In the beginning of February, I will be recording a small string orchestra (2 first violins, 2 second violins, 2 violas, 3 cellos and a double bass, plus violin soloist and Armenian duduk soloist) in a reasonably big, pretty high, yet very reverberant hall with mirrors on all sides.

We did a "demo" recording some year ago and the artist liked it and even though I tried to persuade them to move to a "warmer" hall, the circumstances are such that we will record the album session in that same hall, after all. The solo violinist, who is also the leader of the project, also likes the sound and feels it will be fine. I am a bit reluctant.

Here are two examples from that demo session - both full mix and ORTF pair only:

https://samply.app/p/vaQxYO9rHwqREBjIeZqD

Now I wonder if I should simply replicate the set-up and leave my new toys - omnis, at home or should I risk another set-up.

I like the ORTF only version, but there is too little orchestra vs soloists in it... (and I wonder if spaced omnis would make a fuller sound, if it is possible to use them in that acoustics). A mix is what it is for the demo. But the options to change the main picture were not all that great - couldn't make it sound much drier or warmer with spots...

It will be a bit different this time - a bit better orchestra and additional double bass, that was not present for the demo. The soloists are the same, only the violinist has a borrowed old italian violin now, that also sounds nicer.

Still, the acoustics will be the same. I can maybe open the side doors - they open to a big marble lobby - still very reverberant, but maybe a bigger space with more distant reflections could be nice. Because when all the doors are closed - we have mirrors all around. There is no budget to get some panels in... borrowing transportable panels and transportation is not possible this time.

I wonder if I should try and minimize the side reflections with some spaced MKH30s a la Faulkner array? To Zoom in on the orchestra and also place the soloists so that they don't dominate the picture as in the demo ORTF, where they are much louder than the orchestra in the main pair.

Also, the violins will be sitted, they are standing in the demo version. So the balance to cellos and double bass will be better.

I have an option - 2x MKH30s plus maybe two omni outriggers close above violins and double bass and mixed lower (?) - with more direct sound than room and spots on everything else, or to try again the MKH40s in ORTF plus mono spots... or risk with Big AB (Gefell M221 with balls), stereo spots on violin (spaced MKH30s) and duduk (spaced MKH40s) to get nice 3D close sound of the soloists and mono spots on the rest (CM3s, MKH40). Adding Big AB to taste (if this will work at all there)

We will have a rehearsal to try out a day before, but I wonder where to start... if the hall would not be a glorified "bathroom", I would simply put up the Big AB and the spots, including stereo spots on soloists, but I wonder if it would work... Or maybe risk with Onno pipe - Gefell M221s in the center and MKH20s at sides - and just catch the whole washy picture in all its glory - find a good balance with this (a washy acoustics when the direct source is much closer doesn't bother me) and maybe only put a spot on double bass that has a sort of mini solo somewhere in the piece...
But I fear the reflections from the mirrors are so loud that it will make any such set-up overly bright.

A lot of considerations, some brainstorm might help.

That's the place:

Hmm never recorded a tsiranapogh (Duduk)

Interesting.

You sound like you have thought this through quite well.
Rehearsal? lucky chap!

I'd be tempted to get some close micing spots just for extra safety.

Otherwise if they are happy....

On your recordings yeah ORTF sound posh, but the other has a kind of liveness I like. The duduk blends well with strings. I think its going to sound fine whatever you do!

Thanks, I hope.

Yes, I am indeed happy that there's a rehearsal day... a safety net.

Still not sure what I'll set up first. Probably the risky one with Big AB and resort to what worked well enough in the end if it won't work.

Not sure spaced omni main pairs (a la Onno pipe or 4mic DECCA), would work... don't have enough experience with those, either. I like the sound when I hear other recordings, but not sure how to apply it here...
I am really tempted to try it, though. But need another's voice of reason saying - don't bother.

With Big AB plus stereo spots I know I can rely on direct close mics and the Big AB can only be for the ambience... no need to rely on it for definition and stereo picture.

Don't know how much experimentation will be possible during rehearsal... tearing setups down, putting up others... probably not three or four different ones - two at most...

On tech I like is the Faulkner spaced array.

Couple of wide Omnis with pseudo ORTF Cardioid centre pair all on one bar.

Its a bit like a camera lens you can pull back or zoom in a bit after. Solves some room balancing issues. Obvs if time is short you will not be experimenting, but worth a mention.

I might try exactly this one and the "risky" one and if none works, the one that was OK before...

Just do my method: record too many mics and sift through the rubble afterwards LOL

The Faulkner spaced array is very versatile. Worth a look (listen), but not crazy different.

Let us know how it goes...

You can create a room within a room with acoustic curtains, horizontal bars and a few stands.
I use standard acoustic curtains (stairville 500gr/m² 3mx3m) which I attach to a Manfrotto bar (272B) and 2 stands.
This has saved my day on more than one occasion.
The hall is the hall, whatever technique you use, you will record the hall. If the hall is not to your taste, transform the hall.

Yes that's not a bad idea.

I see some quite imaginative acoustic treatments on various European classical recording.

I think this may be a live event which would be an issue, but I encourage people to experiment (if they have the time)

Settle back with Tony F and see if any of his recommendations (and the circumstances which drew him to them) mesh with your upcoming scenario ?

His 4 mics on a bar is certainly worthy of consideration

https://youtu.be/8uCcFIyJJ-w?si=NlxM8HuRq1pMjAB8

One thing I failed to fully notice 1st time round: mirrors.

I use to see a lot of them in London studios (no not that, I'm not in Oasis). Remember them at Abbey Road 3 (long time ago) and there was a place I used to use, Red Bus, off Edgware road that was covered in them.

Acoustically not great, I imagine they are quite reflective

Yeah get some fabric covering worse bits. (Near mics)

Mirrors, glass, drapes, plaster and hardwood floors - it takes blend of materials to make a good-sounding space. Dead is for pop studios. Decca seemed to make Sofiensaal work well despite a lot of reflective surfaces...

Mirrors on the celling (and pink Champagne on ice).

Sofiensaal ? Yeah boy, now we are talking. The swimming pool.

Those Decca recordings are by far some of the finest ever made. The Ring is sublime...

This is what happens when serious people, recording serious music, in a serious venue, with a serious conductor and a very serious orchestra.

Seriously.

My approach would be:
- put a carpet underneath the feet of the musicians, to keep the early reflections soft. This will create a better distinction between core sound and wall/ceiling reflections;
- pile up as many of those chairs (in various positions) up against the walls surrounding the group. This will diffuse a lot of the flutter echos occurring in the corners between floor and walls;
- add curtains on stands close to the walls (especially in corners and in front of the walls closest to the players) if still needed;
- make the orchestra group sit in a half circle around a pair of pressure omnis, with all instruments at the same distance to the mics. (I would suggest a Blumlein small AB (22cm max) with shuffling.) Your height may be pretty low to pick the celli up fine. I would recommend to put the celli on risers, so you can keep the mics at a better height for the violins. Your group array should be behind the back of the soloists;
- mike your soloists separately with spots and mix them into the main orchestra image.

In general I have noticed that you keep your main mics much higher than I would ever do. High positions result in a scratchy violin sound. Better is ear height of a standing person, with sitting violins. High mic positions are often chosen to keep early floor reflections separated from the direct sound, but it is better to do something about those reflections with other means, such as carpets and diffusors. (Do you have diffusors in your studio? Bring them and lay them flat on the floor in the direct reflection area between instruments and main mics.)

By doing the above you get a lot of control with maximum sound quality. Your soloist spots may need a little of added reverb to melt with the orchestra sound. Good luck!

P.S.: you may also try the above setup with the soloists facing the accompanying group. Makes it more easy to separate them from the main pickup.

My understanding of Blumlein is fig 8’s, as coincident as possible, with 90 degree angle between the active faces….so are you suggesting to retain the angle but separate the fig 8’s by approx 20 cm on an AB bar ?

No, I'm speaking of Blumlein's small AB, NOT what we generally call "Blumlein" (crossed fig8's). The man has coined many different arrays.

Do you have a reference for this? This the second this has been mentioned around here, but I've never read it anywhere; the only 'small AB' connected to Blumlein I've ever heard of is head-spaced with a baffle between.

https://www.phaedrus-audio.com/binaural.htm

From that same website, check out this page under the header Blumlein δ (delta): https://www.phaedrus-audio.com/shuphler3.htm The 22cm (instead of 20 cm) is given in case the baffle is seen as optional. In the table further down that page the same Blumlein Shuffler is recommended for: near spaced omnis, near spaced cardioids, near spaced hypercardioids, binaural microphones, phased array cosines (Faulkner). The whole idea of the shuffler is that phase differences of the lower frequencies between L/R channels are converted into intensity differences, in order to get the correct bloom of widely embracing low notes. From my experiments I have learned that it may be useful to angle the capsules out a bit (no more than 45 degrees) in order to profit from the difference in frontal impact representation of the higher frequencies.

That just reads as Phaedra coining the term "Blumlein Delta" to the process of applying a shuffler to headspaced recordings.

I find no reference to Alan Blumlein suggesting 22cm omnis without a baffle, nor coining the term "delta" to the use of a shuffler.

Let's face it - when it comes to Alan Dower Blumlein, it is better to go back to English sources: http://www.innocentear.com/page12.html There are a number of ways to impliment the Blumlein Difference (or Delta) Technique.

If it were me, I would record just the way you did, and then I would also record sections with relatively tight mikes. This gives you the options of either being able to use the main pair or build a mix entirely with sectional mikes, or something in-between.

Although I am always a fan of recording the room, it doesn't always work when the room is a problem. So give yourself options.

If I were recording, I'd use an ORTF-like arrangement with hypercardioids, which gives you a lot more control over side and rear reflections... but I'd also set up sectional mikes because channels are cheap and retakes are expensive.

And... I don't know the music either. Maybe the music is -supposed- to sound like it's in a bathroom. This is the first thing to find out.
--scott

I’m assuming a similar degree of shuffling can be accomplished in a DAW, versus employing the Phaedrus hardware unit (although the latter obviously supplies quite a few more subtle variations of the process) ?

Nowhere in Blumlein's patent are the terms "Difference Technique", or "Delta" found.

It describes just three ways of recording stereo (which the paper calls "binaural"):

1. Head-spaced baffled omnis (with shuffling for speaker reproduction).
2. MS with two figure-8s (because at the time the only usable directional mics were figure-8 ribbons).
3. 90 degree crossed figure-8s (which got named for him after his death). A subset of this was described for situations where different angles might be suitable)

in a reverberant and highly reflective room/hall, i'd be tempted to use blms in ortf as mains (if not conventional m/s or then a soundfield mic system, relatively high up to avoid floor and ceiling reflections) and directional (mono) spots so i could build the mix on the signals from these on all instruments (plus a pair of far ambis in wide a/b)... - short: (except for the ambis) i'd do anything to pick up too much room sound and i would try to minimize spill.

The basic process is described as a gradual widening below 700Hz, which could be done with any M/S-EQ combo. Phaedrus does also make a software version of the Shuphler, which works with Mac OS.

Isn’t there some uncertainty about whether fig. 8 mics (vs omni) even existed in Blumlein’s lifetime….as this extract from the Phædrus website suggests ?

“Simply put, the earliest use of the term (coined by no less than Alan Blumlein himself), refers to the processing of near-spaced omni' microphone signals so that they reproduce correctly on loudspeakers.

The second Shuffler was invented some twenty years later for the processing of crossed, cosine (figure of eight) microphone signals to give better realism.

Why use the same name? Well the later "Shuffler" was invented by the same team who had worked with Alan Blumlein before he was killed in the Second World War. Perhaps they sought to honour him in adopting the term which derived from him?”

Certainly RCA was making ribbon mics in the USA by 1931 and the Type 44 made its debut in 1933. In the UK, BBC and Marconi released their ribbon mic in 1934, so Blumlein definitely had access to figure 8 mics and that lead to the coincident techniques that carries his name.

That’s clearly factual information which supports the contention that his research and patents specifically refer to fig 8 mics ….I’ll need to go back to his original papers to see which mic types he cites in this context

These comparative ‘Mic Tech Analysis’ set of videos might be helpful (or at least interesting) to the OP in regard to various main-pair approaches to recording in large spaces (be sure to check the extended ‘Description’ section of each video):

https://youtu.be/CJ61erZrVl8?si=wpktny4Pvii_Ix95

https://youtu.be/N-QUadc1uKk?si=luihuDRxeI8rxqoW

https://youtu.be/GC7CTRzjjnA?si=3QkaXzq49glszb3a

https://youtu.be/BL3ky_cmpsE?si=6Dfp8QCF2dSTXh6W

https://youtu.be/0P-AoenC5Rk?si=9YSPx3u6m7PTz6WC

https://youtu.be/iDFY_rOoO6U?si=Ed3W-w3HyUYU7N9F

When he was writing his patent in 1931 (United Kingdom patent 394325) he only had access to omni mics. By the time the patent was published (1933) he was on the cusp of working out his crossed figure 8s.

RCA's first ribbon was the PB-31 released in 1931; Given the affiliation between EMI and RCA, it's likely A. B. had access to prototypes some time before that.