KM 183 - Recommendations and guidance please

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Ken, mostly I use Schoeps nowadays, but in the mid-1970s I recorded
classical and baroque music with KM 83 microphones quite a bit--often
in stone churches with the usual wooden furnishings but sometimes also
in large concert halls. The KM 183 is the same capsule with more modern
electronics; its sound is essentially the same as the KM 83. Both
microphones have an excellent low end and midrange, but the high
frequencies are emphasized to a degree that is sometimes just too much.

You can, of course, fix that with EQ, and anyway it depends on the hall
and the type of placement that you use. But if you don't trim the
treble a few dB, you are pretty much forced to use a distinctly distant
placement unless you want to be smacked by that high end.

The diffuse-field response of this type of microphone is roughly flat,
but due to its size (small, but still "large" in terms of physics,
relative to the very short wavelengths of the highest audio
frequencies) a considerable high-frequency rise inevitably occurs on
axis. This type of capsule has flat response only when the microphones
are placed so far back in a hall that the dominance of reflected sound
over direct sound would be quite unusual today--it would probably not
sound very professional in modern terms. That recording approach, and
that type of omni capsule, really made more sense in the mono era when
an entire orchestra/chorus/opera was sometimes picked up by a single
microphone. To get reasonable balance between the closest and the
farthest instruments and/or voices, the microphone would be backed away
quite a distance--farther than one would ever choose for stereo A/B
pickup. Think pre-World-War-II mono records--Telefunken re-issues of
the Concertgebouw orchestra with Mengelberg, etc.

Neumann makes an alternative pressure capsule type with flat response
on axis, but they sell it only as an "active capsule" (AK 31) in their
more expensive, modular KM 100 series--the capsule alone costs 20% more
than an entire KM 183 microphone. And that capsule suffers from the
opposite problem: it sounds right only when used quite close to the
sound source(s) in a hall, where the predominant sound energy is
direct. When placed at the usual distances for A/B stereo miking it
sounds a little dull. Since if you went for that type of capsule you
would almost certainly want to EQ its high end up a little, you might
as well stick with the KM 183.

These two capsule types correspond to the two classic measurement
microphone types (free-field and diffuse-field equalized). But neither
classic type is appropriate for most stereo music recording. What's
needed is either [a] a response characteristic that's laid down between
those two extremes in an intellient way (of which Schoeps offers
several varieties); [b] simple high-frequency EQ of some kind; or [c]
(applicable only in the fantasy world) a dispensation from the laws of
physics which make smaller microphones noisy.

Could you possibly borrow (or rent) a pair of KM 183 and a pair of
Schoeps CMC 62S or 62H to try them out? Or are you comfortably equipped
to EQ most of the recordings that you make with these microphones?
--best regards

Archived from groups: rec.audio.pro (More info?)

In article <41D0E3DE.56C389E5@nowhere.com>,
Ken Lacouture <aint-tellin@nowhere.com> wrote:
>H'okay, the tax man says I gotta spend a little dough on gear before the
>end of the year. I've been in need of a pair of good pressure omni mics
>for a while. Acoustic and classical make up an increasing amount of work
>I'm doing, and I'm feeling like AT 4050's in omni pattern just aren't
>cutting it anymore.

Try the AT4049. It's not a KM100, but it's not bad and it is cheap.

>Has anyone worked with them? Love them, hate them? Wanna talk me out of,
>or in to the idea? Major design flaws I should know about? Should I save
>my pennies for the Schoeps instead? Will I hate the bump at 10k? Should
>I consider the KM 100 series instead? Etcetera?

The KM100 series sounds better, but I don't know why. I would tell you to
save your money for the Schoeps... the omni isn't that much better but the
cardioid is a lot better. And you might want cardioid capsules someday.

The MKH-20 is another thing to look at. It has some lower midrange funniness
compared with the Schoeps, DPA, and Neumann stuff, but it is quieter.

Don't forget to look for used stuff, of course.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Archived from groups: rec.audio.pro (More info?)

<< Also, I'm a bit naive when it comes to the near/free vrs. diffuse field
thing -- where does one end and the other start? >>

The direct field is where direct sound predominates over reflected sound. The
diffuse field is where room ambience takes over & is louder than the direct
sound. Where both are equal is often called the critical distance. The critical
distance is determined by the acoustics unique to each space.


Scott Fraser

Archived from groups: rec.audio.pro (More info?)

Ken, as far as Schoeps omni capsules are concerned, I'd look at the MK
2S and the MK 2H. Which one you would choose is a matter of taste and
also a matter of your preferences for mike placement. The MK 2S is a
little brighter in the free field (i.e. direct, on-axis sound) so it
balances out a little farther from the sound sources than the MK 2H
does, but that also depends a lot on your own sense of what the balance
of high-frequency energy should be in a recording.

Scott Fraser has answered the question about free field vs. diffuse
field very well in practical terms. Theoretically, however, these terms
are extreme opposites.

A diffuse field is one in which the arriving sound energy is randomly
distributed as to the direction from which it is coming. That condition
is only approached, but not reached, in practice. Obviously in a purely
diffuse sound field, there would be no distinct direct sound energy at
all. That's not where any of us would be likely to place microphones
for recording, unless it was as a special effect of some kind--it would
be a very disorienting sonic experience. The closest you get to it in
real life is in certain cathedrals and cathedral-like spaces.

The word "free" as used in "free field" means free from obstructions or
reflecting surfaces. In the free field, all the sound you pick up is
direct. If you went up into they air 1000 feet and recorded a sound
source there with no other objects in the surrounding space, that would
be something like free-field conditions. Again, not like what we
encounter in the typical recording situation (unless your life is very
different from mine).

--best holiday regards