Redlining, turning it up to eleven, cranking it up. It all sounds very cool, very rock and roll. But does it actually sound any good? Let's take a look at the details of going into the red and what it can mean for your tunes...Back in the day, this was a pretty straightforward equation. When you're working with hardware, if you go into the red, it's simple - things will distort. This wasn't always a bad thing, however; the classic example of distortion sounding good is the electric guitar. It fizzes, squeals, and has zero dynamic range, but still sounds great.
People also still talk about the "warmth" from overdriving a piece of valve kit, and there are any number of plugins available now that claim to emulate the sound of overdriving a channel on a classic SSL desk or tape saturation. But once we get into this world of digital emulation, it starts getting a lot less clear.
The buzzwords here are "digital clipping" and you'll no doubt have heard about how terrible it is. Generally, it is indeed terrible. Cold, harsh, it doesn't really add anything to your tracks, and it's the sound of what happens when a digital environment can't cope any more and goes over zero. Fortunately, most DAWs are so well coded these days, and now we're up to 64-bit programs, they can take a lot in their stride. What does this mean? You might have heard about floating point calculations and whatnot; the upshot is that you can have an individual channel going way into the red and it still won't clip - until it gets to the master output, of course. Problem solved? Unfortunately not.
What a modern DAW can't compensate for is what you're doing with the plugins. While you might have your audio channel peaking above zero and sounding OK, if you then feed that signal into an EQ, compressor, or other processor, it may not be able to handle the amplitude, and will clip, distort, and generally mess up your sound. Although it might be a plugin that's designed to emulate classic hardware, you can bet that the input stage of it doesn't work in quite the same way; after all, a 1970's valve EQ never had to deal with a digital signal at +11dB. So it's important to make sure that the plugin receives its signal at a sensible level, and equally, that the output gain is set appropriately so that the next plugin isn't sabotaged either.It's increasingly common to find mixdowns where the drums or bass sound unpleasant and squashed, but the problem isn't in the processing as such, but in the links where one plugin feeds into another. If you have a chain of plugins, and one in the middle is outputting a huge signal, it will just overload the next plugin. And it might not be visible once you get to the end of the chain, as a third plugin may have reduced the volume so that you're back below zero. The result, however, will be a mixdown that looks right - your EQ and compression settings may be perfect - but sounds bad, as one of the plugins is wiping out all your transients.
Fortunately, as well as a good DAW being able to handle large signals these days, they also have enough bit depth to handle smaller signals without adding noise. So you can afford to have everything turned down pretty quiet, especially your plugin outputs; it won't hurt your mix but it might save it! It's always better to have things arriving at your master output on the quiet side; you can turn it up at the end. Easier than going back through the mix to figure out what's causing (or killing) all these peaks.
As mentioned earlier though; hardware? Well, that's another matter entirely. If you have a keyboard it's always worth trying to run it hard through your line mixer, pre-amp or whatever else you have lying around, just to see what happens - but again, as we're talking about going into a DAW here, make sure it's back below zero before it hits your soundcard! Hardware distortion can sound very different; it will add harmonics, it may cut certain frequencies at the top or bottom, it can sound great, or (often) crappy. Sometimes crappy is what you want for a given sound, but in general you'll find that you need to try everything in your studio to find the one item that sounds cool being overdriven. When you find it, it's useful for lead sounds to give a ripping presence at the top end; overdriving a bass sound (especially subs) will introduce harmonics that make the sound come through more clearly in the mix; crunching those drums a bit may give you a compression sound that's a bit more rugged than an actual compresssor would.This topic is one that can get very technical, very quickly; but that's not what we're all about here. So in summary, the best practice is to make sure that within your DAW, everything is running at nice low levels - not only will this avoid any plugin related distortion, but it will also make your mixdowns much easier; so you're not having to turn down one thing to make room for something else. Do this, and you'll suddenly find that worries about clipping or distortion are a thing of the past - and overdriving only happens when you really want it to!
