How to make your own modulation effects

Delay isn’t just behind the overt effects you hear in a mix - it’s also responsible for far more subtle treatments that producers have been using heavily for many years. And it all started - as do most things in music production mythology - with those pesky Beatles.

Legend has it that the Fab Four had requested a method of double tracking vocals automatically. After Abbey Road engineer Ken Townsend came up with a solution - duplicating the vocal signal on tape and modulating one copy - the ‘flange’ effect was, supposedly, born, and used liberally on the appropriately titled Revolver.

Flanging isn’t too far removed from its sister effects of phasing and chorus. The three stem from the same simple process, and it’s easy to make your own with delay: set a short delay time, modulate it slightly, and make sure you’re running both dry and wet signals. Here are some recipes…

For more on taking your delay plugins to the next level, check out the July edition of Future Music.

1. Flanger

The simplest and most classic modulation effect, the humble flanger is created by delaying a signal, then modulating the delay time. Set your delay’s Dry/Wet to 50%, and make sure you keep the delay time quick - about 10 milliseconds to start off with. Now modulate the delay time with an LFO, at a rate below one second (ie, under 1Hz). Keep the delay amount low as well - you don’t really want the delay time to go over 20ms at its highest excursion.

Experiment with delay and modulation timing, and for a stronger effect and more ‘whoosh’, crank the delay’s feedback control up.

2. Chorus

Chorus is related to flanging - push the delay time up to (and over) 25 milliseconds to get into this territory. Crucially, you’ll notice that as you transition into chorusing, then crank the delay time up towards 35 milliseconds and on towards 50, you’ll get noticeable pitching effects. This is what gives this effect its name: it’s like a group of people or instruments together, all very slightly out of pitch.

Chorus is also a great widener of any signal. Again, experiment with feedback, modulation time and amount, and tweak the dry/wet mix if you want widening without pitch effects.

3. Stereo widener

There’s one more similar effect you can achieve with delay that’s not usually thought of in the same category as phasing, chorus and flanging: the Haas effect is more a scientific principle than a processor, but it has real and immediate implications.

If you take a stereo signal and delay just the left or right channel by one millisecond, the sound seems to come from the other side. It’s a very obvious effect to hear on headphones but it works on speakers too. To experiment further with the Haas effect, try delay times up to 30ms, feedback, and messing with your delay’s dry/wet mix amount.

4. Phaser

A traditional ‘phaser’ effect still works using delay, but actually uses an all-pass filter as its delay source. While you might immediately think that this would do sweet FA to the signal at hand, in reality the effect creates small delays with different timing for different frequencies (filters are built from capacitors, resistors and inductors, remember).

Unless you’d like to spend hours and hours setting up different delay lines to act differently depending on the frequency that passes through them, it’s better to stick with a dedicated phaser plugin if you want to achieve this particular effect!

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