’side-chain compression’. ‘bass-ducking’. if you’ve been paying any attention to music production in the last few years, especially dance production, you know that these concepts play a huge role in the modern sound. virtually every dance track, and increasingly many rock and pop tracks, feature these techniques – so what are they, and how do you incorporate them into your productions using reason?
What is side-chaining?
side-chaining is a species of compression in which the amount of compression applied to an audio signal is determined by the level of a second audio signal. in other words, if signal A is being compressed using signal B as a side-chain input, signal A is compressed most when signal B is the loudest. this technique has many applications (for example, vocal ducking as used in radio, and de-essing) but the angle we’ll concern ourselves with here is side-chaining a signal in response to the kick drum.
What can i do with this technique?
modern house, trance, and electro tracks often feature a pad, vocal or effect which seems to pump or breathe with the rhythm – if you listen closely, you will notice their volume attenuating while the kick drum is ringing out. this effect is called ducking, and is achieved by effecting the pad or vocal sound using a compressor side-chained to the kick drum. likewise, this technique can be applied to the bass, which is called (appropriately) bass-ducking. bass-ducking deserves special consideration because, though it can be used to create the same pumping effect as with pads, it can be an indispensable tool for managing bass frequencies in songs in which phase interference between a powerful kick and a loud bass line presents a problem. whereas dance tracks of the early nineties predominantly solved the issue of bass frequency competition using an off-beat bass line, the more modern technique of bass-ducking can dynamically move the bass out of the way of the kick, giving you more freedom to write bass lines to suit your style, without having to worry about phase interference between these two bass-heavy elements.
ok, so how do i do it?
Sidechain Setup Front - Click to Enlarge
Implementing side-chain compression in reason is extremely straight-forward. you will need:
1. a redrum drum machine (loaded with a kit featuring a strong kick drum)
2. a spider audio merger and splitter
3. an m-class stereo compressor
4. a bass instrument
Side Chain Setup Back - Click to Enlarge
The trick of this technique is to split the audio output of your kick drum into two signals using the spider audio splitter, route one copy to your mixer and the other copy to the side-chain in on your m-class compressor. in order to achieve this:
1. switch to view the back of your rack by pressing tab. assuming your kick is loaded into channel one of your redrum, route the audio outs of redrum’s channel one to the audio-in on the ’split’ side of the spider unit.
2. wire one of the splitter outputs to the side-chain in on the compressor, the other to your main mixer (the kick signal sent to the compressor will not be audible, hence the need for a second copy).
3. finally, feed the bass instrument into the main audio input of your compressor so that ducking can be applied to it. (if you want to apply ducking to more than just the bass, add another spider or line mixer to mix down the signals to be ducked before routing the mixed output to the main input of the compressor.)
4. route the outputs of your redrum and m-class compressor to your mixer as usual and you have completed the setup.
you will want to edit the compressor settings to taste – a lower threshold and higher ratio value will make the ducking effect more pronounced.
This loop features a standard 4-to-the-floor beat with a heavy kick on every quarter note, a ringing ride cymbal, and a strong bass line. in the first example the compressor is disabled. you will notice that the kick drum sounds strong in the first four measures, but is almost completely obscured by the bass line once it comes in. this is because the kick and the bass share a similar frequency space and compete with one another for representation – this is obviously disastrous for your dance-floor aspirations.
This is exactly the same loop as before, but this time with the side-chain compressor enabled. if you listen carefully, you will notice the ride cymbal pumping with the kick drum over the first four measures; this is because it is being sent through the compressor along with the bass. (note that i am using another spider merger as a mixer to combine the bass, the ride cymbal, and the long snare to be compressed by the kick. put some thought into what you’d like to duck – your decisions can have both engineering and creative applications.) once the bass line kicks in, you should notice a more dramatic effect as the bass is ’sucked under’ the kick by the compressor, giving a slight pumping effect but more importantly allowing the kick drum to stand out and establish the rhythm without the bass line getting in the way.
conclusion
side-chain compression and bass-ducking are essential techniques for producing modern dance, pop, and rock music. thanks to the m-class compressor, these techniques are simple to implement in reason 4.0. once you’ve put together a good side-chain setup, try saving it as a default template document so that you’ll be ready to have clear, punchy kicks in all your future productions. Download the .rns file
This tutorial by dj.boddicker at http://boddicker.org/
Check it out