Is there anything resembling a formula or basic guidelines for sizing
a Decca tree? I know the proportions (2X from left to right, 1.5X
from front to back) as described in the New Stereo Soundbook: but can
the overall scale be related to the size of the facility somehow?
What guidelines would someone use when designing a tree assembly? Is
there a smallest practical size or could I rig up 3 Schoeps mini mics
into a palm-sized tree? Seriously, what are the tradeoffs for smaller
vs larger and could the size be somehow related to how live/dead the
room is, or ???

steve

hollywood_steve wrote:
Is there anything resembling a formula or basic guidelines for sizing
a Decca tree? I know the proportions (2X from left to right, 1.5X
from front to back) as described in the New Stereo Soundbook: but can
the overall scale be related to the size of the facility somehow?

Not really. It relates to the size of the stereo image you want, and
the directionality of the microphones. The standard proportions are
about right for M50s.

What guidelines would someone use when designing a tree assembly? Is
there a smallest practical size or could I rig up 3 Schoeps mini mics
into a palm-sized tree?

I don't think you can do Decca miking with something as omnidirectional
as the Schoeps. The whole point of the system is that it takes advantage
of the top end directionality of a large diaphragm omni.

Seriously, what are the tradeoffs for smaller
vs larger and could the size be somehow related to how live/dead the
room is, or ???

The more you pull them apart and toe them out, the more separation you
get and the wider the image there is. If everything is clustered in the
center, pull them apart. If there's a hole in the middle, move them together.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

"Scott Dorsey" wrote in message
...

I don't think you can do Decca miking with something as omnidirectional
as the Schoeps. The whole point of the system is that it takes advantage
of the top end directionality of a large diaphragm omni.


I agree with this assessment to a point. I've used B&K 4006s in a decca
tree and wasn't thrilled with the result. I've used Schoeps but with the
MK21 capsules and had pretty good luck there. I like them as they tend to
approximate the response of an M50...

While I haven't personally tried it, there are also folks that will drill
out balls to put on the outside of the capsule and get good results that
way...

--Ben

--
Benjamin Maas
Fifth Circle Audio
Los Angeles, CA
http://www.fifthcircle.com

Is there anything resembling a formula or basic guidelines for sizing
a Decca tree? I know the proportions (2X from left to right, 1.5X
from front to back) as described in the New Stereo Soundbook: but can
the overall scale be related to the size of the facility somehow?

The Decca tree was designed for orchestras. You can scale it down when working
with smaller ensembles. Some of the best imaging I've ever heard on Kronos was
a smaller Decca tree arrangement set up for a film scoring date they did at
Todd-AO. Direct to room ratio was incredible. I'm sure there's a point where
downscaling the tree makes it stop working & the imaging falls apart, & I
suspect that point will be determined by the pattern of the mics you use.

The standard proportions are
about right for M50s.

Bobby Fernandez, an ace Hollywood orchestral sound track engineer, told me he's
converted from M50s to Sennheiser MKH20s. Says he gets the same overall sound,
but with a lot less self-noise.

I don't think you can do Decca miking with something as omnidirectional
as the Schoeps. The whole point of the system is that it takes advantage
of the top end directionality of a large diaphragm omni.

It may be a stretch to even use the term "Decca tree" in this context, but I
heard a system using Coles 4038s in a tree arrangement for the PBS "Sessions"
series. Sounded very good, but was really a bit more like 3 spot mics over the
band than a coherent stereo image. Might have worked better if they were pulled
in together more, but this is a preset flown overhead arrangement, a sort of
one size fits all thing for that show.




Scott Fraser