> Could you tell me more about how you choose an angle, or what
> happens when you change it?
Niki,
And thanks for the compliment. Theoreticlly two gunmics should not
give a good stereo "picture" but they do, and that's where practice
wins over theory.
The theory says that with any two directional mics set for stereo,
front sounds should be 6dB down and equal. If they are too wide, you
get a hole in the middle, and too narrow reduces the stereo image.
The theoretical problem is that all directional mics, especially
gunmics, have a very variable frequency response off-axis, so with my
MKH-416 pair I settled on 40 degrees for the best sound. I tested this
with "walkaround" recordings and a peanut shaking test as on my
website. Controversially I use the idea of "sonels" or sound pixels to
describe identifiable points on a stereo image and thus, equal points
on the walkaround test should be matched by even sonels in the stereo
image.
> Have you ever set up your mics above the ground,
Yes. When I was recording profesionally, mics went on mic stands
because that is what they are for. But when shooting drama outdoors,
you sometimes need to get a mic close but not visible for effects, so
I tried laying it on the ground, hidden by tufts of grass or
whatever, and surprise surprise, it often sounded better down there.
There are other advantages such as less wind and lower background
noise and they don't blow over. If it doesn't sound OK, use a mic
stand, but low mounting is needed for a mic tent.
The reason for using a tent is so that I don't have to rush out in the
middle of the night if it starts raining to fetch the mics in. This
used to inhibit my recording habits, as they are often on long cables
in the woods. I discovered that my MKH's survive well in a tent in all
weathers and they have been out for months.
The tent also reduces the side and rear pickup, but the main problem
is wind flapping the tent, so I use an old bedspread to try to damp
that down. The upside is that the cables come into my bedroom so I can
lie in bed and choose what to record.
Getting back to stereo pairs, I've tried an MKH-416 with an MKH-816
long gunmic and still got reasonable stereo. To someone who didn't
know the setup, it would sound good. Matched mics is a good idea but
exact matching of an identical pair is nonsense because, as above, the
off-axis response is all over the place anyway and the only way they
would match is by pointing in the same direction which would not be
stereo. Manufacturers won't give off axis responses, otherwise nobody
would buy their mics. :-)
The benefit of using gunmics is that sound from above, below and all
around the back is reduced in volume, so giving a cleaner stereo image
than any other type of stereo rig, and well worth the compromises. And
also the pair gives good ambient sound images including woodland
reverb.
David
David Brinicombe
North Devon, UK
Cogito cogito ergo cogito sum - Ambrose Bierce
|