Hands on: Make the most of modulation effects in your music

Chorus
Chorus is created in a similar way to flanging. Again, an LFO is used to modulate the delay time. However, a chorus effect doesn’t feed any of the processed signal back into the effects loop. Instead, it generally uses longer delay times and this, combined with the lack of feedback, makes it a more subtle effect.

Chorus is generally used as a stereo effect. Stereo chorus is produced in much the same way as the mono version, except that the delay created by the LFO is varied between the right and left audio channels. Stereo chorus sounds more dramatic than mono chorus, as it is spread more widely across the stereo field.

Typical controls on a chorus plug-in include delay, depth/width, waveform/shape and speed or rate. The delay dial controls the amount of initial delay introduced by the chorus effect. Typical delay times range between 20ms and 30ms, and when a chorus is working with very short delay times, it will behave as a flanger. The depth or width setting controls how much the delay time changes over time.

On larger settings, the chorus will start to introduce a warble-type effect into the sound. The waveform or shape dial selects the waveform used to control how the delay changes over time, while the speed or rate settings control the speed at which the LFO waveform repeats.

Chorus is often used to create a more dream-like guitar sound. Over the years, it has been a staple of Goth music. The Cult used it heavily on tracks including She Sells Sanctuary and Rain, while other Goth bands such as the Sisters of Mercy and The Mission also used the effect with gusto.

It’s also often used on vocals and synth sounds as a quick and easy way of thickening them up. However, like reverb, chorus can have the effect of pushing the sound away, so you have to be careful not to use too much of it and end up sending the sound you are processing to the back of the mix.

Phasing
The final effect in the modulation family is phasing. It makes a pronounced filter sweep-type sound. It’s created in a very similar way to chorus and flanging, as it’s based around an LFO modulating the delay time of the affected signal. However, phasing uses much shorter delay times than either chorus or flanging, although it does use feedback in a similar way to flanging to increase the depth of its sweep.

A phaser typically has two main controls ­ feedback and rate. You use feedback to dictate how much of the processed signal is fed back into the effects loop. The more feedback, the more pronounced the effect. The rate setting controls the speed of the LFO, which in turn controls the speed of the modulation sweeps. Some phasers also have frequency and depth dials.

Phasing is a very popular effect and it’s commonly used on guitar parts in reggae tracks and guitar solos in rock music. It can be heard in prominence on tracks such as Itchycoo Park by the Small Faces.

Hopefully, this column will have given you not just a better grounding in how effects work, but also a bit of inspiration on how best to use them. The best advice we can give when adding effects to your tracks is that the old adage of ‘less is more’. Otherwise you may end up losing your track in a haze of sonic fireworks.

Pitch shifting
Although the pitch shifter effect has been superseded in modern audio sequencers by more complicated and realistic-sounding time-stretching algorithms, the effect is still used as a way of doubling up vocals or creating interesting special effects.

A traditional pitch shifter works by cutting the incoming audio into short pieces and either lengthening each of these sections when the pitch is being shifted downwards or shortening them when it’s shifted upwards. Usually some kind of cross-fading is used on each piece to make it less obvious the audio is being sliced.

Pitch shifters only really manage to sound ‘natural’ when they’re working on modest changes in pitch, not more than a couple of semi-tones. Pitch up too far and you’ll end up with a chipmunk-type sound; pitching down too much will result in a Dalek-style vocal.

Most pitch shifters always change pitch by the same number of semitones or cents, no matter which notes they’re dealing with. This means they can only really be used on settings for parallel fourths, fifths or octaves, as using other interval settings normally sounds ‘off’, because they don’t follow the usual music scales in use in western music.

However, pitch shifters are still useful for thickening up vocals. You can shift two copies of a vocal track up and down by four or five cents and mix them in with the main vocal to create a more layered sound. The limitations of pitch shifters can be also put to good use. For example, a common trick is to run a drumbeat through a pitch shifter with an extreme setting to give a very robotic, metallic sound.