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-   -   Decca tree outdoors ?? (http://www.dvinfo.net/forum/all-things-audio/526035-decca-tree-outdoors.html)

Bob Hart December 10th, 2014 06:27 AM

Decca tree outdoors ??
I am doing a pro-bono video this coming weekend of a Carols by Candlelight ( actually LED prettylights because of fire bans ).

There will be a stage and sound assistance for the audience by way of typical stage speakers. I will be unlikely to be able to source a feed from the mixer.

Because I already have the Decca tree arrangement made and am fairly familiar with its behaviour, I had a notion of parking it on a light stand to hopefully get a blend of the PA stage audio and the live-audience singing the carols. The audio will not be super-critical but it would be nice to get a good stereo finish if I can.

The performance area will be at the bottom of a natural ampitheatre with a hill backdrop behind a small lake.

There is a very slight echo return off the backdrop, a sort of nice ambience.

The vexed question is, will I be on a hiding to nowhere with the Decca tree? Any traps, suggestions on position. Rather than being over the announcer's podium and front of stage, I intend to place it to favour the audience and run an independent two channel source into the second camera as a safety.

The same choir will be performing as in this clip. The location will be about 200 metres down the gully.

Bob Hart December 10th, 2014 06:31 AM

Re: Decca tree outdoors ??
The lower ampitheatre is visible in the backdrop behind the Turkish guitar player in this clip. The audience will be picnic sat on the slope at left, the performers on the more level area on the right near the small lake.

Paul R Johnson December 10th, 2014 06:46 AM

Re: Decca tree outdoors ??
I've never thought of using this technique outside, but I can't really see any reason not to, and for this kind of thing, it might be rather a neat idea! All that would worry me was physically getting it up in the air and keeping it there. It's a big beast for a light stand set on it's highest setting - and surely a bit top heavy and unstable?

Gary Nattrass December 10th, 2014 09:38 AM

Re: Decca tree outdoors ??
Hmmm not sure if it will work very well outdoors as the idea is that the decca tree gives a sense of the auditorium that it is placed in.

I would have thought a central M/S mic outputting A+B would be a better choice or a central AT875R with two other AT875R left and right to sort of give a directional decca tree?

Bob Hart December 10th, 2014 10:21 AM

Re: Decca tree outdoors ??
Paul and Gary.

Thank you for your prompt responses.


The affair I have built was light. It originally stood on a yellow workshop light stand. It will go up on a telescopic lamp stand designed for heavier 2K or 1.2K HMI lights. I will criss-cross a couple of fence pickets into the ground and tension down onto them which should take care of any tendency to topple over.

The arms will be three graphite boom poles in partial extension with proper mounts for the mikes compared to the modified mop heads I made arms from for the symphonic performance I last used a Decca tree to record.


My kit consists of three Rode NT2a mikes, a pair of Sony mikes similar to NTG2 except of a narrower directional field and a couple of older Sony C74 directionals, which are somewhere between the Sennheiser 416 and 816 in their pickup pattern.

The sloping auditorium as such is confined at the rear of audience by a steep bank of about 1.5M (6ft) and then a steep slope heavily studded by high trees which from ground to about 5M are mainly hard trunks. There is a faint echo return comes back off them. The same goes for the very steep slope on the opposite side of the watercourse and the pool which is about 20M across at its widest and about 100M long.

The gully crosses right to left with the left side being signficantly lower and expected to soak up loose sound more that the right side does. The right side gully is canyoney with granite faces and quite live.

The ambience is somewhat unique, which hopefully I can try to capture.

The audio from their PA system was very boomey at the Remembrance ceremony and the prior Tulip Festival. I want to put distance between it and my mikes.

Jay Massengill December 10th, 2014 02:03 PM

Re: Decca tree outdoors ??
I would post an assistant and use some caution tape or small lights on the stand and anything you brace it with.

Never underestimate the ability of someone to simply walk right into your setup, especially in the dark.

Or to have a conversation or cellphone call within the pickup of your mics.

Also hope for very light or no wind!

Good Luck with the project!

Gary Nattrass December 10th, 2014 05:21 PM

Re: Decca tree outdoors ??
If I was doing it I would just have the three NT2a mics as a frontal LCR set-up in from of the choir rather than a central decca tree array.

It may also be interesting to set the L+R mics to fig 8 (or Omni) as that may add some of the stereo ambience to the left and right but still give you a firm mono image from the centre mic.

I have also done similar situations with a sony M/S mic in the centre and two AT875R mics left and right to add extra stereo width to a large choir.

Bob Hart December 11th, 2014 06:48 AM

Re: Decca tree outdoors ??

For the symphonic recording, the L and R mikes were set to figure 8 and the centre mike to omni. It worked quite well. Proper audio engineers would probably be left shaking their heads.

The week prior in the symphonic rehearsal, before I got hold of the Rode mikes, I used one NT2a in omni as the centre mike and the two C74 directionals as the wing mikes. To try to get the nearest thing to figure 8 wth them I tried pointing them over the sides of the orchestra significantly upwards and outwards and use the rear lobes. The result was "interesting". It seemed a little more strident than three NT2a mikes.

As for things being belted to bits, knocked over or just plain stolen, - have been there.

The worst is when somebody stands in front of your camera and for some peculiar perception of civil right, just won't budge.

The second worst is when lone rangering and some clown decides to step over the rope to reset the aperture on the unattended locked off master camera because he thinks "it is a bit dark" and is therefore helping you out.

John Willett December 11th, 2014 07:14 AM

Re: Decca tree outdoors ??
I would be wary if it's a proper Decca Tree.

The microphones used for a Decca Tree are omnis in a ball - Neumann M50 and similar - and all of these have a metal diaphragm.

I know that Neumann say that their metal diaphragm mics should not be used outdoors.

Bruce Watson December 11th, 2014 10:01 AM

Re: Decca tree outdoors ??

Originally Posted by Bob Hart (Post 1870297)
Because I already have the Decca tree arrangement made and am fairly familiar with its behaviour, I had a notion of parking it on a light stand to hopefully get a blend of the PA stage audio and the live-audience singing the carols.

A Decca Tree is a specific solution to a specific problem -- how to record a fully symphony orchestra in an excellent acoustic. The farther you get from this situation, the less well a Decca Tree works. And you're asking about something that's about as far from ideal Decca Tree conditions as is possible.

So no, I would certainly not suggest using a Decca Tree for this duty. Not in any way, shape, or form.

For starters, how will you protect the mics from wind noise? If you're going to be outside, you're going to have wind.

Rather than a Decca Tree, I'd look first to a mid/side or Blumlein pair. In a windshield, which companies like Rode make specifically for this.

Bob Hart December 12th, 2014 09:15 AM

Re: Decca tree outdoors ??
For reasons of practicality and to avoid conflict with the amenity of the outdoors event, my original ambitions have had to be curtailed.

I may not be even able to use tripods, let alone a Decca Tree on a light-stand. The array itself was going to be of a modest size and live incognito in a stiffened beach umbrella canopy with additional fur material if needed.

So it may throw down to Blumlein near the fixed camera, a simple sync mike on the second camera, in-camera mike on the roving EX1, with the omnis staying at home.

Paul R Johnson December 13th, 2014 04:24 AM

Re: Decca tree outdoors ??
Not much point in Blumlein outdoors as there's nothing behind to record is there - apart from aircraft and the birds?

Rick Reineke December 13th, 2014 08:12 AM

Re: Decca tree outdoors ??
+1 Paul. No there's not much point in Blumlein config outdoors. Nor did the OP mention he even had a Figure-8 pattern mic.

Bruce Watson December 13th, 2014 02:23 PM

Re: Decca tree outdoors ??

Originally Posted by Paul R Johnson (Post 1870626)
Not much point in Blumlein outdoors as there's nothing behind to record is there - apart from aircraft and the birds?

And the live audience?

Bob Hart December 13th, 2014 08:31 PM

Re: Decca tree outdoors ??
Much of my problem arises from not being able to access a clean feed from the soundie. The prime objective is to put on the show not make a movie.

That does not really matter although if there is a bit of wind the stage audio is going to float all over the place - real ugly.

My main objective with the Decca Tree was to have it among 1000 or so folk on the hillside singing their hearts out, with the amplified performance relatively distant. The valley makes a natural ampitheater and has a unique acoustic.

Thank you everyone for your helpful suggestions. We shall see how right I get it on the night. Have been slipping behind rebuilding a big old Vinten tripod for the media students to use. It is a beauty. It has spring counterbalance and therefore does not go over like a melted candle and break lenses. So I better get stuck into it.

Three hours to go to rig time.

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