Voxengo MSED plugin for mid-side recording

[Battle Vaughan]

Can anybody fill me in on the workflow for Voxengo MSED plugin for mid-side recording? The information manual the maker provides tells you WHAT it does but never tells you step-by-step HOW. Nothing I've done makes it work, although I can make mid-side stereo OK the hard way, by manipulating the tracks manually. Input appreciated!

[Gary Nattrass]

I presume you have this manual but as you say it is not exactly very comprehensive: https://www.voxengo.com/files/usergu...Guide%20en.pdf

Basically the plug in can do two things:

1: Encode a stereo A/B signal into an M/S signal.

2: Decode an M/S signal into an A/B signal.

SO to encode you feed a stereo A/B signal into it and you can then derive an M and an S feed to record.

OR if you have recorded material with an M/S microphone you can decode this to provide an A/B feed to record.

If you did not know M/S is a technique that takes two coincident microphones and records them as an M on the left channel and the S on the right. This is commonly a forward facing cardioid Mono mic and a figure of eight mono mic to record the S signal. The S signal is then decoded to provide an in phase and out of phase element to give the stereo image.

So your decoder with take this

ch1 left =M
ch2 right = S

to give you this

ch1 left = M+S (A)
ch2 right = M-S (B)

If you have an A/B signal (left and right) you can also use this plug in to adjust the width of it by encoding the A/B signal and therefore increasing the S content. So the more S content you have the wider the stereo image and the less the S signal the more mono the result will be as the S+ and S= out of phase content cancels out.

So the encoder with take

ch1 left = A
ch2 right =B

and give you an encoded M/S

ch1 left = M
ch2 right = S

I personally always record A/B as it is easier to handle but some microphones such as my sony ECM-MS957 or 907 have the M/S decoder built in but it can be useful to play around with the stereo image of any A/B signal.

This plug in is quite comprehensive and the scope for problems is quite high as you could end up with a mono signal that is very out of phase.

I use the BX Solo plug in and it gives a very simple width adjustment of any A/B signal: Brainworx | bx_solo

Sometimes it is easier to think of an M/S signal once decoded as an LCR (left centre right) array where

Left = M+S
Centre = M
Right = M-S

the more S content you have the wider the stereo image and if you decrease the S content you will end up with mono.

Hope this helps

[Battle Vaughan]

Thank you, Gary. I use the coincident figure-8 and cardioid setup and can manually derive the stereo by manipulating the tracks. My question really is about the workflow of the plugin, as everything I have done with it yields odd results. The tracks go blank or one loses amplitude (but with no apparent stereo effect). As I said, the manual gives no step-by-step operating instructions, it mostly just enumerates the features of the plugin without explaining how to use them. Something I'm not getting, because the tracks I make by hand ---tediously --- work fine, and I get nothing useful from the plugin....

[Gary Nattrass]

Hmm I would presume that you would just plug one cardioid mic into one channel and the other fig 8 in the other and it would decode to A/B with a width control.

I will download the plug in and see what it does in my pro tools rig.

[Fran Guidry]

I use MSED regularly with REAPER. I load it as a VST plugin on a stereo track with the mid mic on the left channel, side mic on the right with the positive side pointed house left (stage right). I set the MODE to Decode and leave the rest of the settings at default.

If the mid mic is on the right input channel, I use CHANNEL SWAP to manage that setup. If the side mic is oriented house right (stage left) I use the FLIP 180 toggle to adjust for that.

If your tracks are currently dual mono instead of stereo, you'll need to "stereoize" them somehow in order to feed them through the decoder. I didn't see a mention of the application you're using so I'm not sure how you'll go about that.

Fran

[Battle Vaughan]

Thanks, Fran, I guess I need to go back and play with this some more.

[Fran Guidry]

I got an idea while I was cooking and just tried it successfully.

If you're working with two mono tracks instead of a single stereo track, put MSED on both of your tracks. Set both plugins to DECODE. On the Mid track, hit the SIDE MUTE and on the Side track hit the MID MUTE.

In my test the mixed result was identical to a stereo track with one instance of MSED on it.

Fran

[Battle Vaughan]

Very helpful, Fran, thank you. I've been trying to learn it with an m/s stereo track and getting odd results or none at all. On a hunch I'm going to check that I don't have the mid and side reversed. The manual doesn't explain very well what setup the plugin expects to see, and in fact is sort of unclear on whether to use "decode" or "encode" or "inline", whatever that might be. Thanks to both you and Gary for your input!

[Gary Nattrass]

As a side (no pun intended) note I did a stereo sound training course in the 80's where they said you could experiment with M/S in different ways for doco's etc by using lav mic's on presenters as the M signal and a boom or camera mic as the S content.

Not sure how the non co-incident phase will effect things and never tried it as M/S decoding was always critical with analogue mixers but now we are in the digital age it may be interesting to see what happens.

I personally always use M/S mic's that decode to A/B and record that.