Setting: recording an average sized choir placed close behind an orchestra with the choir setup in the standard SATB and you plan to use 4 mics, one for each section.
Which mic pattern would you choose: wide cardioid, cardioid, hyper cardioid, figure 8?

Cards, one for each section. Reject that orchestra!

D.

Figure 8, especially ribbon, are worth considering since you're using four, and it's not a large choir.

'8' nulls aimed at the orch (so, height of the back row, and pointed down) will reject more than cards and whatever orch spill they do pick up will have a far more even response than cards at 180 degrees.

Here, for example, is @ TonyF using Coles as flanks on choir behind orch:

I don't have four figures-of-eights.

Man, those choir mics seem SO high to me. Can't imagine there isn't a lot of room in those. TF is a pro so I am assuming that worked for him.

D.

i guess there will be some percussion instruments, possibly at the rear of the orchestra/close to the choir?

of course things always depend on the room, the setup, the available gear, the desired result etc. - i'd use directional mics (most likely cardioids), put baffles behind them, go relatively close and use efx when mixing...

The last recording project I did with orchestra and chorus was in January with the RPO and a children's choir - Finchley Children's Music Group - in Prokofiev's "Winter Bonfire".

We decided to have the choir behind the conductor to give closer contact to the conductor, and to help the choir hear the whole orchestra, not just the back of the orchestra.

I love ribbon mics and have a collection of Beyerdynamic, Rode, Royer and STC (i.e. pre-Coles) - listed in alphabetical order - all of which I love dearly. On this occasion I used a pair of RODE NTR's for the choir.

Before anyone asks, they are RODE NTR's I bought on REVERB.

Tony, I have to tell you how much I appreciate this as a choir director, and also as someone who has sung in many choirs behind an orchestra while struggling to hear myself in context. I wish such a thing were possible in a live performance.

//

Speaking of which (and this question is for everyone), I will be part of a Mozart Requiem (Levin completion) performance in a few months, and as of yet no recording outfit is contracted. I have offered my services and am waiting to hear back. A 'proper' setup with SATB section mics will be required as we will be joining with another group to make about 170 singers total. With smaller choirs behind orchestra, I have had good results with just one Gerzon pair of 4011's very high, but I feel that will not cut it here.

If I get the job, the mics I own which could be made available for the choir are a pair each of:
4011
CM3
CM4

I was considering using the four CM3/4, but I think bleed from the orchestra will be a problem. I'd rather not spend a lot of money on dedicated mics for this, as choir with orchestra is something I only record a couple times a year. Would something like the RODE M5 be serviceable?

Here's an idea:

I believe you have Omni1s (or OM1s) no? Make a set of hardboard or plexi boundaries the size and shape of the Neumann GFM132, tape the mics securely to them, then mount the plates on stands just as you would regular mics, with the plates positioned vertically. You get a half-omni pattern towards the choir, and more rejection of the orch than with cardioids (a lot more than with the sub-card CM3/4).

If no OM1s (or other small omnis) , then the CM3/4 could serve, with the fronts of the mics pointing down; these have very good response at 90 degrees. The mics (not the plates) mounted pointing straight up would likely work fine too, with possibly even more rejection of orch.

You'll still get bleed at frequencies below the boundary plates' shelf freq, (they'll be omni at those freq) but that's unlikely to be a problem..

I like this idea. How wide a spacing would you recommend for an omni pair used this way?

I do have a pair of OM1, but better yet I have a pair of DPA 4061 along with a pair of the tiny 75 mm BLM6000 boundary mounts. They would certainly be even less visually obtrusive for the choir.

My concern with the orientation you recommend is the tight spacing we will have on the stage between the rear of the orchestra and the choir, and the huge size of the choir on risers that will curve inwards at the ends. The mics would have to be set very close to the choir in order to put the entire orchestra in the rejection zone, so the outermost singers may be singing more or less toward the back of the boundaries.

What if I were to orient the boundary plates 45deg relative to the floor (capsules essentially aimed up and over the top of the choir) and with just enough opening angle to catch the outer edge singers in the hemisphere pattern? The orchestra should still be effectively rejected because the back side of the plates would be aimed directly at the winds and percussion. Does this make sense?

I assumed were planning four across the choir, so evenly spaced across.

Yes tilting the plates up can work very well; the response is quite consistent for the whole hemisphere in front; any inconsistency is in favor of about 45 degrees off center as there is often a bit of a peak directly on axis.

If you don't have four omnis to use, the center ones being CM3/4s should work well.

Agree with fig 8 comments above. Best recording I ever made with choir and orchestra had three MKH30 on the choir (positioned behind the orchestra). Isolation and tone.

It just hadn't occurred to me to use boundary mics for choir behind an orchestra. Sounds like a great way to get smooth, wide coverage with the mics, while also drastically reducing bleed from the orchestra.

I have four 4060/1 DPA mics, with the boundary mounts that comes with their kits. If I want to mount them vertically, attached to plexiglass, between the orchestra and choir, how large a sheet of plexiglass (for each mic) would be required?

Thank you.

DG

Depends entirely on how low a frequency you want them to remain directional.

For instance, the Neumann GFM132 becomes fully omni at about 400Hz (see below). If one made a copy of the GFM plate but increased the size so that the longest side were doubled, that freq would drop to 200Hz. I would think that a transition to omni at 400 would be fine for choir spots.

The larger the boundary, the lower the freq at which this occurs. Below is also the formula published by Crown for determining size vs freq.

The attached Neumann research paper is worth a read.

Very helpful.

Thank you, so much.

DG

I only have two 4061, and was trying to get by without making plexi boundaries and just relying on the little rubber ones. Just the two mics on tall stands at the 1/3 and 2/3 points L-R across the choir. I fear the small size of the boundary discs won't do much to reject the bass range, though. I will test at home regardless.

I'm also still considering getting four RODE M5 and distributing equally in the traditional way instead. They are quite cheap on the secondary market; plenty of new ones for sale.

What are "the little rubber ones"?; don't see anything like that among the 4060 accessories on the DPA site.

As pointed out in post #13 , even the GFM132 plates are only directional above 400Hz; anything smaller than those aren't going to reject much of the orchestra.

No need to trouble with plexi; 1/8" hardboard is easier to fab and just as effective.

These:
https://www.dpamicrophones.com/acces...0b?variant=163

Clearly too small to do much of any rejection on their own.

I appreciate the advice on making Neumann-style plates, but I think I'll just go with the traditional 4 small cardioids.

Funny they don't show them as accessories on the mics' web page.

The 3" boundaries will reject from behind just as well as any size, it's just that the rejection will only begin at a very high frequency; clearly intended only for use on floor, wall, piano lid, etc.