DAN DUGAN:
> > Were they omni mics mounted in the boards? I'm curious about the
>> nature of "too much bass response."
CURT OLSON:
>183s flush-mounted through 1/2" holes in 1x6 pine stock, thus
>incorporating the capsules into a boundary. My seat-of-the-pants
>observation is that this seems to accentuate the the already-ample low
>end of the 183s. I believe mic theory would predict this too, if I
>understand correctly.
Umshankar explained about small boundaries. That's why I asked, too,
because your report was puzzling.
I wonder if you were hearing a reduction in the high end rather than
a boost in the bass. Two possibilities for that, 1) the 183s are
directional at high frequencies (most omnis narrow down at the top
end), and forward sounds are "off axis" to your 110 degree wedge
mount. Or 2) a dip in the hf response caused by how the 183s are
inserted into the board--something that could be tuned out by moving
the mic in and out to find the sweet spot. Just speculating.
>I'll continue beyond the scope of your question. The reason for the
>boundaries is that in my experience, spaced omnis can give terrific
>stereo imaging in an enclosed space with a specific targeted sound
>source, such as a choir or orchestra. But for outdoor ambience, phase
>interaction between the mics makes imaging a mess and destroys mono
>compatibility every time. (I'm talking about close spacing here -- say
>4" - 9" -- that someone can easily carry in the field, not wide
>spacing.)
Same thing happens with an orchestra.
>But when the mics are incorporated into boundary, this phase
>interaction at close distances seems to be virtually eliminated while
>the distinct and desirable omni characteristics seem to be preserved --
>with a little low-end boost thrown in.
I've experimented more with barriers than with boundaries. My
shoulder-mounted 183s face directly forward to focus the hf response,
but they have my neck in between, . Since the mics aren't mounted
right on my neck, it's a barrier rather than a boundary. I don't
worry about mono compatibility.
>I've focused most of my tinkering on learning the effects of boundary,
>size, shape, material, spacing, angles, and positioning of the mics
>relative to the edges of the boundary. The idea is to end up with a
>nice stereo spread that is spacious and also accurate as to sound
>source vectoring. I suppose I could go buy a SASS and be done with it,
>but that would spoil all the fun!
I'm pleased with the stereo perspective in my shoulder recordings,
but I admit I haven't done a formal test of how accurate it actually
is. I should.
-Dan
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