how to get a m/s decoded file re-encoded to how it was before?

[MadScientist]

heyy all!

I think the title says all already...I want to m/s decode a stereo file to process its mid and sides independant, and then re-encode it back to how it was before.

the last part is whats bugging me...anyone got an idea maybe?

thanx for your help!

[filin]

Left channel is mid+side, right channel is mid-side.

Several ways to achieve this, here's one:

4 tracks, first two panned left, one containing your mid information, the other for the side. The next pair panned right, same set up, but this time invert the polarity on the track containing the sides data.
You might have to drop the master fader down -6db, can't remember, you'll soon find out.

[MadScientist]

thanx for the tip, I'll try that out!

do I have to duplicate both tracks for this? right now I got the mid and the sides each in a seperate mono track...

[richardswag]

This is a cut and paste that I saved from an old GS post. Thanks to the original poster, whoever it was.

"The basic method is to clone or mult the Left and Right channels so you have four channels in total.

Sum the first pair to Mono by panning both channels to the centre. The 'Mid' information, which is basically your dry stuff that is common to both side, gets a 6dB boost from the summing. The 'Side' information, which is basically your stereo wet stuff (like reverb) doesn't get any boost.

With the second pair of left & right, do the same but invert the polarity of one side. This cancels out the dry stuff that is common to both sides, leaving just the wet stuff (in mono).

Now, you recombine the mix of these two buses (Mid and Side) back into a stereo Left/Right mix. This is done by creating one side by summing Mid and Side and panning to one side. The other side is created by subtacting Side from Mid and panning to the other side. Subtraction is achieved by Summing with one side channel polarity inverted.

If you are new to this - this sounds strange and convoluted. But the mathematics are solid - you really can turn Left & Right into Mid and Side, and then back again to Left & Right with zero loss of informaton. "

[MadScientist]

ok let me see if I got this correct:

to get the m/s signal I simply used logics direction mixer, which did the mid to left and the sides to the right...this I bounced as a split stereo file to get a mono track of each channel.

now I duplicate both, put one mid, one sides to the left and one mid, one sides to the right where the sides are inverted on the right for example!?

thanx for your help guys!

[filin]

Originally Posted by MadScientist

ok let me see if I got this correct:

to get the m/s signal I simply used logics direction mixer, which did the mid to left and the sides to the right...this I bounced as a split stereo file to get a mono track of each channel.

now I duplicate both, put one mid, one sides to the left and one mid, one sides to the right where the sides are inverted on the right for example!?

thanx for your help guys!

yes

[MadScientist]

great...thanks a lot!