Tutorial: Dax Liniere

THE SPICE OF LIFE

Console emulation is not the only reason you should consider using saturation on channels. Sometimes our source material is cosmetically lacklustre and needs a dab of makeup, or perhaps we want to go the other direction and ugly it up a little.

For harsh or strident sounds — this could be cymbals, distorted guitars, vocals, brass, strings; almost anything, really — instead of reaching for an EQ to cut top-end, try a ‘warming’ saturator to round out the sound. A source that’s lacking bass or low-mids? Try a ‘fattening’ saturator like u-he Satin or FabFilter Saturn (the Warm Tape mode is a great place to start). Sometimes you’ll get a sound that’s too dull, so give it a bit of excitement with a saturator that generates strong upper harmonics. Maybe you have a loop or sample that’s boring and lifeless, if so, you could give it a bit of crunch. There are lots of saturators that can be used as a special effect. Try them on a small part you would usually tuck away in your mix. Like a sprinkle of chilli, it might just be the spice your mix needs. Plug-ins such as Voxengo’s Tube Amp, Togu Audio Line’s TAL-Tube and Camel Audio’s CamelCrusher are all very effective and also free.

To me, the best thing about ITB mixing is not the cost, but the flexibility. You may have already realised that different console emulation plug-ins could be used in different places in your mix. In the box, you are free from the restrictions that working in the analogue domain imposes. You’re free to use the forward midrange sound of an API for your drums, the fatness of a Neve for your bass and the wide low-mids of a Trident for your guitars. Even the use of different tape types and speeds can be decided on a per-track basis. You cannot practically do this when mixing in the analogue domain.

Better still, you can choose to have no colouration at all on a sensitive source like vocals. This, ladies and gentlemen, is the single best thing about mixing In-The-Box: wherever you don’t want colouration, you don’t need to have it. While we can simulate the non-linearities of the analogue world in digital, analogue cannot pass a signal from one end of the chain to the other without imparting colouration and distortion. In short, In-The-Box can deliver the Outside-The-Box sound, but OTB cannot deliver the ITB sound.

MORE WIDTH

In Issue 96, I wrote about width in analogue mixes and how crosstalk affects the stereo image. There are many things at play inside any analogue circuit that may affect the perception of width, making it either wider or narrower. An analogue console contains thousands of electronic components: resistors, capacitors, inductors, transistors and integrated circuits. Although each of these has a specified value within the circuit design, the actual value may vary within a few percent, this is called the component’s tolerance. These minute differences between components accumulate throughout the signal path, resulting in subtle differences in frequency response, noise (amount and spectrum), dynamics and saturation. It’s been suggested that the noise present at a console’s output is perceived by the brain as an increase in reverb and because this noise is left-right uncorrelated (i.e., different on both sides) the ‘additional reverb’ appears wide. All of these left-right differences can contribute to the perception of subtle widening.

The important thing to remember is that this widening is uncontrolled. Your stereo field (including your centre image) will always be slightly spread by an amount that varies with temperature and age. In the box, you can choose to apply plug-ins that simulate this behaviour only on the channels you want to affect.

EQUALISERS

We’ve looked at the console input stage, its output bus and the tape it records to, but sitting in between all that is the humble equaliser, another great source of colouration. Every EQ circuit design has different properties that reflect the philosophies of its designer. Some are clean, some add character, some are surgical, and some ‘musical’. Whether Pultec, Neve, API, Helios or Trident, supplementing console EQs with outboard is a long-standing practice which can avail a broad palette of sound-shaping tools. New toys are fun, but learning the tools you have, especially your ears, is most important. The best advice I could give any engineer about equalisation is to practice ear training. The faster and more easily you can identify frequencies, the more efficient and better your work will become. This is especially true for live sound, where reaction time can be the difference between smiling and frowning musicians. It will also help you to identify how other mixes are constructed and how sounds are placed, which is a great way to learn and improve your own mixing.

There are many ear-training apps available based around one-third-octave bands. Quiztones is one that’s available for iOS and Android and costs less than a beer.

Now what are you going to do with these newly learned skills? Put them to good use with these great EQ plug-ins!

Tutorial: Dax Liniere

LEAVING THE RIGHT COMPRESSION

Once you’ve decided on your colour, it’s time to look at dynamics. Most modern music makes extensive use of compression, both on the track level and the master bus. The SSL 4000 series consoles are rare pieces of gear we can label as truly iconic. Countless records have been mixed on this series and it’s helped define a modern sonic template for rock, pop and other punchy genres. All of which has a lot to do with the sound of its famous bus compressor.

When using a compressor on your master bus, start with a gentle ratio of 2:1. If you find you’re getting too much overshoot, this is probably a good sign that the tracks feeding the compressor are too dynamic and you don’t have quite enough compression at the track level. An attack of 10ms is a good starting place and should allow enough transients through while still controlling the dynamics.

When I mix, my bus compressor’s needle usually sits around 2dBGR (decibels of gain reduction), sometimes hitting 4dBGR for short periods.

Bear in mind there is never one setting for all songs. Every song is different and should be treated that way. And how you set your processors defines your sound so don’t be afraid to experiment.

I wouldn’t recommend new mix engineers use a bus compressor until they’ve mastered the art of mixing without. It’s very easy to get into a tail-chasing loop; turn up one track to get it above the rest, then turn up another track, and another… soon enough your gain reduction meter could be sitting at -20dB.

It’s not necessary to have a master bus compressor engaged if you’re shaping sounds during the early stages of a mix. But you should enable it whenever in the process you’re ready to start balancing your mix. This is especially important when you’re working on the loudest parts of a song since this is where the compressor will be pushed the hardest and you need to know how it will handle that; will the crescendo of the song be crushed at the master bus?

Engaging your master bus compressor too early can be detrimental. Say you’re adjusting the compression on a particular track. If your master bus compressor is also compressing, then you’ll be unable to judge the true effect of the track’s compressor.

Speaking of things to avoid, I strongly advise against using limiters on the master bus during mixing. For the inexperienced, they have too much potential to do damage and the tail-chasing I mentioned above usually results in more severe sonic mangling than with a compressor. If you do use them for ‘safety reasons’, it is imperative that you ensure the levels entering the limiter stay below its threshold.

IS THIS MASTERING?

So is all this master bus processing the same as sending your tracks off to a mastering house? In short, no. There are unique roles a good mastering engineer plays in the production of your projects, things you probably can’t do yourself. Here are some reasons:

1. It’s generally accepted that you shouldn’t master in the same room you mix. The reason is any flaws in frequency or transient response in your listening environment (the combination of your speakers and room) will only be compounded if you attempt to master there. You can’t fix what you can’t hear, and mastering in a different space may allow you to hear problems that need correcting.
2. Mastering engineers spend much time and money establishing a superior monitoring system and listening environment. It’s not just big, expensive speakers, but also carefully planned acoustic treatments to create an accurate, full bandwidth listening room, and the ear-training that comes with years of acute listening and experience with multiple musical genres. Having on your team an experienced listener who is also an experienced communicator can help you derive the best possible outcome.
3. The over-arching role the mastering engineer plays is that of quality control. It’s their responsibility to ensure the final product is free from technical flaws. Mastering is the final chance to catch anything that may have been missed earlier in the process and, as such, it is an exercise in risk management and quality assurance.

Tutorial: Dax Liniere

WIDTH — A LEAKY DEFINITION

‘Width’ is even easier to define and can be used to explain away another one of the myths surrounding analogue consoles.

Analogue equipment has an affliction called crosstalk, which is where signal from one signal path ‘leaks’ into adjacent signal paths. This can occur when one or more tracks on a printed circuit board are in close proximity. In a DAW or digital mixer, crosstalk cannot naturally occur since each ‘signal path’ is a separate stream of data.

In a stereo mixing scenario, a mono sound that’s panned centre is obviously not coming out of the centre, since there is no centre speaker. It’s created in what we call the phantom centre. This is simply the psycho-acoustic phenomenon where an identical sound of the same volume and phase arrives at both ears at the same time. This gives the impression that it originates from directly in front of us.

When you pan a sound hard left, none of that signal is routed to the right channel and vice-versa. If you adjust a pan control away from hard left, you are directing some of that sound to the right channel. The closer to centre pan, the less volume difference there is between left and right channels, until you reach the centre position where both channels receive the same signal and it appears to originate from between the stereo speakers.

If you have a pair of non-identical sounds, panning them less than hard left and right will result in the soundfield becoming narrower. Crosstalk obviously affects width, therefore claiming a mix done on an analogue console intrinsically has more ‘width’ than an ITB mix is complete nonsense.

PUNCH — CAPACITY FOR ATTACK

While the terms ‘depth’ and ‘width’ are either being used incorrectly, or relate more closely to the skill of the person who can afford to use a large-format console, we still have to address the term ‘punch’. A ‘punchy’ sound can be described as having a strong attack (without being too sharp or biting) and where the attack of the signal is quite even, despite fluctuations in input signal.

There are many parts of an analogue console where distortions and colourations are induced on the signals passing through them. The most significant are transformers and other reactive components such as capacitors.

A transformer uses two coils of wire — a ‘primary’ and a ‘secondary’ — wound in close proximity around a metal core. There is no electrical contact between the individual coils or the metal core — the signal is induced into the secondary coil by the primary coil via electromagnetism. When the coils are driven too hard, i.e. by a large signal, the transformer will saturate or ‘soft-clip’ and introduce harmonic distortion to the signal. In the right quantities, this can be quite pleasing and musical, but as with anything, it can be easily overdone.

Being a magnetic device, the sound of the saturation is somewhat like the sound of analogue tape when it is pushed too hard. Different types of transformers have different saturation characteristics, mostly depending on the type of metal used in the core (to my ear, the cleanest is nickel, followed by iron, with steel core being the most coloured).

By their nature, low frequencies have more energy than high frequencies. It’s the kind of energy found in a kick drum signal that can saturate a transformer, causing excitation of low frequencies which produces easily audible upper harmonics.

Capacitors are often used in consoles to ‘decouple’ one circuit from another (eg. the mic preamp from the EQ). In many circuit designs the audio output signal contains a portion of the DC power supply voltage and it is not desirable to pass that on to the next circuit. Capacitors are used to make that bridge, passing the audio signal voltage but blocking the power supply voltage. In other words, decoupling the DC component of the signal or removing DC bias.

Capacitors are reactive components, meaning their behaviour changes with frequency. They are capable of altering a signal’s phase and frequency response, and can therefore impart their own subtle tonal colouration on the signal. Some analogue audio circuits use many decoupling capacitors in each channel strip, collectively contributing significantly to the overall sound of the console. (Transformers are also reactive devices and can alter a signal’s phase and frequency response, in addition to introducing saturation.)

The important thing to remember is that every time your signal passes through another circuit stage, you introduce another layer of distortion and/or colouration.

It’s this short-duration saturation of transients that increases the apparent ‘punch’ of a sound. Since this soft clipping is due to the input level reaching a finite ceiling, the resulting harmonics are produced at a consistent level.

BANDWIDTH: FLAT TO THE LIMIT

Another difference between OTB and ITB is bandwidth. While console manufacturers and DAW developers all strive to give their products the widest and flattest frequency response, in reality, the limitations of physics come into play in both worlds. Any digitally sampled signal has an upper limit on the frequencies that can be captured and reproduced. Harry Nyquist, in his sampling theorem, states this is half the sample rate, which for people working at 44.1k, gives a limit of just over 22kHz. Analogue consoles, on the other hand, extend to at least 30kHz. Rupert Neve believes consoles should be ‘clean’ up to 100kHz. Whether those ‘inaudible’ high frequencies are significant is an entirely different argument, but the only way to match this ITB is to run your system at greater than a 192k sampling rate.

On the other end of the spectrum, a properly-designed DAW has a frequency range that extends flat down to 0Hz. Compared to even the highest spec’d analogue consoles which roll off around 15-20Hz, there’s a fair bit more going on down there, not to mention the phase shift caused by that roll-off.

Though most DAW developers have accomplished what console designers set out to achieve, is that actually useful? Unless you’re using your DAW for scientific purposes, the answer is a resounding no.

AT THE CROSSROADS

Of course, sonic differences aren’t the only thing setting OTB and ITB apart: ergonomics and workflow play a large part in the experience of mixing a song. A hardware console is undoubtedly a more physical, more tactile way to mix. Even a control surface can’t offer the same level of physicality due to the reduced number of controls. I quite enjoy balancing a mix spread across console faders; it’s a great way to experiment with different combinations far quicker than is possible with a mouse alone.

But I’ve observed something interesting. For most ‘A-list’ engineers if the balance of a mix doesn’t feel right… swish, all the faders go back down and they’ll try a different tack.

But when mixing ITB, people seem less likely to start over from scratch, which is odd, because it’s even easier to achieve in a DAW. Just save a copy and try something completely different, if you’re not happy with the road you ventured down, a few clicks and you’re back at the crossroads.

Another difference from ‘the old ways’ is that now we have a computer screen to steal our attention. Whereas before, there were no visual cues to pre-empt, and less distractions from our primary task of listening. Thankfully, there are solutions. Basically, what we want to do is blank our computer monitors quickly and easily when we’re doing our critical listening [which some would argue is all the time — Ed]. On a PC, this is easily achieved by setting your screensaver to a blank screen. Then use a free program like ShutdownTray to trigger the screensaver with a quick keyboard shortcut. Mac users have it even easier with Hot Corners. Just pick your corner and set it to ‘Put Display To Sleep’.

THE CHOICE IS YOURS

Working in the analogue domain imposes other limitations, but often, those limitations can be used to our advantage. OTB, the number of mixable tracks is limited by the available console inputs and D/A converter channels, and the amount of outboard processors is limited by budget and available space. ITB, our track and processor count is only limited by the computer’s available system resources. Buy a plug-in and you can use as many instances as your system will bear.

When you’re working on a production ITB, don’t leave all of your decisions until the mix phase. While it seems logical that no-one would want to paint themselves into a corner, leaving options open can be an enabler of indecisiveness. Limitations can challenge you and make you grow. They can force you to think in a different way in order to solve a problem to reach your end goal. Quite simply, practice the act of committing to decisions early in the production process. Sure you might make some mistakes, but without mistakes, how can we grow?

ANALOGUE TIME-SOAK

As mastering engineer Sean Diggins says, “We are in a time-based industry and analogue is a time-soak.”

OTB mixdowns are restricted to realtime; stems are more difficult to produce; and recalls take time and leave room for error. The sound of hardware can change due to heat, power and atmospheric variations, plus deterioration through ageing. While reliability issues can be mostly mitigated through meticulous maintenance, this requires money, time and expertise. Every mixdown, revision, stem and repair takes time. Every extra ‘instance’ of outboard gear costs money, compared to a plug-in which is bought once and inserted many times. To be fair, plug-ins can also break compatibility with system upgrades or lose support completely (as in the case of the fantastic Voxengo Marquis compressor). You also never have to worry about copy protection with outboard gear.

Are the perks of analogue mixing worth the drawbacks, or vice versa? Ultimately, that’s for you to decide. To me, there is a clear-cut winner, and that is ITB. It has everything going for it — instant recall, full automation, ‘unlimited’ processors (restricted only by your CPU power), no noise and minimal maintenance, editing capabilities that open up new sonic and production possibilities, faster-than-realtime bounces and a great sound that can be relied upon to give the same results every time. But remember, to get the most in the box, we must think outside it.