studios before I ever even touched a computer. On the big mixers, things are wired in a certain order for good reasons. First of all, most big professional boards don’t have compressors on each channel , which means if you are going to compress (and I almost always do) you’re going to have to plug your out board compressor into the insert on the channel. The insert on these boards come before the EQ. If you are going to use compression and use the EQ on the channel, you have little choice but to compress before EQing.

10 things you’ll need to know when ordering your devices in the signal chain.

1)      Think of possibilities from both sides;

     Equalizers do just what you would expect; they equalize frequencies. If your vocal sound is muffled, it’s because your low end and high end are out of balance. To add treble to the track would literally equalize the frequencies giving you a nice balance of high and low end. I try to always think of possibilities from both sides. You can add treble, or remove bass.  I try them both and pick the one I like most. If you are constantly asking yourself “What is too soft in the mix?” try asking yourself “What is too loud?”

2)      Removing noise with your EQ;

     EQs can be used to filter out noise too.  EQs can be used as “high pass” or “low pass” filters. Most people get confused by these names at first. The “high pass” filter filters out low end (or bass), and the “low Pass” filter filters out hi end (or treble). These EQs are named after the analog circuit that makes this happen. The “high pass” filter circuit actually allows the highs to pass, and likewise with the low pass filters.  What are these used for? They are mostly used for filtering out noise. If you record a vocal and you can hear the Bass bleeding through the headphone, or even trucks going by, a high pass filter can fix this. You can filter out all of the lows below the vocal getting rid of the noise without affecting the vocal sound. Likewise, if you have a Bass guitar and above a certain pitch there is nothing but hiss, you can filter that out using a low pass filter.

      Also consider that while the noise on one track may not be audible, (tape hiss for example) if you  multiply it by 10 or even 24 tracks it’s a problem. For this reason I use filters often to be safe. If your recording software came with an EQ it’s likely that it has both high and Low pass filters on it.

3)      Removing noise with gates:

     A noise gate is very simple. When the volume goes above a certain level the gate opens, sound is heard. When it drops below a certain level the gate closes, muting the sound. One of the most common uses of a noise gate is cutting out the noise in between a vocal. When the person sings the gate opens and you hear them, but once they stop singing the level drops and the gate closes, turning off the sound. This cuts out the unwanted noise in between the singing.

4)      Use compression for better balance:

     Compressors squish the dynamic range. This prevents a voice from getting too loud and sticking out or getting too soft and lost. Put simply, it turns up the low volumes, and turns down the high volumes making the volume more consistent. I compress all my tracks and often-times more than once. Compressors can be used for other things too. Such as adding sustain, punch, intensity etc.

5)      Understanding “level dependent” devices;

     Gates and compressors are not Effects  they are dynamic controllers.  Noise gates and compressors are what we call “level dependent” devices. Simply put, this means that if you change the volume going into one of these devices you’ll change the way it works. Increasing the level going into a compressor will give you more compression. Decreasing the input will cause you to have less or even no compression at all.  Increasing the input to the noise gate will cause the gate to work differently, or even stop working. Decreasing the input could cause the whole track to be muted. For this reason you’ll want to be very careful of any changes you make to the level going into these devices.

6)      Gate out unwanted noise before you compress;

       If you were to compress a vocal before gating it the compressor could turn up the headphone bleed in between the vocal making it difficult or even impossible to gate out.  For this reason I always gate prior to compression.

7)      Filter out noise prior to compressing:

      It’s also usually easiest to filter out any low end or high end noise prior to compression rather than having the compressor turn the noise up first.

8)      Compress before EQing;

     EQs actually change the level. Adding or removing bass or treble from the vocal will actually make it louder or softer. This is why EQs are most commonly put after compression.  If you put your compression after the EQ, changing the EQ will affect the compression. If your EQ is after the compressor, then changing the EQ will have no effect on the compression.

9)      Listen to the EQ of the sound while adjusting your compression:

      Another reason to put EQ after compression is that the compressor actually changes, and can even fix, EQing problems. Remember compressors turn up the soft parts and down the loud parts?  If you record a six string acoustic guitar and then compress it, the compressor can turn up the quieter strings and turn down the louder strings making a nicer balance. The same goes for EQ.  Good compression can turn up the low volume frequencies and turn down the louder ones making for a nicer EQ balance. Either way the compression IS going to change the EQ. So if you EQ after the compressor you’ll know what needs to be fixed.

10)   There is no “right and wrong way”;

      To limit your possibilities would limit your quality. However, you should know how things are typically done so that if you make any changes you’ll know what to listen for.  For example if you do put your EQ before a compressor, make sure you are aware that every time you change that EQ you change your compression.  Some people gate while recording, but I have never been that brave. If the gate cuts off a vocal you will have to re sing it. So I always gate while mixing.

    The most common way I order my processors is Filters—Gate—Compression—EQ—Effects.

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