I think the unjustified obsession with the Decca Tree is that engineers are still looking for formulae in how to record, instead of just listening and adjusting. Always the best way to go.

Clearly, and this is why the understanding of exact concept should be important, a Decca tree has the outriggers when the source size dictates it.

If the source is big, three mics would never be a decca tree.
For a string quartet, a decca tree with outriggers would stop being a decca tree.

The reasoning being, the decca team would never have done those things.

Richard King mentions (nay…he invents) the concept of the “Expanded Tree”, for recording chamber orchestra, in his book….section 16.2 page 170-1

He eliminates the outrigger/flank pair of the 5 mic Tree, and extends the Tree’s rear AB pair to occupy a position midway between the outriggers and the original Tree’s rear pair.

It’s shown via illustration/text below and discussion in the related thread….>>>

Richard King book and the "Expanded Decca Tree"

Hopefully this will keep the fires of trad dogma outrage stoked a little more…I haven’t used the method myself, but it looks intriguing !

This is not ORTF, though. It's a variation on spaced omnis. It might be a great thing especially for something like pipe organs where you really need that extension, but it's not ORTF.
--scott

I hope you didn't really understand my post as serious, not a joke that it was? And that your reply is a deadpan joke, too.

I honestly hear people saying things like that so often that it's hard to even notice it when it's a joke!
--scott

Yes; he did have a goal though and, inspired by the Decca technique, hung 3 mics 6m high over the stage.

I was surprised by the robust sound with only three mics. There could be a lesson there to be learned that is lost when all the response fall into the ‘knee-jerk, nit-picking’’, boosting.

That sounds an awful lot like the Mercury technique and not the Decca technique. The Mercury triad works well and gives a good image and a first-row-seat perspective, but also has a sense of depth that I find unnatural (but which some people really love).
--scott

Hu !!! Ok, I only recorded a whole orchestra (and there was also a choir !) with a large 3 omni mics array (NOT Decca tree !)
Sorry to have posted it in a DECCA tree topic...

Just to explain some remarks about the balance between the strings and the winds : the brass was mostly pro and the strings was mostly amateurs and not enough. So the balance problem was real in the theatre. The 6m is probably also a cause of the problem.

I wouldn't even consider that quartet setup of King's to be a stereo array; closer to three mono pan-potted channels to concoct a very artificial stereo result.

If the the L and R are hard-panned left and right, the stereo image would be laughably wide for a string quartet.

________

I'm sure it's been linked here before, but King has some great ideas in this interview:
https://www.soundonsound.com/people/...stic-ensembles

I see no "boosting"; but I do know that one can hang 3 mics in a "non-maned" manner and get a decent recording- and most of us have.

Until you, I or others have tried and verified the outcome of this method, I’d be hesitant to dismiss out of hand anything King suggests as ‘laughable’.

BTW…this Expanded Tree is specified for use with Chamber Orchestra and not a string quartet (the diagram shows 5 sections incl woodwinds/contrabass)….there is a difference between the two you should be aware of ! Now, as for 10-12 feet spacing on the rear pair for a string quartet….yes I agree, that would be funny

Since the accompanying text recommends matching the output of all 3 mics, and makes no mention of hard-panning…this differentiates it sufficiently from the (quite-tightly specified) variable gains and selective panning-in of the 5 mic Decca Tree. In other words, on the Expanded Tree, pan away ‘til your heart’s content….!

King’s omission of specificity here can be taken as an invitation to use one’s ears to optimise results, and in the supplied ‘quick start’ table I included above there’s sufficient dimensional adjustments recommended (according to room size and ensemble width, as he writes there) to encourage experimentation and variation…for fun and profit !

NB…no use of APE spheres mentioned in this context either by King, which I’d open up for discussion….would they help or hinder in this context ?

Or if you prefer, there’s always ‘the other’ approach to chamber orchestra…
https://youtu.be/B6yUmxP-5wI?si=DFc1NtVlu0InEGT5

Scoring session? SO many microphones.

D.

Hello, after looking at multiple topics on this forum I am now wanting to ask a few things.

I don't have the budget for M150's, or good replica of M50's, nor DPA's or Schoeps with balls.
Currently I own two Oktava Mk-012 MSP6 pairs (one of which is moddified with Michael Joly circuit), and three AKG SE300B (but only two CK92 omni capsule sadly).

I don't know if working with these would be adequate for a Decca ? (although sonically much different, but perhaps still pleasing in a way), or maybe should I go the route of LDC for a Decca array ?

I'm thinking maybe something close to a C414EB, or older style C414, like an Se4400 (not the "4400a" but the brother of the T2), or the more expensive side the Peluso P-414, or perhaps even a C12 clone, like the WA-CX12 ? (that would make for a pretty massive tree, alought I've seen C12's on outriggers, at Abbey road in particular.)
It may result into an intresting sound (although much diffrent than the traditionnal appraoch, I am aware).

I'm going on the top of my head here, but I'm guessing other engineer have tried C414's on Decca configurations ; how does it sound ?
I know the that in omni they tend to react more in a figure 8 pattern in the highs.

Thanks.

Three MK012s with APEs will get much closer to the behavior of a true Decca Tree than any LDCs would, which Decca never used beyond a handful of very early experiments which they deemed unsatisfactory (baffled, closely spaced M 49s).

40 or 50mm APEs on MK012 will not have the top-octave or so brightness of M 50s, but many feel that M 50 are actually a bit too bright for the digital age.

I've tried 40s and 50s on MK012 and much prefer the 40s; the 50s producing a rather 'pushy' sound in the upper mids/lower treb. Your AKGs w.CK92 can serve well for outriggers; with them I'd use 50mm APEs, as they have less top-lift than the Oktavas.

Fitting the CK92 with APEs can be a bit tricky, as it's not immediately apparent what the location of the diaphragm is within the capsule, which the hole on the APE needs to line up with. A cutaway diagram of the capsule would be helpful, if you can find one. I disassembled one many years ago, and to the best of my recollection the diaphragm lies approx 1/8" below the bottom of the front slots. I was always puzzled by the CK92's side slots, which I've never seen in any other omni capsule; bottling these up inside an APE may affect the response.

In a pinch, LDCs can serve as outriggers, but the total sound will be a bit of a deviation from the classic Decca sound.

An all-LDC 'tree' can sound lovely, but having such different frequency-dependent directionality, and slower transients, the result will not have the 'sparkle' nor stereo structure of a true Decca Tree.

Thanks for the reccomodation, but how can I find 40mm accoustic balls for the MK-012 ? Especially considering the "cup" shape of the capsules that starts at nearly 24mm diameter and quickly curves down to 20mm diameter to match the pre-amp body ? I guessing I'd have to make my own, which I don't know if I can do.

Same thing with the AKG's, although a bit easier since it's the same diameter all the way through.
However does the outriggers have to be omni with spheres ? Or depending or the room and what you're recording, cardioïd capsules by themselves as outriggers can work fine sonically ? (on the SE300B in total I have two CK92 and 93, and three CK91).

Also, I wondering about some variant, like if for exemple recording in a very reverberant space, like in our old cathedrals were perharps the reflections are a bit too much with omnis ? And instead use a cardioïd Decca tree, and use additionnal mics off axis to record the room (like a miror pair from a Fukada tree), with maybe two bi-directionnal off by 90° spaced two meters and much father and fairly high (like a Hamasaki square but with only two firgure 8 since it's only stereo)

Get the Heigh/Dunkerley/Rogers book and read it and you will see that the Decca tree and all the other variations on it were developed by trial and error, and you can see many of the other other variations used. I'm not a fan of the Decca tree and certainly I think we have far better choices in overly reverberant environments (and even worse, environments with bad-sounding reverberation) but the book will show you what the Decca people tried and what worked for them.

Don't take it as gospel, but take it as a list of things that people tested and liked given the microphones they had at the time.
--scott

Yeah I've seen it online, the "Classical Recording: A Practical Guide in the Decca Tradition", I wondered about it so I'll definitely give it a shot.

Thanks Scott.

Yes, the APEs will have to be DIY, but it's actually not that difficult; they can be made with hardwood drawer pulls available on Amazon and many craft/hobby stores, with holes drilled with Forstner bits. For the MK012 you drill a hole large enough for the front of the capsule half-way through, then finish the rest of the hole with a bit the diameter of the body. Any gap can be filled with thin craft foam, felt, or even Blu-Tak, plumber's putty, etc.

Decca did use SDC cardioids on a few early sessions, most notably the famous Wagner 'Ring' cycle; in that particular case, KM 56 on the tree, but still M 50 for the outriggers.

https://www.amazon.com/Unfinished-Ki...TXBsSMyqa&th=1

A bit surprised by that choice, I thaught wood would impact the highs and midrange too much compared to the sort of resin they use, like with DPA's APEs.
So it sounds good even with wood balls ?
(I'm assuming diffrent type of wood will impact the frequencies, so pine is good or there's other species that works too ?)

And for the AKG Blue Line, so you say I'll need to drill small vents around the wooden ball, matching the alignment with the CK92 capsule slits ?
(the Oktava omni capsule also has openings at the back, but it's less impacting ? so no side holes ?)

Josephson Engineering used to make APEs, and they were originally made of hardwood; I've used hardwood DIY APEs on the MK012 omni many times; works fine.

I don't know about the CK92; as I said, I don't know why the side vents are there, and I don't know how (or if) they would be affected by an APE.

The Oktava omni has no openings at the back; the slits serve no purpose on the omnis; they just use the same housing on all the capsules. If you look into the rear of the capsule you'll see it looks completely different from the card or hypercard capsules.

The wood used for most drawer/cabinet pulls is not pine; it's a hardwood, probably poplar.

DIY APEs is another reason to get the 'Decca book'; it has some tips on this in the back of it (as well as info on actual dimensions of a Decca Tree, and how to mix and pan the three mics).

Wood is fine; it's small enough that any body resonances are going to be way above hearing. But you might want something harder than pine just because you will drop them.

And the omni capsule will not have any rear vents to block... that is what makes it omni. If it had rear vents, it would become directional. I don't know what those vents on the side of the CK-92 are for... try blocking them while listening and seeing what happens. It's possible they are just for pressure equalization.
--scott

Most people will use wood spheres, as they are relatively easy to source….and you can then spray the outer surface with an epoxy or acrylic paint which will dry to a hard shiny surface of the colour of your choice. You can use alternate materials for the spheres, such as hard acrylic plastic, Delrin….or even track down wholesalers of billiard/8 ball suppliers. Keep in mind the acrylic/Delrin materials will be more difficult to drill….as they will soften or melt with the heat generated by the spinning bit.

One tiny point:

Wood can be heavier than you think, so tighten those mic clips.

Luckly for me the Oktava shock mount (SM-20) can't be adjusted... So maybe I'll use cine shock mounts (Rycote, Cinela, Radius) for them.
That or use paper/painter tape around the body to be just a little bit thicker and bite on the SM-20 better once it's up in the tree.

Blu Tack is the official Decca solution for a tight fitting APE ball. (See book)

As OM-1 is Tapered, this was way easier than boring at angles from Derlin.

Gaff tape is designed for this. Some people use blu-tack to make sure it can't possibly rattle, but gaff tape is good stuff and you should always have a few rolls on hand. I don't know why the stuff is so common in the US and almost unknown in Europe because it sticks and doesn't leave residue.
--scott

Oh ! we have this in france it's another brand that is famous famous for that, however it's usually yellow or white, it's called "Patafix"

Patafix is similar to blu tak although blu tak doesn't leave any residue and patafix can.

Gaffer's tape is like panzer tape /duct tape/ ruban a conduit / but it doesn't leave goo behind like panzer tape does.
--scott

Okay good to know about that Blu-tak paste.
For the gaff tape yeah I know them pretty well, I'm coming from a cinema background, we use all kinda of gaffer tapes, I know the ones that leaves nothing behind an sticks well.