In this free four-part free video tutorial series, brought to you with the kind support from our friends at Waves, we take a look at four plug-ins you can use to augment stereo content in a mix. Two of which are capable of producing pseudo-stereo from mono content.

Often referred to as stereoisers, stereo imager plug-ins use psychoacoustic principles to enhance audio spatially. Some of these plug-ins can transform mono (single channel) audio tracks into wide and luscious sounding stereo tracks. Others can augment and intensify the stereo effects in existing stereo content. Other typical applications include:

• Producing natural-sounding stereo acoustic guitars from mono tracks recorded with a single microphone

• Creating deep sounding synth parts

• Sitting a single background vocal behind and around mono lead vocal parts

• Producing width in mono effect tracks such as delay

In this series of videos tutorials, we demonstrate the effects of each of these four plug-ins to enable you to learn and appreciate what each of them are capable of in a mix.

Augment Or Enhance The Image Of Stereo Tracks

The following two plug-ins are worth considering if you need to enhance the stereo image of stereo tracks. Typically applications include:

• Gently widening a master

• Pushing the soundstage out into the corner of your monitors to make space for centred mono tracks

1 - Waves S1 Imager

Waves S1 Imager is one of the simplest plug-ins in this series. The main control you will find yourself reaching for time and again is Width which simply widens or narrows stereo tracks. The half-circle shape and soundstage graphic in the middle display is the stereo vector display, this gives us a general sense of what’s going on in S1.

Back to width. Set values below 1 to narrow or even mono the soundstage. For width effects greater than 1, the sound stage is widened, with sounds at the two edges of the stereo stage being moved beyond the loudspeakers. The plug-in is in essence bypassed with values set at 1. 

Asymmetry comes into play after you’ve made a width adjustment. This doesn’t touch central in-phase mono sounds, instead, it adjusts relative levels for left and right sounds. In short, it keeps centre sounds centred, useful if you want to augment the relative levels at the two sides of a stereo stage without pushing a mix off-centre. Though you can, if you choose to move the centre by adjusting for the Rotation fader.

The Waves Stereo Imager also has an MS encoder so you can feed it with the output of an MS microphone setup.

2 - Center

We’ve already looked at Waves S1 Imager, an excellent tool for pushing the limits of width in stereo content while retaining centre information. In this section, we’re going to look at Center, which can also be used to dial in a sense of width, but this has a special trick up its sleeve. It separates phantom centre content from left/right side content, to enable users to attenuate mono centred material, such as a lead vocal in a mix.

The two main fader controls Centre and Sides are used to control the level and balance of the centre and side information. For dealing in a sense of width, try playing around with the top set of controls Low and High-frequency balance and transient shaper Punch.

Creating A Sense Of Stereo From Mono Tracks

The following two plug-ins are well worth trying for yourself if you have mono tracks that you feel need some stereo fairy dust. Typical applications for these are:

• Transforming a mono acoustic guitar recording into a stereo-like track

• Widening mono tape delay effects

3 - Doubler

Doubler takes incoming audio and enables you to use up to 4 voices that you can adjust Gain, Pan, Delay and Pitch. Early hardware that provided this effect were traditionally used to create harmonies but have proved over the years to be also very good at producing pitch-shifted doubling effects. Doubler, if dialled in tastefully, can also produce pleasing width effects.

To achieve this, engage two voices, pan one hard left the other hard right. Set the pitch of one to +1 and the other to -1. This slight pitch difference between these two voices blended in with the original direct sound will instantly give you a sense of width. If you feel your material needs a little more, simply exaggerate the pitch differences between voices and modulation settings.

4 - PS22 Spread

In this final episode in this series of tutorials, we take a look at Waves PS22 Spread, a very powerful stereo maker plug-in. 

This plug doesn't delay or detune audio to produce stereo width. Instead, it uses a variety of evenly spaced frequencies across the spectrum to trick the ear into perceiving width. 

The PS22 Stereo Maker plug-in is a suite of three separate stereoiser tools from Waves:

• PS22 Spread: This plug-in produces stereo width by spreading frequencies across the stereo image. Spread includes an LF Spread control that helps to widen or narrow bass frequency range width.

• PS22 Split: This plug-in doesn't feature the LF Spread control, instead a frequency point can be set and the lower end width is narrow by default. The shape of the frequency spread can be altered.

• PS22 XSplit: This plug-in is a variation of PS22 Split.

From this suite of 3 plugins, PS22 Spread is a good plug-in to try first as it offers control over the bass width.

What Do You Think?

There you have it, four different stereo augmentation plug-ins you can try for yourself the next time you need to dial in stereo width in a mix. Out of these videos, which of the plug-ins did you prefer the sound of the most?

Do you already use any of these plugins? If so please share how you use them in the comments below.

Visit Waves more information on the plug-ins used in this article.