Lessons in Compression Part 2

Still not quite sure on how and when to use a compressor in your mix? Hankering for some more details on how you can use them to sweeten up your tracks? Well, read on as we continue our introduction to the murky world of dynamics processing...

There are two main ways of using a compressor - there's "problem solving", in which you want to achieve a particular solution, and "creative" use, which involves radically changing a sound, and generally will utilise some fairly extreme settings. We'll come to creative use later - but first, let's stick with those extreme settings for a minute.

Most people know the basics of what the various things on a compressor do, so we won't dwell; attack is how long it takes to kick in, release is how long it takes to reset back to zero, threshold tells it when to start working, and ratio by how much. But it's not always easy to figure what this actually means in the real world, so here's a useful trick when putting a compressor on your channel. Set it up initially with a high ratio (let's say 15:1 or more) and then bring down the threshold so that you're taking off a large amount of volume - maybe 20dB.
This will make your channel sound like a horrible mush. So don't leave it like that. However, it will also dramatically emphasise the effect of the attack and release. Change these settings and you'll see that a long release (hundreds of ms) will track slower volume changes - like the difference between your singer's loud chorus and quieter verse – while a short release will reset rapidly between notes, evening out the level of individual hits, but leaving the larger scale stuff untouched.

At the other end, a short attack (i.e. 10ms) will cut things off sharply like a limiter, making your drums (for example) able to achieve a higher overall level, albeit at the expense of a lively, dynamic sound. A longer attack (i.e. 40 - 50 ms) will allow a transient through but may squash the body of the sound; in this way you can control the overall level while retaining a certain natural feel. Alternatively, you can use this setting to emphasise transients.

Listening to the channel like this should give you a clear view on what the compressor is really doing. So once you've tried various attack and release settings, and they're now doing exactly what you want, back off the threshold to a more moderate level. "Moderate level" is, of course, relative and depends on what you're processing, but you should alter it in conjunction with the ratio.

For something that needs to feel kind of natural, like a vocal, acoustic guitar or even an old soul sample, then it's important that your compressor isn't suddenly yanking down the volume. So a low ratio (like 1.5:1, or even less) coupled with a low threshold (such that the compressor is removing around 3dB) will mean the compressor is triggered often, and consistently nudges the volume down. This will feel more natural than a higher threshold with higher ratio; the overall effect may still be that the volume ducks by 3dB, but if it happens abruptly then the effect may not be very musical, and unsuited to a more delicate sound. It might sound great on a bass or drum track though; something with a bit more energy.

People often wonder where in the signal chain the compressor should go. As always, it depends, but as a general rule of thumb any 'fixing' should go before the compressor. For instance if you've got some hiss on your channel, then a compressor can make this sound louder - so try to remove it with EQ, gate or noise reduction before it gets to the compressor. On the other hand, if you want to boost part of your sound with an EQ, then you might find that the part you've boosted is now triggering the compressor, and being turned straight back down again. So in this case the EQ should go later.

It may sound advanced, but don't be afraid of having two compressors one after the other. If you feel you want to to tame some peaks, but also control the overall level of a part, it's no crime to have a compressor with a short attack and release followed by one with longer settings. But be careful - the more compression you use, the easier it is to accidentally squash the life out of a sound!

Creative use is a completely different kettle of fish, and you can pretty much discard the rule book. For a good example of the "extreme" settings mentioned earlier, take a listen to someone like Flying Lotus or Rustie. Check out the way pads, FX and hiss drop suddenly out of the mix and then surge back - this is created by having low thresholds, lopping off 15 or 20 dB with a heavy ratio and a long release of 200 - 400ms. For a soft sound like a pad, this can also be triggered with a sidechain input, for instance the kick or snare. Or, you may even set up a channel that has no sound output, and its only purpose is to trigger a sidechain.

Compressors driven hard like this can change the sound dramatically - try pushing a sub-bass heavily through a compressor or two, and you'll hear it create higher frequency harmonics that weren't there before, as it tries to keep up. You can also try some sound design effects - layer up some delays and reverbs on a sound, then squash them hard with heavy compression. Do this a couple of times and you'll end up with a shifting pad or drone sound full of atmosphere.

As we mentioned at the start, compressors can be confusing, and difficult to use correctly. But if you follow some of the tips above, and make sure you're definitely improving the situation with some careful A/Bing, you should find the fog starts to clear a little. So fire up that plugin and get listening!

Lessons in Compression Part 1

The compressor. Possibly one of the most mystical, misunderstood, and yet even simplest tools in the producer's arsenal. It has the power to improve or ruin any mix. Can you be sure you know when to draw for it? Join us for a quick tour of how, why, and when to use a compressor...

Although a compressor is a simple tool - Let's be honest here, it's essentially just an automatic volume knob - For many, it's something that causes a lot of confusion. Much of this is put about by forum users pushing forth received wisdom, and leads innocent people into some strange practises. We could write a whole book on when or when not to use a compressor, but let's look at a couple of basics.

Firstly, not everything needs compression! This might sound obvious to some, but I was recently teaching a student who, as step one when creating a new channel in his DAW, put a compressor on there. Just because, "you know, compressors are good". It's unfortunate that people end up in this mindset, as it will certainly hinder their mixdowns.

So it's very important to consider, then, exactly why you're putting that compressor on your channel. What problem are you trying to solve, or what effect are you trying to achieve? If you don't know, then it's probably best to leave it off for the time being. There's no inherent problem in not compressing things much, if at all. It's only a very recent development that we've been presented with the chance to have compressors on every channel anyway - Until a just few years back, a compressor was a hardware unit and most dance music producers would only have a couple. So they'd have to be a lot more considered about what gets compressed, and how to work with dynamic range otherwise.

That leads onto the other point - With audio production there are many ways to skin a cat, and often a compressor won't necessarily be the easiest way to get what you want. If you have a synth or vocal line with a couple of occasional louder parts that you want to tame, it might well be easiest to just draw in a bit of volume automation at those points, rather than trying to set up attack and release times. Similarly, if you wish to tame a transient on a snare, it might be easiest to lop off the top with some subtle overdrive, which can be configured relatively easily.

In fact, one exercise which I'd recommend to anyone, would be to write a track with no compressors at all. With transient shapers, distortion, overdrive, hard-clippers, de-essers, limiters and volume automation you can achieve more or less everything that a compressor can do, and it will get you thinking more analytically about exactly what you need a compressor for in the first place.

So then - Enough of when you shouldn't be using then, what DO you need a compressor for? There are two main ways of using one (and indeed any effect) - For creative purposes, i.e. to radically change the sound to make an interesting effect, and for fixing sonic problems, or helping things sit in the mix more comfortably. Looking at the latter, a compressor is probably best used on busy tracks when automation or other solutions would be unfeasible. If you find that you can't quite seem to find the right level for a channel – too loud in parts, too quiet in others - Then it's probably a good time to reach for one. Or, if you have a buss and you want to glue the sounds together a little, by letting some smoother sounds duck under some more vibrant ones, a compressor may help here too.

A good place to start would be with the presets on your compressor. If you're new to the compression game and wish to process your drum buss, then see if you've got a 'drum buss' preset and go from there; if you don't think it's doing exactly what you want, then try tweaking some settings (more on these later). But the key things to remember are to make sure you're not making things too complicated, and that you're actually improving the situation. Be ruthless, and make good use of the "bypass" or "compare" function on your plugin. If it's not actually helping, then go back and start again!

So, these are some general tips to get you thinking - Join us next week as we go more into the specifics of ratios, thresholds, attack and release....

The Benefits of Referencing Your Mix

Time to think about referencing your tunes. Ever find that when you're getting your own tracks in the mix, or playing them out in a club, somehow they just don't sound quite right when you put them up against released tracks? Even though they sounded fine back at home? You're not alone! Let's dive in and look at how you can make sure you're getting the right balance...

When I say 'referencing', I'm going to be talking about two different things; there's listening to your track on different speakers and in different environments, and then there's comparing your track with others.

First though, before you even get to that stage, you should take a break. If you've been mixing down all evening, your ears will have gotten used to the track as it stands; anything you do will likely just make it sound 'wrong'. So go for a walk, listen to some completely different music, watch a bit of TV. Better still, leave it and come back tomorrow. Then, load a bounce of the track into iTunes or Winamp, and sit back. You'll be better able to appreciate what the track is actually doing if you can't see the mixer or the arrange window of your DAW; the brain has a funny way of rationalising everything, and it really helps just to listen to the file in a different program than usual.

Once you're happy with your mixdown so far, then you need to fire up some tunes that you think your track sounds similar to - or that you want it to sound similar to! Make sure you've got the volumes matched up so that they all sound the same level, and flick back and forth to compare the differences in the mix (you might find it's easiest to do this in your DAW so you can mute and unmute channels). There are some obvious things to listen out for, like the basic issues of a mixdown; is your snare much louder or quieter than another track? The vocals? On a more subtle note, you should listen out for the overall balance of the track. It could be that although everything sounds good individually, the higher frequency elements of your track are quieter, relative to the bass - which might mean they don't come through so well in a club. Or vice versa, of course.

If yours sounds somehow 'harsher' perhaps, but you can't identify which element is causing it, then it could be that you've been boosting high frequencies on several channels (again, even if they sound fine on their own), and would be well advised to go back in and tweak them.

Pay attention also to whether the other tracks use any cunning techniques with the arrangement - often you'll notice that a track may create space for a vocal by dropping out some lead lines or high frequency percussion; or will program the bassline so that it's not playing at the same time as the kick. This can be a useful way to avoid cluttering the mix, or avoid it sounding 'top heavy' for instance.

Many people find it helpful to use some kind of graphical frequency analyser when mixing down and referencing, and it can certainly help - if you look at one track which seems pretty flat, and yours has a strange spike at a certain frequency, then you may need to consider what is causing it. But equally, you don't necessarily have to go after every little peak in the spectrum - your track has to have some kind of sonic focus after all! You don't want to be mixing all the character out of your beats. And you should always try to trust your ears, rather than what you can see on the screen.

Once you're confident that you've got a balanced and comparable sound, you then need to go and take your new beat, and your reference tracks, and listen to them on other speakers. This is vitally important, as so far you're going to be working around the imperfections of your room and speaker set up. So there could be some issues you've not spotted yet.

If you can, try and listen on a small setup which doesn't have much bass, a bigger system which has plenty, and maybe in the car - car stereos can vary enormously. Some common things to look out for would be the low end - especially on the small system. Can you still hear the presence of the kick or sub on some tiny speakers? At the top end, does your lead or vocal still stand up clearly amongst the tinny rattle of the rest of the track? Is it the same with the released tracks? Similarly, on some boomy speakers, you want to make sure that the low end still has clarity, and doesn't drown out everything around it.

It's a bit of a long and often quite boring process, and one that will mean you get through plenty of blank CDs. But it's necessary if you want your tracks to hold up well against the best out there, so get a notepad and pen, and start listening closely. You may find your mixes start to improve quite quickly!

Be Inspired by "Found Sounds"!

Any producer will know the feeling. You sit down in front of your sequencer, fire up a template, and sit there staring vacantly at the screen, as all the ideas disappear from your head. You're stuck for inspiration. What to do? Here's one angle that could get you moving again...

Before you start producing a track - in fact, it's best to do this kind of thing when you're not feeling inspired or creative, so that you can get on the case more quickly in times of creation - why not try amassing an army of 'found sounds'?

When people mention 'found sounds' it's often easy to imagine that we're talking about avant-garde, experimental noise stuff. But it doesn't have to be like that - they can provide a brilliant source of ideas, details, glitches, rhythms and more, which may give you the starting point you're looking for.

The most common way is to get hold of a cheap sound recorder and take it out and about. This is a great way of getting atmospheres, background textures, incidental effects that you wouldn't otherwise find. Take it to the subway station, walk up a busy street with it, go into the fields and run a stick along a fence. This kind of technique is something that Eskmo used to awesome effect on his recent Ninja Tune album - the result being that it has a very distinctive atmosphere.

If you don't have the cash for a decent field recorder, then just try using your phone - or even the webcam on your laptop. It maybe lo-fi, but what we're after is ideas more than sound quality. So get recording! Back in the studio, time to get the mic out - if you have one. Get anything you can to make noise - hit things with sticks, slap the cat, make weird noises with your voice. If you don't have a mic - make one! Have a search on line for 'contact microphones' - these things can be made for literally pennies from your local electronics store. You can stick them on anything and they'll record the vibrations; put one on the side of a balloon and blow it up to make yourself sound like Darth Vader, put on on the side of a beer can and rip it up to make sounds like a giant car crusher. You can also just stick one on the wall and record yourself making noises like it was a normal microphone. The world is your oyster.

Once you've got plenty of sounds - lets say 15 or 20 minutes worth - then it's time to get busy making them into something a bit more useful. Some, like an atmosphere from a street, can be dropped into a track straight off. Others may want processing, and luckily there's a whole host of plugins to help you out. Try some extreme timestretching and reverb to create sci-fi atmospheres. Or, try using an 'audio quantising' process, such as Logic's Flextime on sounds that have a clicky, glitchy, percussive aspect, to make some crazy rhythms that you can then build a beat around.

Made a crazy metallic weird sound with your contact mic? Stick an autotune plugin on it, to get a melodic riff you'd never have thought about making otherwise! If you have some glitches, try leaving them unquantised and just drop them into a beat, to give a random swing and groove. Any of these tricks can give you ideas to get moving on a track. Or, if you've got something going already, can help you lift it up from the standard beats and bass vibe, into something else entirely. And the best part is - they're unique to you! You can bolster your samples with sounds that no-one else has, and create a signature style.

So, next time you're sitting at the computer wondering what to do, don't just give up and load facebook - get started making your own inspiration. You never know where it could lead...

Let's Get Deep! Using Sub Bass in Music Production

Sub bass these days is one of the most essential aspects to a dance music track - and now that we have decent sound systems and quality rigs in clubs, it's ever more important to get it right. But what's the best way to do it? And what makes a good sub anyway?

We all know what sub-bass is - it's that bedrock of your track, ranging in the 40 - 100 Hz region; either underpinning your bassline or kick (or both). But there are plenty of misconceptions about it, and how you should treat it, so lets clear a few of these up now.

First, a simple sub-bass is a sine wave. That's all. It makes things nice and easy, because there's no need to worry about what would be a good synth to use for sub bass; just load up a sampler with no patch, and use a sine from that. Done! We could go into the maths of it, but essentially any other type of wave (lets say a square wave) - has higher frequency harmonics in it; on a square wave these appear to be the 'corners' of the square. Low pass filter a square wave and you'll be left with a sine again. If people talk about a 'fat' sub, then it's probably because there are higher frequencies in the sound. You might want some of these harmonics though - we'll touch on that shortly.

Because sub bass is such an 'extreme' frequency, there are plenty of technical issues that come into play. A lot of them arise from the limitations of vinyl or club systems. You need to remember that as frequencies get lower, the wavelength gets longer; this means a speaker (or needle) has to move twice as far to create the sound, and will need much more power to push all that air. As such, it's a good idea to try and keep your lowest frequencies above about 40Hz, which is around the notes of E1 or F1. Below this, at the kind of volumes dance music requires, it starts getting increasingly difficult to cut to vinyl (the grooves need to be further apart, limiting the length of the track) - and not all club systems can handle the extreme lows anyway. Your author has first hand experience of playing one of his own tracks in a busy club, and finding that it sounded like there was no sub-bass on the track whatsoever. The sub (on the note of D1) was too low for the club system to handle; it sounded terrible!

Another issue you'll see discussed is that of panning. The accepted wisdom is that you need to have your basses in mono, and this is a sensible option to go for. Vinyl can skip and jump if the deep bass grooves are significantly off to one side; and anyway sub-bass frequencies are below the level that you can reliably tell where they're coming from (the wavelength is longer than the width of your head, for a start). A mastering engineer or vinyl cutter may well decide to mono a mix anyway below around 300Hz if there are any problems with stereo bass - so you'll need to make sure (as always) that your mix sounds good in mono too. And again there can be club problems - many club soundsystems are mono anyway, but even if not, a sub panned hard will only be coming from one set of bass speakers. And that's going to sound weak.

Besides the technical, engineering aspects, you also need to write your subline sympathetically to the rest of your track. This means, for a start, have it monophonic - clashing notes will sound muddy and use up headroom. So make sure the 'release' on your ADSR envelope is tight, to ensure that notes don't overlap. If you're using a subby kick, then try to make sure that your sub isn't playing at the same time - or if it must, sidechain it off the kick to duck the volume, again for headroom purposes.

To return to the subject of harmonics, this is something that can be useful for a number of reasons. You can add a sense of warmth, or 'fatness' by adding in frequencies above the standard sub region - we're talking 150 to 400Hz here - that will give things more of a glow. But, arguably more importantly, they'll help the sub come through on smaller speakers. A radio or an iPod dock will struggle to reproduce frequencies right at the bottom end; not so much of an issue if the top end of your bass is a raging wobble dubstep affair, but if you're writing more of a roller, then it may sounds like there is no bass at all. Get some higher frequencies on your sub and people will be able to hear what it's doing, even if they can't feel the weight. A simple way of doing this is to set up a send to a buss, and then distort it and bandpass filter it around 200 or 300 Hz. This way it will copy the original sound, shouldn't interfere with the low end (as you've high passed it) and will give extra interest for the listener.

Sub-bass is a tricky subject, and it's something that requires practise to get right. But learn the basics and you're halfway there. So, jump straight in - fire up your speakers and get writing those big basslines!

It's a Take! Prime Loops Guide to Vocal Production

With the ongoing love affair between pop, hip-hop and dance music, there has never been a time when the vocal track has been so popular in underground dance music. So read on for some production tips on how to fit a vocal into your own beats...

From dubstep to deep house, from layering an acapella on your future garage track to recording a full session, everyone's looking to vocal music in 2011, and it's not hard to see why. With dubsteppers like Rusko and Benga troubling the charts, and producers like L-Vis1990 grafting R'n'B vibes onto house tracks, we may even have a genuine trend on our hands.

So what are the main points to make your vocal stand out? There are a few things that need to be addressed, but first off, the mistake that your author sees most often is that the vocal is simply too quiet. Pay attention next time you're in a busy shop, for instance, and a Rihanna or Beyonce tune comes on to the crappy house system. Over the background noise, what can you hear? Oftentimes, all that will be audible is a vocal, a hihat, maybe a little string line. The brightest elements, all pushed to the fore. If you're writing a vocal track, then the vocal will be what people latch onto, the bit that gets stuck in their brain, they'll be remembering the words. So you need to make it easy for them to pick out the vocal from the rest of the track. Err on the side of volume!

On a related note, you need to make sure the vocals are crisp and bright; plenty of top on there. This is less essential for backing vocals and harmonies, but in general you need to remember that your lead vocal will be jostling for space amongst the hihats and lead lines; so it needs to have plenty of high frequency content. In addition to vocals you've recorded yourself, I often find that acappellas downloaded from the internet can be recorded from vinyl, and lose some clarity in the process, so even with ready-recorded vocals you might need to add some top back on. Similarly, if you're working in strongly electronic fields, you'll need to compress the vocal fairly heavily. Of course, sometimes you want a natural feel to the track; but in this age of slamming basslines, searing leads, vocoders and overdubs, 'natural' tends to be restricted to Norah Jones records. You need the vocal not just to sit up front, but stay there, so get that compressor fired up. Fast attacks, medium release, hard knee, taking off anything up to 10 or even 15dB.

If you've recorded several takes, then it's good to layer them up to get a thicker, bigger sound. Pan a couple centrally, then have one to the left and one to the right for a really full atmosphere. But - and this is a big, tedious, important but - you need to make sure they're fully in time with each other. That means down to the level of individual words; even syllables - because if they're not, the result will just be a mess. Like having your drums slightly out of time, the impact will be lost. So this means you may need to go right in and edit your vocals word by word to line them up. It's a long and drawn out process, and possibly one of the most boring procedures in music production, but it's necessary.

Effects can be very useful on vocals, and used well can really bring a track to life. A good example is Magnetic Man's track 'I Need Air'. A fairly straightforward vocal, mainly on one note, is given a metallic texture in the verses with heavy use of a vocoder, and in the choruses with reverb and delay; while variety is provided with flangers, phasers, glitched edits, extreme reverb settings and so on. Without all this processing the vocal would be in danger of becoming dull; especially as it's a fairly wispy sounding recording with no backing tracks and few adlibs. Luckily, clever production techniques keep it engaging until the end.

Effects can also be used to 'rescue' a vocal somewhat - subtle use of an autotune can correct out of tune singers, chorus can beef up a thin sounding vocal track, and one of the most popular recovery tools is a good de-esser. Use these to cut out sections when your vocalist is overemphasising 'ss' sounds to create a harsh sibilance. A de-esser is essentially a frequency sensitive compressor; and getting good results is rather an inexact science.

The Sony Oxford de-esser comes highly recommended, but if you can't afford one of those then try your DAW's native option. Sibilance is usually around the 6-8kHz region, but you'll need to do some fine tuning. If it doesn't get the required result, then you can fall back on the long way - draw in some volume or EQ automation by hand. You can even try a standard compressor, set up to sidechain off a buss, where the buss contains just the vocal track tightly bandpassed around the offending frequency range. It's a convoluted solution, but if it gets the result you need, it's as valid as any other!

Production of vocals is a big subject to tackle in one article, but it's important to get to grips with if you're going to write the next chart smash. So don't wait around - dig out that microphone and get moving!

The Benefits of Referencing Your Mix

Time to think about referencing your tunes. Ever find that when you're getting your own tracks in the mix, or playing them out in a club, somehow they just don't sound quite right when you put them up against released tracks? Even though they sounded fine back at home? You're not alone! Let's dive in and look at how you can make sure you're getting the right balance...

When I say 'referencing', I'm going to be talking about two different things; there's listening to your track on different speakers and in different environments, and then there's comparing your track with others.

First though, before you even get to that stage, you should take a break. If you've been mixing down all evening, your ears will have gotten used to the track as it stands; anything you do will likely just make it sound 'wrong'. So go for a walk, listen to some completely different music, watch a bit of TV. Better still, leave it and come back tomorrow. Then, load a bounce of the track into iTunes or Winamp, and sit back. You'll be better able to appreciate what the track is actually doing if you can't see the mixer or the arrange window of your DAW; the brain has a funny way of rationalising everything, and it really helps just to listen to the file in a different program than usual.

Once you're happy with your mixdown so far, then you need to fire up some tunes that you think your track sounds similar to - or that you want it to sound similar to! Make sure you've got the volumes matched up so that they all sound the same level, and flick back and forth to compare the differences in the mix (you might find it's easiest to do this in your DAW so you can mute and unmute channels). There are some obvious things to listen out for, like the basic issues of a mixdown; is your snare much louder or quieter than another track? The vocals? On a more subtle note, you should listen out for the overall balance of the track. It could be that although everything sounds good individually, the higher frequency elements of your track are quieter, relative to the bass - which might mean they don't come through so well in a club. Or vice versa, of course.

If yours sounds somehow 'harsher' perhaps, but you can't identify which element is causing it, then it could be that you've been boosting high frequencies on several channels (again, even if they sound fine on their own), and would be well advised to go back in and tweak them.

Pay attention also to whether the other tracks use any cunning techniques with the arrangement - often you'll notice that a track may create space for a vocal by dropping out some lead lines or high frequency percussion; or will program the bassline so that it's not playing at the same time as the kick. This can be a useful way to avoid cluttering the mix, or avoid it sounding 'top heavy' for instance.

Many people find it helpful to use some kind of graphical frequency analyser when mixing down and referencing, and it can certainly help - if you look at one track which seems pretty flat, and yours has a strange spike at a certain frequency, then you may need to consider what is causing it. But equally, you don't necessarily have to go after every little peak in the spectrum - your track has to have some kind of sonic focus after all! You don't want to be mixing all the character out of your beats. And you should always try to trust your ears, rather than what you can see on the screen.

Once you're confident that you've got a balanced and comparable sound, you then need to go and take your new beat, and your reference tracks, and listen to them on other speakers. This is vitally important, as so far you're going to be working around the imperfections of your room and speaker set up. So there could be some issues you've not spotted yet.

If you can, try and listen on a small setup which doesn't have much bass, a bigger system which has plenty, and maybe in the car - car stereos can vary enormously. Some common things to look out for would be the low end - especially on the small system. Can you still hear the presence of the kick or sub on some tiny speakers? At the top end, does your lead or vocal still stand up clearly amongst the tinny rattle of the rest of the track? Is it the same with the released tracks? Similarly, on some boomy speakers, you want to make sure that the low end still has clarity, and doesn't drown out everything around it.

It's a bit of a long and often quite boring process, and one that will mean you get through plenty of blank CDs. But it's necessary if you want your tracks to hold up well against the best out there, so get a notepad and pen, and start listening closely. You may find your mixes start to improve quite quickly!