Last month, we took a deeper look at waveshaping and overdrive. This month, we’ll look at alternative uses for bit-crushing. Ableton Live refers to this effect as “Redux,” and Propellerhead Reason includes it in its Scream device as the “Digital” mode. The bit-crushing sound is based on down-sampling. By reducing the sample rate of digital audio—without the usual filtering of frequencies that are greater than half the sampling rate—the result is aliasing: grungy artifacts of the sample rate being too low to accommodate the audio’s upper frequency range. Normally, you don’t want it. Here, we’ll dare to be different. Scroll to the bottom of this page for audio examples.
Crunchy Top Loops
Sometimes hi-hats and top loop material can have too much high-end sizzle. EQ is a common way to tame this, but bitcrushing can accomplish a similar thing while adding a bit more upper-mid crunch. The secret is to use just a tiny bit. Here’s Apple Logic’s processor in action.
Example 2: Tuned Aliasing
The aliasing tones created by down-sampling can often be tuned to the overall key of your mix. So, analyze the dominant pitches in your mix and tune your effect to reinforce the musicality of your production. For rhythmic loops, you can transform the part entirely by adding a gate after the bit-crusher, then adjusting the threshold until a tighter rhythm is created.
Video Game Explosions
Some bit-crushers, such as Ableton Live’s Redux, include a “hard” mode for downsampling. This is often too intense for a mainstream mix, but it excels at vintage video game explosion effects. Just run a noise burst into Redux and twiddle until you get that “Missile Command” sound. For Reason users, Thor’s noise oscillator has a sample-and-hold mode that does this trick quite nicely.
Example 4: Rises and Falls
In previous columns, we’ve covered the ups and downs of creating rises and falls. For a tougher version of this production trick, try automating the down-sampling value of your bit-crusher. Higher values create lower pitches, and vice versa, so as always, use your ears as you automate the effect.
- Audio Examples
- Example 1: Crunchy Top Loops
- Example 2: Tuned Aliasing
- Example 3: Video Game Explosions
- Example 4: Rises and Falls