How to mix and how to set-up monitors? A Mackie guide on recording at home.
Mackie On Mixing
A good mix starts with a good performance and a good basic recording. While there are many things you can do while mixing to improve things that didn’t work out quite as well as expected, many musicians expect some kind of miracle cure that will magically compensate for bad tone, poor pitching and inaccurate timing. The reality is that the old saying, garbage in, garbage out still applies! The quality of vocal recordings made at home is often a problem where acoustic treatment has been neglected. Just hanging up a couple of duvets around the vocalist when recording makes all the difference.
The other important aspect that is often overlooked is the musical arrangement, not just what notes and chords are played and by what instrument but also details such as the actual chord inversions. To achieve a great mix then we need to start with a good performance of a well-arranged piece of music where the individual sounds are also chosen to work well together. Small flaws can be worked on and there’s still a lot we can do to adjust the sounds of the various instruments, but it helps to know the limitations of mixing and to recognise the stage at which mixing becomes mere salvage. Don’t worry too much about small amounts of spill between tracks though excessive spill can make it hard to achieve a clean sounding mix with a good balance.
Assuming you have captured what you need, much of what we tend to think of as mixing is actually preparation that needs to be done prior to the mix. It is a bit like painting a room where the hardest work is always stripping away the old paint, filling in cracks and preparing the surface for the new paint. If the preparation is done correctly the actual painting is the simplest part of the job — and so it is with mixing. The better you prepare the easier the mix will be.
Set a sensible monitoring level and try to stick to it apart from occasional checks to see how the mix sounds when played very loudly and very quietly. Use the sound level meter on your phone and aim for around 80 to 85dB. This will protect your hearing and allow you to work for longer without fatigue.
My approach is first to listen to the individual tracks in turn to identify any problems. If they can be fixed by editing or copying a good part from elsewhere that’s fine, otherwise they may need to be re-recorded. I’ll also crop away periods that are supposed to be silence as there are often background noises such as spill from other instruments, hum from guitar amplifiers or the rustling of lyric sheets. However, be careful not to get rid of all the breath sounds in the vocal track as a vocal can sound very unnatural without them. While gates can be useful to cutting down spill during pauses, manual editing can be more accurate in some situations. For example, I always mute the tom mic tracks between tom hits as the heads seem to resonate continually in sympathy with the other drums.
Next I’ll ‘comp’ any vocal or instrumental parts where the performer has recorded multiple versions so that I can use all the best parts to produce the best sounding tracks possible. Where vocal parts are layered, you can move parts around to tighten up any timing errors and also ensure that any layered breaths are lined up. Unused material is then muted and hidden or removed from the workspace.
If your DAW lets you change the colour of tracks on screen, adopting a colour coding system can help you navigate your mix. For example, you might make all the drum mic tracks one colour and all the keyboard parts another.
A mix that comprises a large number of individual tracks can be very difficult to manage so I try to subgroup common elements, such as all the mics on a drum kit, so that the whole drum kit level can be adjusted using a single fader once balanced. With a modern DAW you can do this using simple fader grouping but I still like to also route groups via their own bus so that I can add global processing to the group, such as overall compression or EQ, when necessary.
Another important step is to use low-cut filters on any tracks that are not intended to contribute to the bass part of the mix. In most cases that means everything except the kick drum, bass and perhaps the low toms. It is surprising how much unwanted low frequency energy can find its way into vocal or guitar tracks so put in an 18dB/octave low-cut filter and adjust the frequency as high as you can get it without affecting the part of the sound you want to keep. With some instruments, such as acoustic guitars used in a pop mix, you may want to set the filter frequency even higher to prevent the low end of the guitar from making the mix sound muddy. The key here is that it’s not about how tracks sound in isolation but how they sound when heard in the mix. You’ll be surprised how much cleaner your mix sound after cutting out those unwanted lows.
Following on from this previous point, it’s fine to apply any obvious EQ that you think is needed to individual tracks but be aware that you may need to change these settings when the whole mix is playing. Bass guitar is a case in point where what sounds impressive in isolation may become an indistinct boom when the other instruments are added.
When it comes to signal processing, and that includes EQ, always use it for a reason, not just because you feel you are expected to. Vocals often need some compression to make them sound more solid but be gentle with the EQ as it is very easy to make vocals sound harsh or unnatural. If a vocal isn’t cutting through, try a simple shelving high filter and add a few dBs of boost above 5 or 6kHz. If you boost much lower down the vocal can sound harsh and aggressive.
Those new to mixing often rely on plug-in presets but this can lead to problems when using compressors. A compressor works by reducing the gain when signals exceed a certain threshold level, but the preset designer doesn’t know how loud you recorded your track so the default threshold setting is likely to be incorrect. The solution is to call up a preset but then adjust the Threshold control so that the gain reduction meter shows between three and 10 dB of gain reduction on the signal peaks depending on the style of the vocals. The same is true when using compressor presets on instruments.
You’ll often get a better sounding result if you use your DAW’s level automation to smooth out any excessive level changes as this will make the compressor’s work much easier and it will avoid you having to apply excessive compression to keep the level under control. A little compression can add to the power of a sound but excessive compression can actually make a sound seem weaker.
Set up a reverb, such as a plate plug-in, plus a delay on two separate post-fader sends so that you can add them to your vocals as you mix. Modern vocal treatments almost always include a blend of reverb and delay where it is common to roll-off some top end from the delays to make them sit behind the vocal. Very clean and bright delays can sound too obvious. Listen to commercial records to see what they use — often the amount of delay and reverb added is less than you might imagine.
Different engineers approach balancing a mix in different ways, but unless you are very experienced, it might be useful to start with the bass and drums, then add in the vocals. These are key elements in modern pop music. The other instruments can then be slotted in as required starting with the guitar or keyboard part that carries the chordal structure of the song. Always leave plenty of headroom as the mix will get louder every time you bring in another track. Aim to leave around 12 to 18dB of headroom or safety margin on the individual tracks so that you don’t drive the main mix output into clipping — you can always bring up the overall level using plug-ins, such as compressors or limiters, in the master channel if you need to.
A mix needs perspective. When you are working on individual sounds, it is a temptation to try to make them all sound as big and as exciting as possible. However, in a good mix, some sounds such as vocals should appear to be at the front while others play a supporting role further back. If everything sounds big and bright your mix will sound congested with everything fighting for a place at the front. Keyboard pads, for example, can be tamed by removing both highs and lows using EQ and then mixing them in at a lower level. Effects such as reverb or chorus can also help push things further back in the mix.
Start your mix with all the sounds panned to the centre and try to achieve the best possible separation between instruments using balance and EQ. Only then pan elements to either side, making small level adjustments if necessary. Keep the bass, kick and lead vocals in the centre and then try to maintain a balance by panning, for example, a guitar slightly to one side and a keyboard to the other. Backing vocals may also be panned but this is where science becomes art so just do what sounds right. Check your stereo meters to ensure that your mix is always roughly symmetrical so that the load is shared evenly by the two speakers of a stereo system. Also press the Mono button from time to time to make sure that your mix still sounds acceptable in mono.
A useful tip that many professionals also employ is to listen to a mix from outside the studio leaving the door open. This allows you to focus on the general balance without having to worry about the details and you’ll hear balance issues much more easily than if you are sitting right in front of the speakers. If possible get somebody who is unfamiliar with the song to check if the lyrics are clear. You can’t do this yourself very easily as once you know the lyrics, your brain fills in the gaps and fools you into thinking they are clearer than they may actually be.
Take regular breaks and also play a few commercial records that are in a similar style to the mix you are working on to allow your ears to ‘recalibrate’. Also, when you think your mix is ready, leave it alone for a couple of hours, then come back and check it again. It is also worth double checking your mix on headphones as small flaws often show up more clearly. It also confirms that your mix will sound good for people listening on ear buds or headphones.
Finally, if your mix isn’t going to be mastered at another studio, don’t apply final compression and limiting to the whole mix to make it sound louder — that’s the mastering engineers job. Don’t worry that your mix doesn’t sound as loud as commercial records at this stage‚ just get the best sound that you can.
Monitoring with Mackie
If you want to know what your mix really sounds like you need a good pair of monitors. Hi-fi speakers are designed to make your music sound as good as possible — they flatter your music — but a good studio monitor is absolutely honest. A good mix will sound good but the flaws in a bad mix will be exposed.
There are many aspects to the design of a good studio monitor. Most monitors used in smaller studios are two-way systems, the majority of which are active meaning that each driver has its own amplifier and all the necessary electronics is built into the speaker cabinet.
Both the frequency and phase characteristics of the two drivers must be carefully matched, the crossover circuitry must be exactly tailored to the drivers and the amplifiers need to deliver adequate power with plenty of headroom yet still be designed to protect the drivers from excessively loud signals. The way the sound behaves as you move away from the main axis of the speaker is also important as this should be as even as possible so as to provide a wide ’sweet spot’ allowing you to move around a little when mixing.
But there’s more to it than simply buying good monitor speakers. The way that your monitors interface with your room is critical and in the case of the home studio, often neglected.
The way your monitors sound at the bass end of the audio spectrum is heavily influenced by the size and shape of your room and also by how you position the monitors within the room. The way they sound in the mid and high frequency range is more to do with what sound absorbing materials are in the room and on the walls. These might include carpets on the floor, curtains over the windows, soft furniture and acoustic foam panels.
Most home studios are set up in rectangular rooms where to get the most accurate bass response, it is vital that your monitors are aimed down the long axis of the room, not across it. A reasonably accurate bass response is important as if your speakers produce too much bass, you are likely to compensate by turning the bass down in the mix and vice versa. If you do this, when you come to play your recording on somebody else’s system the level of bass will be wrong.
Each parallel set of walls supports its set of own resonant frequencies or room modes and in the ideal studio these room modes will be fairly evenly distributed to produce a flat frequency response. The worst situation is a cube shaped room as all the room modes relating to the wall spacing, and to the floor to ceiling distance, will occur at the same frequencies resulting in a bass response that includes strong peaks and dips. The smaller the room the worse the problem, and you will also notice that if you sit close to the centre of a small square or cube shaped room, much of the bass disappears as there is strong cancellation at that point. Our ideal room has dimensions that are not equal or exact multiples of each other, though most home studio users have to make the best of whatever space they have available.
When working in small or unfortunately dimensioned rooms, smaller monitors work best — those with a bass driver no larger than six inches. This will limit the level of bass energy being fed into the room and so will produce a less confusing bass end. Avoid sitting midway between the front and rear wall when making critical mix decisions. If you need to check how the deep bass really sounds you can listen on headphones after getting the best possible balance on your monitor speakers.
Checking all your mixes on headphones as well as speakers is a good idea anyway as so many listeners now consume their music using earbuds or headphones. If you can get your mixes sounding good on both headphones and your monitor speakers you can be fairly confident that they are OK.
In larger rooms an eight inch bass driver may be appropriate for a two-way speaker. As a rule, avoid using subwoofers in smaller rooms as the results can be very unpredictable.
Your monitor speakers should be set up symmetrically about the centre axis of the room and ideally be at least 300mm away from walls or corners, especially if they have rear ports. Check the manual that came with your monitors as there may be rear panel switches that allow you to adjust the bass response to compensate for having to place the monitors closer to walls or corners than might be ideal. The tweeters should be aimed at an imaginary point just behind your head where your distance from the speakers is approximately the same as the distance between the speakers. You can tilt the speakers upwards to achieve the required angle if your monitors are positioned on a desk.
You have a choice of putting your monitors on good quality rigid stands or on your desk, but I would recommend that you do not put them directly on the surface of the desk as vibrations from the speaker cabinets may be transmitted into the desktop, which can have a negative impact on the sound quality. It also helps to raise the speakers above the desk surface, for example, on a raised shelf, to reduce reflections from the desk surface itself.
Speaker platforms made from dense foam rubber work well and they are even more effective if they have a heavy plate on top, as some commercial models do. Some also include separate wedge-shaped pieces to allow you to adjust the angle. A cheap foam platform can be improved by placing a heavy floor tile on top and then standing the speaker on that.
Avoid any obstructions between the speakers and your listening position, such as the edges of monitor screens.
Check your cables to ensure that the speakers are ‘in-phase’. The simplest way to do this is to use a cable tester to check that your cables are wired correctly. If the speakers are out of phase, the level of bass will drop and you will feel an uncomfortable sensation in your ears as you move your head from side to side while listening to music.
A good way to test the bass end of your system is to use a synthesiser or sampler to play a chromatic (semitone) scale of bass notes using a sine or triangle wave and then listen for any notes that sound excessively loud or quiet. In a perfect room the level of the notes should fall away gradually as the pitch is reduced. Most home studio rooms will show up some peaks and dips in the response but you can often improve the situation by moving the speakers slightly forwards or backwards. You may also find that moving both speakers to the left or right helps as this breaks the room symmetry slightly and helps smooth out the bass response. Commercial bass traps are available, most of which fit into the corners of the room, but in my experience they are of limited use in a small room and rarely provide a complete solution.
In extremely difficult rooms, active speaker equalisation systems, such as the IK Multimedia ARC system can improve the situation. Such systems measure the actual room response and then create a compensating EQ curve, often applied as a DAW plug-in, though some include a hardware equaliser box to put in your monitor chain.
Mid and high frequency problems are much easier to deal with where our main aim is to prevent strong sound reflections bouncing back to the listening position. Acoustic foam or mineral wool between 50 and 100 mm thick is very effective at absorbing sound from 250Hz upwards. Place a panel at either side of your listening position and another behind each of the speakers and you’ll hear a big improvement in the sound quality. A simple tip for hanging up foam panels without damaging the walls is to glue an old CD onto the back of the panel near the top, then hook the hole in the CD over a screw or nail fixed into the wall.
We often refer to the places that need acoustic panels as mirror points. That’s because if you were to place a mirror there, flat against the wall, while setting in your normal mixing position you’d be able to see a reflection of the monitor speakers. In rooms with low ceilings you might even want to put an absorber above you where the mirror point would be approximately over your knees.
In very small rooms it may also help to put acoustic panels on the wall behind you. In larger rooms, shelves of gear, books, CDs and so on also help break up reflections as do soft furnishing.
Your mixes will be more consistent if you try to mix all your music at around the same level. Somewhere around 80 to 85dB is comfortable and you can check this by running a sound level meter App on your phone. If you have your monitors set very loud all the time, your perception of balance changes and you may even damage your hearing. A good mix will still sound good at low volumes.
A trick many professionals use to double check their mixes is to stand outside the studio with the door open and listen to the balance from there. Often this will show up balance problems that weren’t obvious when you were sitting right in front of the speakers.
It also helps to have a selection of commercial reference tracks available for comparison purposes. playing these from time to time will help you retain a sense of perspective and will also help attune your ears to the way your monitors sound in your studio room.
