I don't know this one
Also french music I thinck, probably Lully also ???
If you record the concert, I would be happy to hear it !
And the CM3 alone are great here.

My take, based on reading and several discussions with Sonare and Norse and others over the years leads me to think it's a bit of license, as the TF omni/card arrays I remember seeing have the cards out at around 110 degrees ("ORTF-ish") rather than straight in ("AB") or at 90 degrees ("NOS-ish"). What I've gathered from the several TF videos I've watched is to not get hung up on a slavishly precise technique at the expense of not trying to improve a bad situation (i.e., placement problems) with some time-coherent arraying. I also think it should be (whatever "it" is) referred to as a "Faulkner-ish" array, because it seems even he is wont to make changes to the placements (without abandoning the concept) if his ears tell him something's not quite right...

I do, however, believe that ORTF, NOS and Blumlein (to name three) SHOULD be approached as definite practical techniques to be mastered before being messed with.

Of course, the above opinions are mine, and are not to be seen as reflections upon those other individuals mentioned.

HB

Yes I've picked up a few variations between videos and printed interviews...TF has used MK 21 and Rode NT6 as centre pair and mostly Rode NT45-O as outer 67cm AB....and anywhere from ORTF to 43 to 47cm capsule spacing...so as TF says it's all empirical ! The 67 cm Omni pair always seems to be splayed out 45 degrees each however.
I wonder if a 47 to 67 Straus Packet array could work ....hmm ?

Another TF array, Abbey road with LSO Bartok/Schosta.
No Rode microphones in this case.

YouTube
at 1'18''

Fred.

Yes, the TF 4 mic array seems to be the main pair choice on this occasion, using probably Schoeps Collette with remote cables, that would tally with the grey finish, rather than the shiny nickel of the Rode's.

Judging by your screen capture shot, I'd guess the inner pair to be 47cm, if the outer omnis are 67, and are all angled at 45 degrees out from centre on Rycote Inv 2's.

There seems to be a pair of M50's as outriggers left and right of the main pair (quads !) and what looks like a LD Neumann over the violin soloist, angled downwards from a reasonable height (unless it's a ribbon ?)

Seems to be fewer spot mics than one might have expected, until you get to the brass and percussion, unless the others are kept very low ?

The same conductor has posted several other Abbey Rd recording sessions videos on his YouTube page, perhaps from the same sessions (or same year ?)

For example : YouTube

Here's a link to more of 'em: YouTube

Just a quick thought. Cm3 pair, in NOS, 10’ up and about 3’ back from conductor podium, with one OM1 as a third channel to capture deep bass and mixed in post, was a darn miracle. Sounds fantastic. Nice wide stereo spread, and bass is deep. Mics are ridiculously good for their price.

Interesting use of the OM1.....was it on the same bar as the CM3's, in the centre or to one side ? Did you use it 'straight' or with a low pass filter to give you the bass extension ? How was the bass without the additional mic ?

OM1 was on the same bar, in the center. Recorded all 3 channels full range, but mixed in post with a low pass filter around 100hz. Bass from CM3 alone was already pretty nice, but to my ear, OM1 punched up the lowest end nicely without needing to EQ the CM3.

So I've had a chance to use my CM3s and OM1s on a few recordings now, two full symphonies and a chamber group.

Something I've noticed is that they need a lot more gain as compared to KM184s or even my AT3031s. Do these really have a much lower output or is it just me? I've used them on my Red 8Pre, my Clarett 8Pre and with my True Systems Precision 8. And their gain is twice as high as other mics.

Well, let's look at the specs. I built a spreadsheet for this stuff that has every mic I own and it's specified sensitivity and max SPL. With it I can can specify an acoustic SPL, the desired signal level in the DAW (after specifying what dBu equals what dBFS), and it'll give me the theoretical gain needed for each mic. It's handy when I'm planning for recording or live sound so I can build presets for the preamps or digital mixers that get me to a starting point.

Anyway... Here's what I get for sensitivity for the four mics you mention after doing the math to convert mV to dBV:

Mic and Sensitivity (dbV)
OM1 -44dBV
CM3 -42dBV
KM184 -36dBV
AT3031 -34dBV

So you can see that there's significant differences.

Let's say you have an acoustical pressure of 90 dB(A), and you want that signal to be +4dBu coming out of your preamp. Here's the gain you need:
OM1 49.8 dB
CM3 47.8 dB
KM184 41.8 dB
AT3031 39.8 dB

If you're adjusting gain with a preamp knob that isn't marked in the actual gain provided, I can see where it can seem like "twice as much" gain is being applied. With a preamp with a linear range (i.e. 2 dB per click) it might be more apparent that you're adding 6-10 dB more gain depending on the comparison.

What makes the KM184 special in this bunch is it's 6-8 dB more sensitive than the Line Audios AND less noisy by 3-5 dB

CM3 definately took a good 10db more to get a comparable level to KM184 or NT5. They even took more than OM1. But with decent preamps, the difference was not really a problem. I used a Zoom F4, and the results I got were very acceptable. Don’t get hung up on numbers, use your ears

The CM3 has higher output than the OM1 and should never require more gain. However the OM1 has deeper bass extension, being an Omni, mostly, so it may skew comparison as typical VU meters are more sensitive as you go down in frequency. As a test: if you notice that a given CM3 needs more gain than an OM1 at 1Khz at 1 meter, there may be a problem.

EDIT= Mea Culpa - I made a mistake. Yes, it does happen.

OM1 Sensitivity: 8mV/PA -42dB.
CM3 Sensitivity: 6mV/PA -44dB.

So yes, the at 1K at 1M in anechoic conditions the OM1 has higher output! Sorry about the mess that followed. MY BAD.

I had my sensitivity figures reversed for om1 and cm3. Now fixed.

And now, FIXED AGAIN (cause they were right the first time). I'd swear I looked on the web site when JP made his first comment and the web site agreed with him.

In the last two concerts I recorded, I used a pair of OM1's, and a pair of CM3's all mounted on the same 3-ft long bar. Since I have one shot at setting levels before I have to hike to the balcony to run video cameras, I found that 40dB of gain in my Midas DL151 interface for each microphone is just fine.

I get good levels in the DAW with 10-to-70 person choirs mic'ed 15 feet away on a 12-foot "mic stand". The OM1's definitely had somewhat more output, probably because of the pattern, and a couple of the peaks came up at -3dBFS (whew!), and the CM3's peaks were lower, but no harm, no foul. Going forward, I'll standardize on 35dB of gain for these situations.

I had my CM3 at 39 dB and I think OM1 at about 37. It worked out great, highest peak was at -6. So they a bit less sensitive, but it’s a non-issue

Tim - this is super helpful info..for me sorting relevant sensitivity and self-noise seems a difficult ask.

I wonder...do you, or anyone else...have experience or feedback on the relevant sensitivity between the CM3s and the Rode NT5s?

I would assume that the Rode as well as being slightly brighter would produce more signal and therefore need less gain than the Cm3 and be perhaps be similar to the KM184 and more suitable for quieter sources:

The specs for the Rode NT5 are below (am I the only one who finds this confusing! ):

Sensitivity: -38dB re 1V/Pa @ 1kHz
(12mV/Pa @ 94dB SPL)
±2dB @ 1kHz
Equivalent Noise: <16dBA SPL
(per IEC651)
Maximum
Output:
+13.9dBu
(@ 1kHz, 1% THD into 1kΩ)
Dynamic Range: >128dB (per IEC651)
Maximum SPL: 143dB
(@ 1kHz, 1% THD into 1kΩ)
Signal/Noise: 78dB SPL
(@ 1kHz, rel 1Pa per IEC651)

This is a handy article:
[ In-Depth: Microphone Specifications Explained - Page 5 of 8 - ProSoundWeb ]

A -38dBV/Pa mic is producing more signal than a -44dBV/Pa mic. When the 94dB SPL testing protocol is used, the sum of the self-noise and the signal is 94dB. The max +13.9dBu output (accomplished with an ear-damaging, jet-takeoff 143dB SPL input) is about 3.8 volts RMS, which will give about -8dBFS in your DAW without any gain applied via a preamp.

Just to keep us on our toes, the IEC 651 standard was renamed to IEC 60651 which in turn was superseded by IEC 61672.
[Sound Level Meter Standards ]

Apparently the audio people are jealously looking at the brain-cramping level of confusion that is routine in the video "standards" world, and stepped up their game to compete for how much per capita stomach acid could be generated among those who attempt to unravel this Gordian knot.

Let me punch this into my sheet. I'll pm you for an email and mail it it to you as well

Edit: I punched the numbers in. There's a discrepancy in Rode's reporting somewhere because if the sensitivity is 12mV, at 143 dB the output would be 13.2 dBu or 11 dBV. it's not a huge discrepancy, that .7 dB.

But, if you wanted 143 dB to register at -1 dBFS on your DAW and you had +4dBu=-18dBFS on your A/D interface, you could add 7.8 dB of gain on a preamp. And as you can see, with the sensitivity of the NT5 at -38dBV and the CM3 at -42dBV, you'll need 4dB less gain on the NT5 for the same source.

Thanks for the explanation Tim.

Generally speaking, matching "errors" within/under 1dB, when it comes to microphones, is totally within "reasonable" specs. It's quite difficult to have tighter tolerances (but possible and many high end mics makers are spot-on) and if you're looking at budget mics, you might end up having to deal with a lot more. I've noticed that since the Digital revolution, many users notice that analog gear can drift by sometimes more than 1dB between channels, settings, identical knob positions on different devices etc. Although it's true that Digital is precise to probably under 0,1dB, it's important to realize that analog gear typically cannot - and sub 200$ mics are rarely perfectly matched unless bought specifically as a matched pair. Always check the spec sheet: a proper specification will have a tolerance, +/-1dB, 2dB, etc. In the 60's it was normal to spec +/-3dBs on most specs, and we're talking Neumann, AKG... today's products are usually released with "optimistic" spec sheets: either guess work, copied from another product, edited by the marketing department... and often without a tolerance window. Times have changed

Sorry for the mess, my post ended up multiplying without prior consent!

Hey guys, see my Mea Culpa above, post #1902 .

Sorry, for some obscure reason my brain totally mixed the specs although I see them every damn day. So yes indeed, the OM1 in anechoic conditions will have more output than the CM3 in the same conditions. Keep in mind that the CM3 being Sub Cardioid has proximity effect so it will skew measurements at less than, say, 2 meters as the bass response will shelf up as the distance drops. In real life situations, it's going to be difficult to evaluate but as distant mics in large rooms, it's safe to say that again, the CM3 will be a bit less hot than the OM1, 2dBs according to specs. Also not the 2dBs difference in S/N ratio, this time to the advantage of the CM3.

It's all good!
My own observance was very unscientific, and based on what I remember from two months ago watching the meters. But it seemed to me the difference in levels was 2-3 db, so not that much. And it was at distance from an ensemble of 50 players, 5 feet back from conductor stand in a large room, so definitely not anechoic.

In the end, the results were good, and that's all I care about

That's what I'd had in my database originally, but I'd swear that when you had your mixup I went to your website and it agreed with you. Did the website change in the last couple of days?

Completely agreed. Re: anechoic: as stated, if the room is large enough and the mics are away from boundaries, the difference between Omni and Cardioid when it comes to proximity effect are basically gone, so you're left with polar response pickup differences. That's why I mention it. When you measure a non-Omni mic in a typical room (as in a house) the mic is close enough for proximity effect to come into play and room modes mess up the measurement. A friend did measurements in a meadow on a quiet day once, said it was much better than any untreated room, a bit of background noise but working with 94dB SPL it was a non issue.

I do regular updates but I don't recall swapping specs, lately or ever. It's probably just an error piggy backed on mine. Sorry guys! Hey, we're only humans. That's a good thing, in my book.