Most of us in the recording industry have a solid understanding of how compressors work. We know how to tweak the settings to achieve our goals in a mix. But even the most well-informed of us are hanging on to some misconceptions about the technical aspects of how these crazy machines function.
Let's start with the most simple myths and misguidance that's out there and move to increasingly complex concepts. There's something in here for everyone. A full understanding of these myths will improve your mixing and mastering. You'll add a few techniques to your process and correct some harmful ones... each incrementally improving your mixes until your competitors are sending spies to your studio to figure out exactly what gear you're using and how you're using it.
Take your time to consider each point. They are so ingrained in our minds that it's easy to gloss over it and dismiss it, but what you'll find here is nothing but the truth behind the veil!
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It might seem this way but the truth is the exact opposite! You're setting your threshold and compression ratio and suddenly all of the quiet parts sound louder. This is true only after you've adjusted your makeup gain to compensate for the fact that you've actually just made the loud parts less loud. Think about it... it's called a compressor for a reason.
No! It's true that compressors automatically ride the gain in a fashion to reduce the variation in dynamics between quiet and loud parts. But if you're smashing your volume to reduce this dynamic range so that you can choose a single volume setting for your entire mix, you're losing a lot of opportunity to breathe life into your mix. Some syllables in your vocals might need a slight boost even after compression to be more intelligible. You might need to increase the volume of your guitars as your song transitions into the chorus and more elements are added to the mix. Don't create dead, lifeless, robotic mixes! Take advantage of every tool you have (and need).
There's nothing worse than amateur mastering (and it doesn't even deserve THAT label). A hobbyist will have created his best mix and then want to increase the overall volume of the track to match those of professional releases before he slings it all over the internet. So he slaps a limiter on his master output and pushes up the volume, letting the peaks literally get chopped off so the average volume is increased.
People literally agonize over every detail of their mix and gain staging to make sure there's no clipping, and then clip off 50% of their dynamics during their "mastering" phase. Sure, use a limiter, but first make sure you're compressing in the mix as much as you need and then apply additional compression during the mastering stage. If you can gain an additional 2dB of average volume with small 2:1 ratio and a high threshold, why wouldn't you do that instead of clipping off the tops of your waveforms? Always achieve your volume gains musically first!
They are definitely complicated but nowhere near stupid. Don't dismiss the power of multiband compression just because it takes a little more time. This especially goes out to anyone learning and practicing mastering. A common problem is to wrap up your album or mix and think it's all good. You don't even bother archiving your source material because your mixes are so good. Then you start hearing your songs on other sound systems and different rooms and realize you've added way too much bass or not enough compression to tame their peaks.
Is it too late? Not by a long shot if you're willing to use a multiband compressor. You can reduce the volume of the bass frequencies as a whole with EQ, but you can't shape the peaks or allow transients to pop through with an equalizer. This is why you see some re-masters of classic releases coming out. It's never too late to fix up cruddy mixes, but you need the right tools and this is the precision scalpel.
Yes, they all do the same thing, which is taming your audio signals dynamic range. But how they do it is not remotely the same. The fact that you see professionals arguing over which is the best vocal compressor constantly should clue you in.
The reality is hardware compressors have different electronics inside of them. Some are solid-state. Some are solid-state with transformers that add a warm saturation to your signal. Some have vacuum tubes that add harmonic distortion. Some are limiting amplifiers. Then you move over to software compressors. Each of these plugins uses different algorithms to emulate different circuitry. The default Logic Pro compressor offers you five or six different models to use. Why would they even bother if they all sound the same?
The problem is that amateurs can't hear the difference or don't bother to listen for the difference, and the myth continues to get perpetuated. A lot of this has to do with simply not being exposed to quality compressors and only hearing cheap ones.
I mean... sure, you can do that. You can try to simplify your life by giving up 50% of your compressors ability to sculpt your sound. So many beginners will set their attack and release to the fastest settings and go from there. They give up the ability to sculpt or even allow initial transients to exist. They can't figure out why their sustained bass notes feel like they are wobbling and pumping on the tail ends of the sounds.
Don't forfeit half of the parameters available to you out of laziness. Not every source needs to be treated the same, especially when the lengths of notes vary so drastically.
Who comes up with this crap? "If you can't fix it in the mix then it's a problem with your orchestration and arrangement." No. For instance, take a kick drum and bass guitar. You might meticulously choose ones that have their fundamentals or harmonics in slightly different ranges, but "slightly" only helps so much. And there's no reason to use an EQ to destroy your bass tone throughout the entire song just so those relatively few moments when the kick fires sound better.
Sidechain compression is absolutely not cheating or cheap. It's an advanced technique. The same people who say this are happy to line up a de-esser to fix problems in the vocals. Ducking your bass when your kick hits isn't cheap, it's smart. Turning mixing into a purist or morality issue is silly. The only thing that matters is the end result.
Absolutes like "never" and "always" are attempts at shortcuts that always result in lesser results. This advice comes from the "always record dry" crowd. That makes sense in the digital age and I understand why people say it. If you add EQ or reverb before the converters, then you can't undo it. You're stuck with that choice. But it's not always an "on or off" scenario when it comes to compression.
Imagine that you're recording an extremely dynamic rock singer. He gets excited and delivers the world's most perfect and emotional performance ever, but unfortunately he got too loud and distorted. You could have saved this from happening by using a small amount of compression while tracking. Nobody said you have to completely crush the dynamics during tracking. You can use it as a safety measure for when a vocalist wavers too close to the mic, for instance.
First of all, those are very subjective words that some people repeat and don't even understand what they mean. This is generally referring to a more pronounced, warmer, controlled bass region. And a compressor doesn't always achieve this.
Think of a synthesizer bass line with tons of distortion so the harmonics can pop out in the mix and make it easier to hear. You may slap a compressor on the track and set a threshold that enhances your harmonics. Too deep of a threshold removes them too much. So what you're doing is sculpting mid and high frequency sounds and never touching the bass portions. They never get sculpted into a rounder, smoother, thicker, fatter sound.
It's like using the backside of a hammer to pound nails. Sure, you've got the right tool for the job but you're using it completely wrong.
This isn't true, although I'm pretty sure I've typed this exact thing on this very site before. It's the easy way to understand it. What the attack setting is actually doing is setting up the time it takes for the compression to ramp up to 2/3rd's of the compression ratio you've designated. So while it's definitely a sort of delay to full compression, it's not a delay to starting the compression. The inverse is true for the release.
I should place a disclaimer here or I'm perpetuating another myth. The 2/3rd's value is an average estimate. There's no actual standardized value here so every compressor might vary a bit from that number. But that number is far closer to an absolute truth than believing that there's a complete delay to starting or stopping. As soon as your signal crosses the threshold, the process begins regardless.
There's a good chunk of mixing and mastering knowledge wrapped up in trying to unravel these misunderstandings surrounding compressors. There's a handful of shortcuts you can stop using and a boatload of techniques you should start using, despite some prevalent misguidance out there. These myths are out there because a lot of people are lazy, the topic is complex, and most importantly because some folks don't want their competitors to get the upper hand...
Use the tools at your disposal properly and effectively to cater to yourself, your clients, and your listeners. If someone doesn't fall in those categories, then their opinions don't matter!