Side-chain Pumping Effect
Detailed tutorial on how to use side-chaining and filtering to create the famous Pumping effect.
The side-chain pump effect has been around since the birth of EDM and modern DAWs.
The effect is synonymous with drum beats and bass lines whereby the gain of the beat or bass line is over hyped to achieve a swelling and pumping effect. This is achieved through extreme ducking when using compression.
The pump effect is achieved by placing a compressor on the sound you want to pump, activating its side-chain and feeding a trigger to it. In most cases, and in EDM particularly, the kick drum channel is used as the trigger to activate the compressor. Each time the kick is played the compressor is activated and when the kick stops playing the compressor is deactivated. Whereas in traditional downward compressors the threshold is used to activate the gain reduction, in this scenario it is the kick that is used to trigger the compressor. The side-chain filter affords another level of control and can be used to specify which frequencies of the kick sound trigger the bass channel’s compressor. If a low threshold is used along with high ratio values the pump effect is emphasised even more.
Ghost triggering is a term we use to describe the use of a trigger that is not heard. In the kick/bass pump scenario we are listening to the kick as well as the bass at the same time. With ghost triggering the kick channel’s output routing is disabled in the DAW. This means we cannot hear the kick playing but it still acts as a trigger for the side-chain. A better solution is to make a copy of the kick channel and use the copy for triggering the compressor’s side-chain. That allows the original to be heard in the mix. Using ghost triggers is quite common nowadays as more and more producers are using them to shape a whole host of sounds.
The part of the circuitry that monitors the input level is known as the side-chain, and it controls that part of the circuitry that adjusts the gain of the main signal path. Side-chains have both internal and external filtering. You can use filtering to specify which frequencies you want to filter from the circuit. A good example of this is to hi pass filter kick drums at 100 Hz. This means that anything below 100 Hz is ignored when activating the compressor. This is a great way to avoid clutter in kick compression.
You can take the pump effect process a step further and use the side-chain filtering on the compressor to turn it into a frequency conscious trigger. In other words we can actually select a frequency range of the kick drum to trigger the compressor.
Parallel compression – New York compression
Most of my mix projects use parallel compression and for many sounds, not just the vocals which is the traditional sound of choice for parallel processing. To perform parallel processing you make a copy of the sound you want to process and process the copy and mix the original dry sound with the processed sound. Basically, you end up with two channels of audio: one processed and one unprocessed. The second method that can be used for parallel processing involves using the send feature of the DAW and sending the dry unprocessed sound to an effect channel. On the effect channel all manner of processes can be used and because the effects channel and dry channel play together you end up with parallel processing.
In the video I show you how to set up for parallel compression explaining each and every step of the process. I explore two types of compressors and how to use their side-chaining features to create the heavy pump effect. The side-chain’s filter is explained thoroughly and with using before and after audio examples.
Plugins used in this video:
Topics covered in this video are:
- Creating the Classic Side-chain Pump.
- Side-chain Filtering.
- Kick – Bass Frequency Considerations.
- Threshold and Ratio.
- Parallel Compression.
- Transient Control.
- Variable Response Topologies.
- Tips and Tricks.