Stereo effects with modulation
Using modulation for widening
Most modulation effects operate in stereo and they do this by offsetting the left and right channels, which effectively creates two different signals on either side of the stereo field. This is usually done by differing the LFO position for left and right, meaning that the rate of modulation will run differently for either side. This often sounds impressively wide and lush, but at the expense of phase coherence between left and right, meaning that your stereo signal’s timbre may change dramatically when the track is played back in mono. Be sure to test for mono compatibility, and rein things in if the phase cancellation is too destructive.
Although we tend to use modulation to provide centred signals (ie, a mono guitar part) with width, don’t be afraid to go old-school and instead use these effects in mono. A straight-up mono chorus effect on synths can give a distinctive ‘fluffy’ timbre that sounds completely different to its stereo equivalent.
A touch of chorus can be the perfect stereo widener for vocals or synths. Keep the effect’s rate to a slow speed for gentle ‘drifting’, or ramp up rate amount for a more ‘bubbling’ effect. Feedback values should be kept low for subtlety. By mixing in your modulation effect via an auxiliary return, you’ll have greater flexibility over your stereo width. Use a stereo controller plugin or mid/side processor last in the aux chain in order to customise the signal’s width to your choosing. Another widening trick involves panning your dry signal to one side of the stereo field, and your modulated signal to the opposing side. You don’t have to keep their pan offset values equal, either: try centring the dry sound, then push your effect signal out further.