Freelance recordist Alan Hill talks about why it is that we're all obsessed with seemingly expensive analogue gear or boutique guitar amplifiers.
Why do we pay big money in pursuit of that illusive sound or tone?
I think it's fair say we all agree that analogue gear – be it an amp, compressor, or an EQ unit – is considered to be warm, musical, and any other hyperbole you choose to use. But what does that actually mean in real terms?
Before we delve into that let's look at the source, what we're actually recording.
It seems obvious to state – but a singer, drummer, or a saxophonist each sound different from each other – even when playing the same note. The differential is refereed to as the timbre or tone of an instrument. In simple terms it's what makes one thing sound different from another.
For example when a guitar plays an A note, what is generated is a complex waveform. A complex waveform is made up of multiple sine waves, which when heard together make up the instrument’s unique timbre.
If we breakdown this waveform further we realise it is made up of two component parts, the first being a fundamental frequency. Put simply, a fundamental frequency is the note the instrument is playing. It's important to remember musical notes can be expressed as frequencies as well as notes. A good exercise here is to pull up a tone generator in your DAW and dial in a sine wave at 110Hz. What you’re hearing is an A note as a perfect sine wave. Such perfection isn't often heard in the real world, as it's rare a waveform will be generated without some form of harmonic coloration.
Harmonic coloration makes up the rest of our complex waveform, if you will the jagged bits on a waveform, and these make the difference between a saxophone playing A1 or a guitar. They are secondary sine waves, which are whole multiple numbers of the fundamental frequency. Once again using our A (110Hz), the secondary harmonics would be 220Hz (A), 330HZ (E), 440Hz (A), and 550Hz (C#) etc. Now whilst this relationship remains the same regardless of the instrument the amplitude does not, which results in giving an instrument its unique character.
Below are some examples, but when you next load up your DAW, plug in an instrument, pull up a frequency analyser, and pluck a note. When you know what you’re looking for you can see the fundamental and the resulting harmonics quite clearly.
110 Hz tone
OK so bank that…
When you’re amplifying an electrical signal, in an ideal world you want the output to be exactly the same as the input, just amplified. However this is never the case, electronics add harmonics due to the nature of the components. These harmonics are a distortion of the input signal and are called… wait for it… harmonic distortion.
If we took our friend the 110Hz sine wave and ran it through let’s say a Neve desk, what would come out the other end would be the 110Hz sine wave and other peaks, which would be our harmonic distortion.
In the type of work I primarily do harmonic distortion is very undesirable, my primary role is to gather sound as cleanly as possible. So the type of gear I use has a low total harmonic distortion (%THD). People would talk about this type of pre amp being natural sounding or neutral.
A guitar amp on the other hand is the other end of this and would have a high THD. 'Colouring' the sound in a big way. As soon as you bring EQ in the equation – which has different set points and Q slopes on each amp – you start to understand how and why each amp can sound radically different.
Coupling that with the idea each instrument produces differing levels of natural harmonics, you start to understand why people are so particular about the equipment and instruments they work with.
Now I'm not for one minute suggesting that expensive is good in that regard. If the amp/guitar was a few hundred pounds but it produces a wonderful or sometimes not so wonderful sound then so be it, and the fact that it's cheap is much better for everybody.
When you think about it, this is happening at all levels of a recording stage: microphones into pre amps, pre-amps to compressors etc. While these things may be very subtle when several of these elements are bought together, it's easy to understand why people are so fussy about gear as all the little harmonic ingredients end up make something sound really special.
Alan Hill has worked as a professional sound recordist since 2001 and over the course of his career has filmed on boats, in helicopters, cars, up mountains, in deserts, down caves, and occasionally just in London. He also plays guitar, bass, and writes music for The Lovers.