The EM Poll

After a Brief Delay

Sep 1, 2006 12:00 PM, By Jim Aikin

           

FIG. 1: This screen shot shows the rack in -Propellerhead Reason. The main signal paths for delay processing in Web Clip 5 are Aux Send 1 (not shown) to Delay 1 to Unison 1 to Scream 1 to Fast Delay and Delay 2 to Reverb 1 to Scream 2.

A delay line simply echoes its input at its output, and unless you take some extra steps, your listeners will soon tire of the effect. Rhythm-based delay lines, however, can add a vital element to electronic tracks. Sync the delay to the master clock, set it to a rhythmic value such as an eighth note, add a little feedback, and you've transformed a dry beat into a percolating phantasmagoria.

The Web Clips made for this column were created in Propellerhead Reason 3.0. Reason can patch devices together in user-defined signal paths, which makes developing complex multi-effect routings easier than it is with a conventional mixer (see Fig. 1). If you own Reason, you can download and experiment with a Reason song file for each of the examples presented here.

The Tone Zone

Begin by splitting the signal that you want to delay. Send one output of the splitter to the mixer dry, and send the other outputs to a couple of delay lines. The delays should be set to 100 percent wet, because you've handled the dry signal path manually. Set each delay to differing numbers of 16th notes to create a polyrhythm.

Next, patch a parametric equalizer between the output of each delay and the mixer. Set the two EQs so that each of them boosts a different narrow notch. In the mixer, pan the delay output channels left and right. The EQs will give each side of the stereo delay image its own tone color (see Web Clips 1 and 2).

Now patch a phaser after each EQ. Again, set the parameters of the two phasers differently, so as to give each side its own character.

Bad Bends

The order in which effects are patched is significant. If you use pitch bends on lead synth sounds, route the lead into a delay line set to a fairly short time with a bit of feedback. Send the output of the delay through a distortion effect.

Each time you bend a note, the distortion effect will receive several echoes of the bend, which will be at different pitches because they've been delayed by different amounts of time. When several notes at different pitches are distorted together, the distortion will add a rough edge to the tone. The result: a more expressive pitch bend. This patch can add subtle coloration or grinding distortion (see Web Clips 3 and 4).

Pick and Kick

Sending an entire drum loop through a delay line would likely produce an extremely busy texture. Instead, isolate a single sound within the loop and apply a delay to that sound. Digital audio sequencers allow you to isolate sounds in various ways. For example, you may be able to use a scissors tool to snip apart an audio waveform and drag a particular sound vertically to a different track without affecting its start time.

I loaded a REX file into Reason's NN-XT sampler and routed a few of the sample slices to a separate audio output. I chose a prominent backbeat slap sound in a hand-percussion loop for treatment and patched its output into the mixer, where two aux sends routed it to separate delay lines whose outputs were set to 100 percent wet.

The first of the delays, set to two 16th notes with some feedback, fed Reason's Unison (chorus) effect and a Scream distortion unit, giving each of the echoes a slightly different tone. Scream fed a third delay line that was set to a 4 ms delay and high feedback, which caused the delay line to ring. The slightly different tone at each input caused subtle variations in the waveform. This part of the patch works much like Karplus-Strong plucked-string synthesis.

I routed the second aux send to a delay of two 16th notes with no feedback followed by a Scream distortion unit, which turned the slap sound into a short noise burst. You can add a reverb with a short decay time between the delay line and the distortion to lengthen the noise burst (see Web Clips 5 and 6). Adding distortion to the output of a reverb destroys the natural character of the reverb, but it's good for horror-movie special effects like this one.

Jim Aikin is a cellist and a frequent EM contributor. He learned a few Reason programming tricks by editing Power Tools for Reason 3.0 (Backbeat Books, 2005), written by Kurt Kurasaki.