Mid Side EQ
Controlling Your Spread

When properly used, Mid Side EQ allows you to widen (or narrow) your stereo image at selected frequencies.

This technique is also called Shuffling or Stereo Shuffling.

It's possible at times to even 'remix' a broken track.

Although you are always only dealing with frequencies, you can give the effect of spreading out the cymbals; raising the bass or sharpening and enhancing the vocals. It's possible to tame a boomy mix without losing punch.

To set yourself up for mid side EQ:

Start with the basic outline I've described here.

If you don't have WaveLab (and Tools One), you can use Voxengo's free MSED plugin in a similar chain:

Start with one instance of MSED set to ENCODE – follow your choice of EQ that has separate left/right channel control – and finish with a second instance of MSED set to DECODE.

The right channel of the EQ will control the centre or mono element of the file and the left channel will control the stereo or side element.

If you don't have an EQ with separate left/right control:

You can use the 'DAW' set up (also described here).

In this DAW set up then, follow Voxengo's MSED plugin in each track this way:

In the top track (the mid channel) place your EQ to control the mono (or centre) element.

And in the bottom track (the side channel) again place your EQ (it should be the same plugin type as the above track) to control the stereo (or side) element.

In any mid side set up this is always an INSERT effects chain.

Each track's full signal must go directly in through their respective chains, without ever using send faders!

As mentioned before...

...what mid side EQ accomplishes is basically a width control confined to selected frequencies.

Reducing frequencies below 75 Hz on the side channel can tighten up the bass in your mix.

I've had many good results giving more definition to vocals (when needed!) by cutting in the range from 500 – 1000 Hz on the side channel, usually with just a half to one dB.

But you can also boost those frequencies in the mid channel if the vocals are really low.

Increasing frequencies with a low shelf below 600 – 650 Hz on the side channel can really give an increased sense of space.

But beware!

If there is already a lot of signal content, especially at the midrange around 250 Hz, you can have a lot of playback problems on cheaper boom-boxes such as excessive vibrations!

Remember when I mentioned how you can shift the panorama of a mix without moving the mono element?

Going back to the DAW set up – insert an EQ with left/right controls into the 'side' channel, and now you can move just selected frequencies. This technique can really help balance out a frequency-based lop-sided mix and give it more fullness.

This can actually already be accomplished with Voxengo's Soniformer plugin.

But heed this warning:

Whenever you do decide to use mid side EQ always use linear phase models.

This way you'll avoid any possibility of messing up your stereo image introducing phase distortions that would be caused by using non-linear phase or tube modelled EQ's.

Return from Mid Side EQ to
Mid Side Mastering

Return to About Audio Mastering Software