simple stereo extraction from L+R and L-R mid-side?

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JR.
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simple stereo extraction from L+R and L-R mid-side?

Post by JR. » Thu Dec 13, 2018 1:33 pm

A good friend recently had a horror show trying to play his stereo program through a large convention hotel PA...(sounded like crap).

He gave me a frantic phone call at the 11th hour and I got him through by suggesting he just drop one of his stereo sides and run mono..

But now I'm thinking it would be hip to mix his original files as L+R and L-R on the stereo tracks. Then after the fact either use the L+R mono feed, or derive stereo with a simple matrix...

This seems a lot like the popular M-S boxes... Any thoughts?

I am trying to KISS. My friend is more of a recording guy than live sound guy...

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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mediatechnology
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Re: simple stereo extraction from L+R and L-R mid-side?

Post by mediatechnology » Thu Dec 13, 2018 2:48 pm

So what made it sound like crap?

In that setting mono, or near mono would be my first choice.

A lot of modern stuff is mixed too wide particularly in the low end.
Or it contains out-of-polarity elements which have no L+R at all.
When mono'd they disappear.

The Studer 90° Filter is something that has piqued my interest: viewtopic.php?f=6&t=1055
There was a sim of this circuit at GroupDIY: https://groupdiy.com/index.php?topic=62 ... #msg797074

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The 90° filter might make a better mono than L+R.
I've heard a lot of stuff in background music situations recently that might have benefited from it.

The Width controller might be an option too. https://www.ka-electronics.com/kaelectr ... _Width.htm
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JR.
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Re: simple stereo extraction from L+R and L-R mid-side?

Post by JR. » Thu Dec 13, 2018 4:39 pm

mediatechnology wrote:
Thu Dec 13, 2018 2:48 pm
So what made it sound like crap?
I wasn't there, but the union guys were taking the audio feed from a 1/8" headphone jack.
In that setting mono, or near mono would be my first choice.

A lot of modern stuff is mixed too wide particularly in the low end.
Or it contains out-of-polarity elements which have no L+R at all.
When mono'd they disappear.
that was my speculation and why I suggested he grab just one leg of the stereo, and that apparently worked. (Could also have been crashing a wimpy headphone output by shorting L to R, or something weird like that).
The Studer 90° Filter is something that has piqued my interest: viewtopic.php?f=6&t=1055
There was a sim of this circuit at GroupDIY: https://groupdiy.com/index.php?topic=62 ... #msg797074

Image
Image

The 90° filter might make a better mono than L+R.
I've heard a lot of stuff in background music situations recently that might have benefited from it.

The Width controller might be an option too. https://www.ka-electronics.com/kaelectr ... _Width.htm
I am looking for something "really" simple.. In the future I expect him to bring a mono, or at least mono compatible mix, with a robust send that can melt any funny loading :lol: . My L+R and L-R idea is probably too complicated for the situation. This is not rocket science and I think he just got a bad crew... (I talked to a sound guy friend who lives in the same state a few hours away, and said that he has heard horror stories about that venue.)

They were feeding a midas digital console and had JBL line array, but apparently not enough "give a sh__" about the final sound result. The union pukes threatened my friend with fines and/or physical harm if he touched the midas console. (While I doubt that would have fixed his issues).

I told him if he gave me more than just 2 hours notice next time I could hook him up with real sound people in several states.

JR

PS: There are also commercial interfaces (like cute little baby DI boxes ) that accept 1/8" and feed 2x TRS phone or XLR, so probably not a unique occurrence for "whatever it takes" sound reinforcement.
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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mediatechnology
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Re: simple stereo extraction from L+R and L-R mid-side?

Post by mediatechnology » Thu Dec 13, 2018 5:09 pm

I have a "mono" portable radio with a 3 conductor 1/8" connector.
When you plug a 3 conductor to RCA cable into and monitor the feed the polarity of Right is reversed from Left.
I'm not sure why it does this, but this radio would sound like crap in any venue if used as a "stereo" source.
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Re: simple stereo extraction from L+R and L-R mid-side?

Post by JR. » Thu Dec 13, 2018 5:42 pm

There were a few classic stories about mono compatibility... I forget the song, it may have been a Madonna song a few decades ago, but the "new" hip stereo effect was clearly not mono friendly :roll: . They released the recording and almost immediately got complaints from some mono AM radio stations (in Canada IIRC) playing the music that was clearly AFU. They quickly recalled and re-released the music without the bogus stereo efx.

Every serious recording console I ever designed had a mono switch...common practice back in the day to test mono compatibility. I even put a stereo/mono switch on my last phono preamp to appeal to professional broadcast customers (didn't help).

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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Re: simple stereo extraction from L+R and L-R mid-side?

Post by JR. » Thu Dec 20, 2018 1:28 pm

My old friend hasn't answered two of my inquiries about the mono compatibility of his backing tracks... That probably gives me my answer about the root cause of his problem.

JR
Don't only half-ass tune your drums. Visit https://circularscience.com to hear what properly "cleared" drums sound like.

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Re: simple stereo extraction from L+R and L-R mid-side?

Post by emrr » Fri Dec 21, 2018 12:20 pm

So many synth and piano samples don't work in mono, they have 'enhanced' stereo phase issues. You can't even pan them in slightly without them falling apart.

I remember a mastering session in which I'd done half a record, another studio the other half. One of the tracks from the other place had bass DI and bass mic which they'd hard panned opposite, and they were in a very bad phase relationship which collapsed in mono. That track got remixed.....
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mediatechnology
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Re: simple stereo extraction from L+R and L-R mid-side?

Post by mediatechnology » Fri Dec 21, 2018 2:57 pm

So many synth and piano samples don't work in mono, they have 'enhanced' stereo phase issues. You can't even pan them in slightly without them falling apart.
I keep hearing and reading that complaint. There's something odd in this track: viewtopic.php?f=11&t=1007
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