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Recording classical choir: what technique and what mic stand?

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Re: Recording classical choir: what technique and what mic stand?

Postby Guitarking » Sun Jun 24, 2018 8:08 pm

Ah thank you Hugh, I think I'm beginning to understand.
So 2 cardiods in ORTF make up '1' big cardiod so to speak. Which has a certain amount of ' capturing' degrees?
WIth this site you can see the angle you need to e.g. capture the extremes of the choir into the extremes/borders of the capturing angle of say cardiod etc...??
But: in real life: how does one determine the angle of the extremities of the choir? Is there some formula to say calculate the distance the array has to be from the front of the choir if one knows how wide the choir is?? Sorry, my maths are failing me now...
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Re: Recording classical choir: what technique and what mic stand?

Postby Hugh Robjohns » Sun Jun 24, 2018 9:06 pm

It's usually done the other way around, because the distance of the mic array from the choir is generally more important since that largely determines the captured perspective and thus the overall character of the recording.

If the room's critical distance value is known then the optimum distance for the mic array can be calculated... But most people just judge it by ear and experience.

Once the mic position is determined you can assess the required SRA for the sound source layout, and from that determine the appropriate stereo array format to provide that SRA.

This is an iterative process as the chosen stereo array might affect the perspective, and so the distance, polar patterns, spacings and mutual angles may need to be tweaked until you get the precise sound characteristics you require.
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Re: Recording classical choir: what technique and what mic stand?

Postby Guitarking » Thu Jun 28, 2018 8:22 am

Done it! Concert was yesterday.

Collegue of mine who's into maths gave me formula to calculate distance from choir to get the 96 degrees ORTF SRA angle. I had no time to experiment, had to put it down and record...

Some things occured to me. If I look at the SRA site (or the Neumann) app, it appears to me to get the 96 angle the mics needed to be that far away that the mics pointed a bit outwards of the choir (the RSA angle is a bit inside the mics). But with the formula (the width of the choir was about 6 meters) I put the mic stand 2,7 meters before the choir. I sing tenor and was on the outer edge of the choir and the mics pointed a bit inwards. So I expected the stereofield to be very wide; that even the outer edges of the choir would be 'compressed' because the fell outside of the 96 degrees 'lens'. But... to me the stereo width doesn't seem to be widest on my speakers. So either the formula wasn't good, or my eyes are blind lol ;-)

Also, I have the idea I miss a bit of depth. Has this to do with using ORTH, would AB be better next time?
Also, I have the idea it's a bit muffled, but then again, my experience lies in pop music, so maybe I'm used to hyped high ends.
Don't get me wrong, very satisfied for a first time and grateful for all your help, just trying to improve here! Really nice to record a live choir!! Very interesting!

I'll ask the choir if I can use an tiny excerpt to post so you guys can listen.
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Re: Recording classical choir: what technique and what mic stand?

Postby Hugh Robjohns » Thu Jun 28, 2018 1:26 pm

Guitarking wrote:If I look at the SRA site (or the Neumann) app, it appears to me to get the 96 angle the mics needed to be that far away that the mics pointed a bit outwards of the choir (the RSA angle is a bit inside the mics).

Yes. The mutual angle of the mics is 110 degrees but the SRA is only 96 degrees, so the mics should be pointing slightly outside the choir edges...

But with the formula...the mics pointed a bit inwards.

Oops! ;-)

So I expected the stereofield to be very wide

Me too.

But... to me the stereo width doesn't seem to be widest on my speakers.

We need an example to hear...

Also, I have the idea I miss a bit of depth. Has this to do with using ORTH, would AB be better next time? Also, I have the idea it's a bit muffled

I can't remember what you're using as your mics, but 'muffled' doesn't sound right. Some high shelf EQ will probably help though. Depth means different things to different people... what do you feel is lacking exactly?

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Re: Recording classical choir: what technique and what mic stand?

Postby blinddrew » Fri Jun 29, 2018 1:29 pm

Could it be a free field / diffuse field effect? I can't remember if the OP was using Omnis or Cardiods.
(P.S. I know that ORTF specifies cardiod but...) ;)
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Re: Recording classical choir: what technique and what mic stand?

Postby Hugh Robjohns » Fri Jun 29, 2018 2:31 pm

NT55s I think, so cardioid capsules for ORTF. The omni capsules have a mighty peak of +8dB at 10kHz, so they would appear to be equalised for the diffuse (distant) field.

I suspect the lack of perceived brightness or clarity is either down to placement or the room acoustics.... or it could be the choir itself not having great diction I suppose.

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Re: Recording classical choir: what technique and what mic stand?

Postby Guitarking » Sun Jul 01, 2018 9:10 am

I used cardiods.

I think my ears were blocked, sounds like good high end after all.

How do I upload an excerpt from the recording?
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Re: Recording classical choir: what technique and what mic stand?

Postby blinddrew » Sun Jul 01, 2018 9:21 am

This forum doesn't host any content so most people use a private link to soundcloud or dropbox (other file sharing tools are available).
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Re: Recording classical choir: what technique and what mic stand?

Postby blinddrew » Sun Jul 01, 2018 9:06 pm

Just had a quick listen on the laptop and it sounds ok to me, waveform looks fine on Reaper too. There's content all the way up so if you did want it a bit brighter then a gentle high shelf should be fine.
As usual though I will steer you towards the disclaimer in my signature...
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Re: Recording classical choir: what technique and what mic stand?

Postby Guitarking » Tue Jul 03, 2018 11:30 am

Thank you blinddrew!!

Anyone else would like to have a listen?
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Re: Recording classical choir: what technique and what mic stand?

Postby Hugh Robjohns » Tue Jul 03, 2018 11:43 am

Difficult to tell from such a short clip, but it sounds pretty good to me. Nice stereo width. A slightly distant perspective but it works in context. Good job.

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Re: Recording classical choir: what technique and what mic stand?

Postby Guitarking » Tue Jul 03, 2018 7:31 pm

Hi Hugh,

Yeah, that's the strange thing. If I would have put the mic stand closer, it would have been more direct, but even now the mics were pointing a bit inwards the choir, so I was afraid the extremes of the choir would have been compressed, but I have the idea it's wide but could have been wider. That's what's puzzeling me.
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Re: Recording classical choir: what technique and what mic stand?

Postby Bob Bickerton » Tue Jul 03, 2018 9:49 pm

Just a note of thanks to John and Hugh about those app suggestions, they are very useful indeed. Combined with an ‘Airmeasure’ App, you have a complete set of tools for microphone positioning.

Bob
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