The aural exciter is a great tool to use in the studio if you're looking to add some high-end clarity and sparkle to your music productions. It can help to add extra punch to a whole mix, or it can be used on individual tracks and instruments like vocals, drums, guitars, and bass.
Another studio device similar to the exciter is the audio enhancer. I'll take you through how they work and also how they're best used.
EQ is where you usually look first when you want to brighten an audio signal. But it can only boost or cut frequencies that are already present in the signal - it can't add anything extra that isn't already there.
Exciters actually add extra harmonic content to give the impression of a brighter, more present sound. They do this using a few key parts:
The input enters the exciter and splits into two - the dry signal and the wet signal. The dry signal passes straight through. The wet signal passes through the filter and the distortion, and is then added to the dry signal. The balance of dry and wet is set by the mix control.
The action of the filter means that only the top-end part of the signal has any distortion and extra harmonic content added to it, with the low and mid-range frequencies left alone to sound completely natural. Controlling the settings on the filter and the distortion changes the qualities of the sound leaving the exciter.
Enhancers act on both the high-end and the low-end. We perceive higher and lower frequencies as being slightly louder than mid-range frequencies, so turning these up can make the sound seem louder and more 'exciting', even though the overall sound is playing at the same volume level.
I don't want to go into too many technical details, but one of the things used to achieve this effect is something called dynamic EQ - basically where the audio is split in two and the lower bass frequencies are compressed, making the bass feel louder.
There's also the action of what's called sub-harmonic synthesis. Here the audio signal is analyzed and a new bass part is synthesized and added to the original signal, but at an octave lower. It's similar to the sub-oscillator control on a synthesizer.
It all began with the Aphex Systems Aural Exciter in the mid-1970s. Other hardware devices released over the years that have produced a similar sound are:
But there are now plenty of fantastic exciter plugins available. Some of the best are:
Here's a great little video of legendary engineer and producer Val Garay talking about the Aural Exciter from Aphex and about the emulation plugin from Waves:
As mentioned before, exciters and enhancers should be used sparingly in the studio - ideally when nothing else seems to be working. They're not to be used as a regular effect plugin.
Here are some general guidelines I've laid out for using them:
But remember, you don't have to follow all the rules, and rules are meant to be broken.