EQ vs. Compression... which comes first?

was curious to know if anyone can shed some light on which of these processes typically you put first and why? Can someone explain to me the workflow differences and how the sound is effected when either of them goes before the other?

I would say this is almost the MAC vs PC argument of the audio engineer world.

I personally love using the EQ before the compressor to HPF and then use the EQ after the compressor in order to do any boosts.

Just depends what you want really, the compressor will only compress the frequencies you’ve sent into it, so if you’ve EQed it first then what comes out of that EQ will get compressed.

Or you could EQ the compressed sound after, or both.

It really doesn’t matter which way you have it, do as you please.

do what sounds better for your situation.

To be honest I always compress first, I don’t know why that’s just the way I do it. Would be interesting to see if there is any difference eq first

[quote]howiegroove (04/01/2011)[hr]do what sounds better for your situation.[/quote]

Understood… but it would be helpful to have a rule of thumb to help speed up workflow instead of meticulously switching the two effects back and fourth all of the time… :hehe:

In this instance I don’t think there is a ‘rule of thumb’ really.

[quote]Roben (04/01/2011)[hr]In this instance I don’t think there is a ‘rule of thumb’ really.[/quote]


This is interesting:

From here: http://www.kvraudio.com/forum/printview.php?t=183103&start=0


Kim (esoundz) - Mon Jun 25, 2007 6:19 pm

Van_Mocen wrote:
Hey there,
I’ve heard many people saying that there is an order on a mixing desk when it comes to add affects by insert. Some people reckon that EQ comes first, followed by compression, etc and some of the effects should be put on the pre-fader and others on the post-fader. Can anyone give me an idea of why this happens ? I know that in some cases it’s better to put put compression after reverb (or is it the other way round?) so that the reverb trail is not compressed as well… well, i’ll leave it to ya. cheers!

As Mr Twin wrote, there’s no absolute “right” or “wrong”. However, there is an artistic judgement you have to make, which requires an understanding. Taking your examples:

EQ versus Compression:
The order in which you use EQ and compression will depend on the sound, what you want to do with the sound, and the rest of the mix. By using EQ first, followed by compression (sound->EQ->Compression), you are adjusting the frequency spectrum of the sound, then applying compression to the adjusted sound. You might think of this as “compressing the EQ”. This is useful because the compressor will respond in a natural and predictable way because it is operating on what you hear. You can use the EQ to remove problems and shape the sound for the mix, and the compressor will respond to the “fixed” sound instead of the “raw” sound. The downside is that sometimes a compressor will adjust the percieved frequency response of a sound (usually by reducing the low end or the high end), and it’s not as easy to compensate for it with pre-EQ.

Conversely, by using compression first, followed by EQ (sound->Compression->EQ), you are adjusting the dynamics of the sound, and then adjusting the frequency spectrum. You might think of this as “EQing the compression”. This can be useful if your compressor is reducing the percieved high end or low end of the sound frequency spectrum - the EQ can compensate for any “funk” the compressor is adding. The downside is that the compressor is not responding to the sound you hear, which means it might not sound as natural or predictable. As an extreme example, your sound might have some significant low end rumble or resonance - if you compress before EQing, the compression will respond to the rumble or resonance even if you greatly reduce it with post-EQ.

A hybrid approach might look like EQ->compression->EQ, where the first EQ (before compression) is used to address any problems in the sound and shape it in the mix, and the second EQ (after compression) is used to add any final touches or compensate for compression “funk”.

Which approach you use entirely depends on your sound and your mix. It’s important to understand how it works though, so you can make an informed artistic judgement.

Compression versus Reverb:
Like EQ and compression, it might be helpful to look at this as a choice between “reverbing the compression” (sound->compressor->reverb) or “compressing the reverb” (sound->reverb->compressor). Reverb is usually an additive process - it adds a component (the reverberation) to the existing sound. If you add the reverb last (after comrpession), you’ll be able to produce a conventional, natural sound. That’s because the signal being sent to the reverb has the same (or similar) dynamic response to the final sound we’ll hear in the mix. Also, the added reverb itself isn’t being significantly processed, which means it will sound close to what the reverb designer intended.

By doing it the other way - “compressing the reverb”, you are directly altering the dynamic rseponse of the reverb itself. This is not a common process, but may be useful for achieving special effects or unnatural ambiences. For example, smooth deep compression on a long reverb tail may lengthen the reverb tail or make it sound “deeper”. More aggressive comrpession can create a very unnatural pumping effect that emphasises the reverb without washing out the original sound.

The best thing to do is to experiment, listen and learn.

Pre-fader versus post-fader:
Without going too deep into mixer topologies, the channel fader sets the gain (you might also think of it as the level or volume, though it’s not quite the same thing) of the sound going into the mix bus (also called the 2-bus or the master channel). Placing effects before the fader (pre-fader) mean that those effects will “hear” the same level, no matter what the fader is set to. Placing effects after the fader (post-fader) will mean that thsoe effects will “hear” a level depending on what the fader is set to. This is particularly noticeable with effects such as compression, which respond differently depending on the level of the sound. If you set up yoru compressor pre-fader, then it will behave the same no matter what the fader is set to. On the other hand, if you set up your comrpessor post-fader, then higher fader gain will result in more compression and lower fader gain will result in less comprssion. In effect, you will use the fader to simultaneously set the audible volume of the sound in the mix AND “drive” the compression. Normally this is not such a good idea beacuse it makes it more difficult to fine-tune the mix (changing the volume changes the compression too).

Post-fader effects are typically not used often, except for sends (also called “aux sends” or “FX sends”). The “send” effectively duplicates the sound and sends one copy to the send channel (the other copy is sent through the original channel as normal). If a wet reverb is applied to the send channel, you’ll have two channels making sound - the original “dry” (no reverb) channel, and the “wet” (reverb) send channel. If the send is post-fader, then the sound level that is sent to the reverb depends on the fader setting. This way, if you adjust the fader (to fine tune the mix, or perhaps automate a fade in or out) the RELATIVE level of the reverb stays the same. On the other hand, if the send it pre-fader, the absolute level of the reverb stays the same (so if you turn the fader all the way down, you’ll still hear some reverb, and if you turn the fader all the way up, you’ll hear less reverb relative to the original sound).

Again, the best thing to do is try it out. Listen and learn.

Hope that helps. Smile



yah i almost always do compression first then eq. dunno why. no rule of thumb really. and I don’t do this for every sound. but the first thing I do usually is throw a compressor on a synth.

I put an EQ in everything automatically and I have been guilty of EQing the life out of things (I am getting better at being subtle). I, now, don’t add a compressor to anything unless I have a good reason until I get to the mixdown, then I use them as lightly as possible. These two things, easing the EQ and waiting to add compression, have really improved my mixes - I still have some way to go though.:slight_smile:

simple cut before compression and boost after compression.

Try not to compress everything guys, if it doesn’t need it, don’t use it.

[quote]Roben (05/01/2011)[hr]Try not to compress everything guys, if it doesn’t need it, don’t use it.[/quote]

theoretically speaking nothing programmed should need a compressor so where and when would you recommend using one ?

also how would one know when to use a compressor ?

I can hear Roben shuffling through his Computer Music mags…  :wink:

[quote]Roben (05/01/2011)[hr]Try not to compress everything guys, if it doesn’t need it, don’t use it.[/quote]

Actually this is advice that would have been of great benefit to me earlier in my learning.

[quote]Jon_fisher (05/01/2011)[hr][quote]Roben (05/01/2011)[hr]Try not to compress everything guys, if it doesn’t need it, don’t use it.[/quote]

theoretically speaking nothing programmed should need a compressor so where and when would you recommend using one ?

also how would one know when to use a compressor ?[/quote]

I would have thought you’d have already known dude :smiley:

But for the purpose of everyone else, just ask yourself ‘what is a compressor?’. Do you know? Seems to me like a lot of people out there use compressors without actually knowing exactly what it does.

Which really is bad because if you’re putting on a compressor without having any idea what it does or how it can effect the sound then you ‘could’ unintentionally ruin the sound you have.

[quote]howiegroove (05/01/2011)[hr]I can hear Roben shuffling through his Computer Music mags… ;)[/quote]


Haven’t read one of those for a while now, although i do have my Future Music subscription :slight_smile:

if essentially a compressor is simply a volume controller how can a compressor ruin the sound ?

is there anything else i could do instead of using a compressor if i don’t know what I’m doing ?

and how can i control the sound with out and peaks with out a compressor ?

JOn is right.  All a compressor is, is a device that turns volume DOWN when it gets to a specific point.  The reason it sounds louder is because of the makeup gain.  A compressor wont destroy your sound but will squash your transients.  This might be a desired effect too…who knows.  You need to practice to know.


Well Jon, I know you already know what a compressor is and what it does, so since you’re humouring me, i’ll humour you too, since it’l no doubt benefit members of the site possibly reading this.

[quote]Jon_fisher (05/01/2011)[hr]if essentially a compressor is simply a volume controller how can a compressor ruin the sound ? [/quote]

Firstly it comes down to what you’re compressing, is it a single sound hit? Or a audio loop? Or even a synth midi?

Compression at it’s core is about leveling out the audio that’s going into it. So for example, take an audio loop, in that loop there will be low and high peaks at each of it’s transients. Some pretty hard compression on that could take those lower peaks and those higher peaks and level them off to peak around the same level, of course how much is all dependant on how much you’re compressing it.

Why can this be bad? Think of a live drummer, when he hits his drum not every sound will be hit at the exact same velocity, this is what is known as ‘dynamics’.

If you’re hard compressing, you’ll take away those dynamics, now this can be a good thing if you want that effect, but generally it’s not nice, especially if you’re doing it to a full track, it takes away that organic sound. A track with good dynamics is much more enjoyable to listen to than a track that is heavily compressed. *google ‘loudness war’.

How about a single sound? Ok well for a quick example lets take a kick sound, compressing that kick with a fast attack will take away the punch of the kick, this ruins the sound as with kicks you want them to be punchy.

There are plenty of other ways you can ruin audio with a compressor if you don’t know what you’re doing so it’s important to watch the video above and get an idea what each of the parameters of your compressor does before applying it to your sound.

[quote]Jon_fisher (05/01/2011)[hr]

is there anything else i could do instead of using a compressor if i don’t know what I’m doing ?


Your question doesn’t make any sense? What are you trying to achieve?

If you don’t know what you’re doing then find out what it is you’re trying to achieve and turn to YouTube or the Sonic Academy forums, they are your friend.

[quote]Jon_fisher (05/01/2011)[hr]

and how can i control the sound with out and peaks with out a compressor ?[/quote]

If you want to control the peaks then a compressor or limiter is there to help, but have some kinda idea what you’re doing otherwise you’re just dropping something willy nilly onto something without any idea why or what it’s doing, or even if it’s doing anything at all.

For example, if your threshold is too high and the peaks of the audio going into it isn’t reaching that threshold then you’re compressor isn’t actually doing anything as it will only apply it’s compression to anything that reaches the threshold, not under.

If you don’t want to use compressor or limiter then you could manually automate your volume along that particular channel, which in some cases can even be the better option (depending on the sound your modulating and the effect you’re trying to achieve).

If you don’t know what compression is or what it does and you’re serious about music production, i’d advise doing some serious research.

On all that note, just to remind you that how your attack, release, threshold, ratio is set will change how your compressor acts upon the audio, and can - if not used properly - dramatically change the sound for better or for worse.