I agree with your experiences and would love to have a week's
workshop somewhere, trying to find a "formula" which we would all put
our names under.
(I'm not being ironical, it only sounds that way)
I have never succeeded in getting good "headphone-stereo" with omnis,
without having something in between.
And too far apart, you get a hole in the middle.
There is, however, (an old Schoeps design??) which has been built and
modified and which converts distance (between mic's) to amplitude in
the way you want it to.
A friend of mine has made a very compact "almost omni" A-B stereo
setup which fits really well into "normal" spaced home-loudspeakers,
even though the distance between mic's is only 130 mm. You can
regulate the stereo width on location, analog, - or in post
production. I'm not sure if one can find a digital software doing the same=
.
The 4 capsule array / channel are omnis, but together with the pipe
surface they are facing out of, they get some horizontal
directionality at higher frequencies, while cutting some hf vertically..
Using his omnis on location, the users have very little wind and
handling noise problems, still they get a full-stereo which fits very
well into a common studio monitor pair. The linearity is almost
extreme and there is no "crisp" at higher mid. His mic has been
successfully used for the most demanding on location musical
performances. The noise level is around 18 dB(A) though, which is a
little too much for naturesound.
The Schoeps design with two omnis facing out of a globe takes a lot
of qualified design work. My own attempts to copy the Schoeps head
have all failed in that I get a poor forward.
Another way to experiment, is to use omnis facing towards a ball or
pipe surface, using the PZM effect. That is not A-B stereo, though.
Klas.
At 13:00 2007-05-10, you wrote:
>Klas Strandberg wrote: "I think A-B stereo always have to be judged
>from how it is replayed."
>
>Good point, Klas. So...
>
>Let's assume I am asking for both - what spacings work best for
>headphones, and what spacings work best for speakers?
>
>I have found that closer spacings seem to work well for headphone
>listening, particularly (and unsurprisingly) 17cm or so. But when
>played through speakers this spacing tends to create a boring and
>narrow stereo image that is clustered around the middle, with not much
>side information.
>
>Wider spacings of 25cm or more work well for speakers, but are harder
>to judge over headphones in the field because, at the widths that work
>well for speakers, there is often a hole-in-the-middle effect on
>headphones.
>
>In the case of speakers, let's assume the speakers and listener are
>set-up in the 60 degree equilateral triangle often recommended for
>stereo monitoring.
>
>Any suggestions, anecdotes or links to nature recordings made with
>spaced omnis would be appreciated. :-)
>
>- Greg Simmons
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email:
website: www.telinga.com
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