From: Rob Danielson <>
> m-s in parabs? This was this recommended on this site? An omni or
> omni pair is most common in the diy parab rigs. A couple more
> 62/P6s? For the same money as the MS-957, maybe a Shure MX-183 omni
> lavalier for the parab? There's a model of this mic that comes with 9
> volt battery power (The head/cable can also use the Trubitt/Dugan
> modification to run on plug in power but its a small project). Use
> two for stereo in the parab, but this is more controversial. There's
> a long string on this.
If I remember right the thread that resulted in the MS-957
recommendation may have thought it was for stereo without a parabola.
Personally, all other issues aside, the MS-957 is a bit heavy to hang
out in front of a parabola. And since it's using a directional mid, it
would have to point at the dish, setting it even farther out, a longer
lever arm twisting the wrist trying to hold the rig up.
There's nothing fundamentally wrong with M/S in a parabola, it's been
done, and has been mentioned before. The biggest problem is finding a
light enough mic combo. It has the added advantage that the mid mic
diaphragm can be centered in the axis, not true for other stereo setups.
So it would mix to mono without trouble. The same advantage M/S has
everywhere.
When you move into stereo with a omni pair, you effectively amplify the
mic separation. Probably by a variable amount depending on frequency,
not sure there. So you will end up recording stereo with spaced omni's.
Which don't often mix to mono reliably. Omni's may be a pretty useful
mic for mono parabolics, I'm not near so sure they are all that
wonderful for stereo. Needs a lot more experimentation.
I consider a parabolic that cannot be used in hand to be at quite a
handicap. Thus paying attention to weight and balance.
> They are quite different. the 957 has ~25dB(A) noise if I recall
> correctly. Also lower output compared to your 62 or an MX-183.
> Any value of 10dB (A) and lower in the mic could be considered "low
> noise" under most conditions. Values between 10 and 20 can be more
> than adequate for many applications. You don't mention your
> recorder/mic pre arrangement-- often a limiting factor in overall
> noise produced. Also whether phantom power is a possibility? For
> comparison, an MX-183 is ~ 21dB(A) noise with slightly higher output
> than the me-62. Low noise, small condenser, omni's are expensive. See
> MKH-20. Maybe a CAD M-179 would work (large, heavy)? Both mics need
> phantom power. Allways on the lookout for low noise, cheap, omnis,
The CAD M-179 would definitely win the weight on lever war with your
wrist. And remember it's a mono mic, has to be paired with something for
stereo. My wrists hurt just thinking about a pair out in front of a
parabola.
Note as far as needed self noise that a parabola is providing
considerable gain before the mic. So, a mic standing free would need to
have considerable less self noise than one in the parabola for the same
conditions. All depends on just what you are doing as to how much less.
If getting into stereo parabolics where you are recording direct
ambiance as well as the dish gain you might have to have just as quiet a
mic. For mono parabolics you can cheat quite a bit on self noise.
In early discussions in this group, barely acceptable low noise started
below 20dBA, with values below 15dBA down to 10dBA being much more
desirable. In those early discussions, no mics below 10dBA were
discussed. Values below 10dBA were not available in the full range of
mic designs, should probably more be considered super low. Even now most
such mics don't have a lot of testing in nature recording for their
suitability. I have not found conditions where the 10dBA mics in my
collection were not more than quiet enough. Such conditions can exist,
but they are rare.
It should be noted I don't try and drag way distant subjects in by
amplification. I move through my mic setups on the basis of their
abilities to pick up distant subjects without excessive amplification.
That, of course, leads to my big gun in distance being the Telinga
stereo parabolic. Or trying to get closer so other mics can be used.
If you consistently try to force more distance (or fainter subjects,
same thing) out of your mic's by large amounts of amplification, you
will need lower self noise mics than I use.
Note that mic sensitivity also enters into this, as it is part of what
dictates the amplification.
Walt
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