From Home production

Problem Solving in Mixing and Mastering

For a lot of people just starting out with music production, mixing is often seen as an intractable part of the production process. A creative discipline that relates more to sound design than to the scientific discipline of mastering that follows.

However, in truth, although mixing and production can be combined by those that know what they’re doing, mixing (and mastering) are much more usefully viewed as separate stages. Less as sound design, more as problem solving.

What’s the problem?

Well, that all depends on the material of course. You could see it as the problem starting right at tracking. Given the right attention it’s completely possible to achieve the sound you want at the recording stage, although this very rarely happens.

With production comes the the arrangement and sound design that is very often confused with mixing. Mixing then becomes a case of corrective measures for audio problem – e.g. resonant frequencies, overly spiky guitar parts etc. as well as the overall problem of getting everything to sit well.

There is a tendency in home studios to mix as production happens, which is a good idea, after all, how the sounds fit together will change what sounds you put in.

But it’s a worthwhile exercise to take that as the rough mix, export all the stems and start from scratch to build the final mix. The psychological shift helps to concentrate on it less as the discipline of achieving “that” sound and more a case of fitting all the pieces together into a pleasing whole.

The problem solving approach

The up-shot of this psychological shift is that you’ll very often find that you spend less time chucking plug-ins at something in an effort to attain something ephemeral and take a more logical approach to it.

Every plug-in or processor in your chain, in both mixing and mastering, should be serving a distinct purpose. You don’t have to compress everything. Nor does everything necessarily require EQ’ing. It’s a case of using your ears to determine what the problem is e.g. ‘the kick is masked by the bass’, and then taking measures to correct it.

And yes, sometimes the problem actually is ‘the guitar doesn’t sound warm enough’.

The same approach is essential for mastering. There are a lot of myths regarding what has to be used in mastering – multiband compressors, brickwall limiters etc. But there are no hard and fast rules, only trends. It always depends on the material and the tools at hand.

The trick is knowing why you’re doing something. Use your ears, determine the problem and correct it. Mixing and mastering are both creative disciplines, but they are rooted in science.

Calibrating Your Ears – Why Referencing Matters

Objectivity

As anyone who’s banged their head against a troublesome mix for hours on end, only to be dismayed at the results the next day will know – staying objective in the studio can be difficult.

You only get a few seconds of objectivity when you listen to something before your brain simply gets used to whatever you’re hearing. So the trick is to listen carefully in these first few seconds, work on the problems you’ve identified and then re-calibrate your ears by listening to something else when you just can’t tell anymore.

Knowing your room

Just as important is knowing your room and your set up like the back of your hand. No room is acoustically perfect, no matter how well you treat it; and no speakers or headphones are completely transparent. Listening to a wide range of commercial material will alert you to the imperfections in your set up, allowing you to mentally account for them when you’re working.

For example, if your room has a bass resonance at 50Hz or so, when your kick drum is booming like a bomb, you’ll know that’s at least partly because it’s activating a room mode, and resist the urge to just cut everything in that region to tame it.

Setting benchmarks

In the same way, listening critically to a wide range of commercial material will give you a better idea of what lies within the acceptable range of variation, and what is just not up to scratch.

Many small studio owners fall victim to setting a mythical quality benchmark in their head that doesn’t actually exist. This can lead to obsessiveness over certain details that are actually fine to begin with. Sometimes it’s better to leave things sounding natural than process every inch of life out of them – try listening to a few Tom Waits recordings to see what I mean.

Make sure you listen in the appropriate format: CDs or CD quality files. MP3s and Spotify do sound different, and you don’t want to be emulating the degradation of lower quality files in your mixes.

Similarly, I have been known on occasion to despair at the lack of warmth and punch in what I’m working on only to realise I’ve been listening to too much vinyl lately…

A few tips…

  • Always start a mixing/mastering session by listening to reference material
  • Go back to it during the course of mixing to re-calibrate your ears
  • Use a range of reference material within a similar style of music
  • Use only CDs or CD quality files – MP3s, Spotify etc. all sound different
  • Import it into your DAW project so you’re using the same playback engine

A Beginner’s Guide to Compression – Part 3: Types of Compressor

If you’ve read the first two parts of this guide, you’ll now know what a compressor does and when you might use one. For part 3, we’re looking at different types of compressor to help you choose the right tool for the job.

Single band

Most compressors are single band (as opposed to multi band – see below). This means that they react to the dynamic content of the entire frequency spectrum equally.

For example, if you’re compressing a drum bus and you’ve got a huge bass drum with lots of sub on it, the compressor will kick in against that, reducing the level of everything else along with it (which can cause pumping.)

That’s why it’s often a good idea to do any corrective EQ you need before you hit the compressor, to make sure wayward rumbles don’t destroy the dynamics of what you’re compressing.

RMS

As well as being single band, most compressors will be RMS sensitive. Simply put, the RMS level is the average level of the material. So, rather than reacting against every single peak, an RMS compressor will smooth out the overall level.

To see the difference between RMS and peak, try download PSP Vintagemeter, load two versions, set one to VU and one to PPM. The former is showing the RMS values and the latter, peaks.

Peak

Peak compressors on the other hand, as you would expect, react to peaks. These are useful for ‘spiky’ or overly percussive material, and are often put in chain after using an RMS compressor, particularly on vocals. This way you can smooth out the overall level and use a peak compressor to tame anything still sticking out.

If using a peak compressor you would of course generally use shorter attack and release times than with an RMS sensitive compressor.

Peak compressors are less common, but many stock DAW plugins give you some control over how sensitive it is to RMS or peaks.

Limiters

Although many people think of limiters as being distinct from compressors, they are in fact simply fast acting, high ratio peak compressors.

They are most commonly used in mastering to squeeze every inch of level from a track without allowing any overs (unless we want to…)

Old style limiters still allow some peaks to go through, but the introduction of the brickwall limiter (starting with the famous Waves L2) allow us to keep squeezing until it hurts (literally in some cases).

Multiband

Multiband compressors can be any and all of the above; but they split the signal into separate frequency bands, allowing you to compress the bass, mids and treble separately (or more, or less, depending on the number of bands).

Multibands are again most often used in mastering where they’re useful for:

  • Targeting specific problem frequency areas (e.g. over-enthusiastic bass, too many sibilants)
  • Squeezing every ounce of level
  • Rebalancing a mix

Multiband compressors aren’t always the appropriate tool for the job, in fact, they’re usually not, but when they are they can be a real life saver. Be careful though – it’s very easy to destroy a sound with overuse of multiband, only use it if you really need to.

And the rest…

Beyond the types covered here, there are of course many different subsets and circuit types: feed-forward, feed-back, VCA, opto…the list is practically endless.

All of these behave differently and give a slightly different sound, but the best advice for these is just to try them and see. As long as you know you’re using a single band RMS compressor (for example) it will do the job you want it to, whether it’s opto or feed-forward etc. just means it will do it in a different way.