Fully Mono compatible Mid/Side techniques?

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Stromkraft
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Fully Mono compatible Mid/Side techniques?

Post by Stromkraft » Fri Oct 30, 2015 9:04 pm

So how can we achieve fully Mono compatible Mid/Side processing? That is when the whole track is heard in mono, what's left and right will not cancel out.

Are there some m/s processing tools that are better suited for this job than others? Which ones? How do you set them up? Please discuss and share your techniques.

A couple of reference sources for Mid/Side are Sound on Sounds' "Processing Stereo Audio Files" from 2010 as well as Izotope's thorough article What is Mid/Side Processing? from last year and the very well made video "Mid Side Demystified" made by Fabfilter.
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Angstrom
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Re: Fully Mono compatible Mid/Side techniques?

Post by Angstrom » Sat Oct 31, 2015 1:24 am

I had 7 minutes free, here's how I do mono safe bass. It's not totally transparent and there are other ways of getting there, but it's flexible. It means I can go in and tweak the racks to get what I need out.

Essentially it needs two chains, one to handle the bass end and one for everything else. I collapse the bass with an m/s EQ8 and handle the top end with a stereo EQ8.
It's totally possible to use a Mid/Side eq8 for the high frequencies (above the crossover point) too, but Stereo mode is easier to understand. If you do try using mid-side for the top-end as well you need to ensure that both mid AND side are passing the frequencies you want up top. Because if you kill off the "mono" of your top end then what remains is not stereo but merely "difference" (between L&R) and if you sum difference together you get 0, also known as silence. So ... if you use M/S for the top end make sure you pass both mid and side of the frequencies you want.

As I said ... it's easier to pass L & R for your top end, so that's what I describe here.

http://angstromnoises.com/ableton-tip-mono-safe-bass/

Phase inversion is a fun tool which can accomplish a lot of things. just picture it as simple maths on each sample step on your waveform.
If L=1 and R=1 then L-R = 0, no difference, it's a central signal. If L= 0.7 and R=0.2 then L-R = 0.5 of difference.
By using tools which affect phase, such as Utility, you can do simple mathematical operations on your signal. Subtract the centre only at certain frequencies by use of a side-chained compressor (Vocal removal !), and other fun things like that.

Stromkraft
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Joined: Wed Jun 25, 2014 11:34 am

Re: Fully Mono compatible Mid/Side techniques?

Post by Stromkraft » Sat Oct 31, 2015 5:45 pm

Angstrom wrote:I had 7 minutes free, here's how I do mono safe bass. It's not totally transparent and there are other ways of getting there, but it's flexible. It means I can go in and tweak the racks to get what I need out.

Essentially it needs two chains, one to handle the bass end and one for everything else. I collapse the bass with an m/s EQ8 and handle the top end with a stereo EQ8.
It's totally possible to use a Mid/Side eq8 for the high frequencies (above the crossover point) too, but Stereo mode is easier to understand. If you do try using mid-side for the top-end as well you need to ensure that both mid AND side are passing the frequencies you want up top. Because if you kill off the "mono" of your top end then what remains is not stereo but merely "difference" (between L&R) and if you sum difference together you get 0, also known as silence. So ... if you use M/S for the top end make sure you pass both mid and side of the frequencies you want.

As I said ... it's easier to pass L & R for your top end, so that's what I describe here.

http://angstromnoises.com/ableton-tip-mono-safe-bass/

Phase inversion is a fun tool which can accomplish a lot of things. just picture it as simple maths on each sample step on your waveform.
If L=1 and R=1 then L-R = 0, no difference, it's a central signal. If L= 0.7 and R=0.2 then L-R = 0.5 of difference.
By using tools which affect phase, such as Utility, you can do simple mathematical operations on your signal. Subtract the centre only at certain frequencies by use of a side-chained compressor (Vocal removal !), and other fun things like that.
Thank you Angstrom. I'll evaluate this useful technique and share links to your site entry if this comes up.
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andy_cytomic
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Re: Fully Mono compatible Mid/Side techniques?

Post by andy_cytomic » Thu Nov 05, 2015 3:24 am

The easiest way to handle bass mono compatibility is to make the bass mono at the source. If you are panning a synth or sampled bass yourself then don't. If you are adding stereo widening effects then make sure they only operate on the upper frequencies, there are usually high pass filters on modulation effects like chorus to prevent these issues so use them. If you are using a stereo mic'd source then you can use a crossover to make it mono before mixing it to a buss. You may need an all pass correction filter / phase flip on the left or right signal if the bass has been recorded with stereo mic techniques, or perhaps even just throw one of the low passed signal away entirely.

Remember that a crossover will alter the phase of both the low and high passed signals, so you are best off handling the mono compatibility of bass at the source before being mixed to a buss, that way only the bass signal has any changes in phase, not the rest of the mix.

Once the bass has already been made mono at the source then further EQing on busses using M/S will work just fine, alternatively you can have a bass buss and an everything else bus and only to the M/S EQing on the everything else bus, then add them both to the final output.
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drez
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Re: Fully Mono compatible Mid/Side techniques?

Post by drez » Thu Nov 05, 2015 4:15 am

Thanks a ton for that, Andy. Dropping that in evernote!
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drez
Posts: 497
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Re: Fully Mono compatible Mid/Side techniques?

Post by drez » Thu Nov 05, 2015 4:25 am

...and you too Angstrom :P :D
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http://www.soundcloud.com/dreznicek
MacBook Pro Retina Laptop, 2.7Ghz i7, 16Gig RAM, 500G SSD, Live 9, Push, Novation SL25 Mk2, iPad (TouchOSC, Lemur, Touch-Able), Reason

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