(jnorman) wrote in message . com...
i'm thinking of picking up a couple of LD dynamics for the studio,
after reading the consistently good comments on them from dorsey and
fraser and others. the RE20 and the sennheiser 421 and 441 are seem
pretty nice. which would be the best choice for mainly classical
instruments in a studio setting? violin, cello, oboe, picollo,
various ethnic instruments, etc. how would they do on piano, pedal
harp, or classical guitar? what preamps work well with dynamics like
these? thanks.

What I'm surprised about is that with all the comments, opinions,
ideas and suggestions about what mics to use, no one has brought up
the important issues of transient response and formants. Frequency
range (which many people call "frequency response") is certainly
important, but only in a limited way. For a natural sound on acoustic
instruments, which I think the original poster is looking for, flat
amplitude response in the important band of the frequency range is
probably more important than the ultimate extension. None of these
intstruments produces fundamentals below about 80 Hz (cello) and the
harmonics of most probably don't go above 15kHz (except perhaps for
the piccolo).

But the formants of the instruments are what give them their
distinctive sound. Formants are the fixed sonic "fingerprint" of each,
regardless of what note/s they are playing. So what really makes one
mic more applicable than another for this natural acoustic sound is
usually dependant on the flatness of amplitude response across the
midband frequencies (80 Hz to 10 kHz). Mics designed for "character"
often have significant bumps or dips in the midband, which tends to
distort the formants enough to reduce the overall illusion of realism.
Related to this is the off-axis response eveness in the same frequency
range.

But one other very important criteria is transient response. In a
strange way, it is interrelated to frequency response in that a mic
capable of very good transient response can also be capable of more
extended frequency range at the high end. However, many mics, and
dyanmic mics in particular, use successive resonance points to acheive
good high frequency response, and this destroys accurate transient
reproduction by smearing the information in the resonance areas (i.e.
spreading the information out over time).

But for natural acoustic instruments, perhaps especially something
like classical guitar, transient response itself is very important.
And just by the nature of the physical capsule design, dynamic mics
have much more moving mass and therefore much worse transient response
than do ribbon mics, and to an even greater degree condenser mics
which have the smallest moving mass of the three types.

So, the ideal mic for the purpose described above, IMHO, is a
small-diaphragm condenser mic for these reasons:

1. Good off-axis response across the widest portion of the frequency
range
2. Excellent transient response
3. If well designed, good amplitude linearity across the frequency
range, especially in the critical mid band.
4. If well designed, low self noise (important for single string
instruments, especially classical guitar which has a lower acoustic
output.

There are certainly other choices, and in many cases, certain mics may
work "better" on a particular instrument or to get a particular sound
character. But I don't think any other type of mic will do as well
across the entire range of instruments to get the overall best
results.

Some excellent choices for cardioid pickup (some of which have been
mentioned) a

Neumann KM84 (a classic, and not terribly expensive if you can accept
a used mic and not 100% cosmetics)
Neumann KM184 (a tad brighter)
Schoeps CMC6+MK4 (excellent "realism", a tad bright)
Sennheiser MKH40 (perhaps the most "natural" of the group)
Josephson (I don't know the models very well)(comparable to the KM84)
Wright (are they still around?) (reported to be very good, especially
on classical guitar)

I've also found that the Oktava MC012 is OK, but seems to lack some of
the "grab" of the above mics. Something about the way the transients
sound to my ear, and the way the upper harmonics line up doesn't seem
quite right. But if you're on a tight budget, you could do worse.

There are a couple of mics that can sound very good in limited
applications, but I've found them to have proximity effect that is
tuned to provide linear bass response at much closer distances than
the mics on the above list, and thus aren't as universally useful.
This is especially important with acoustic instruments when you need
to use the mic at a greater distance in order to capture more of the
overall output of those instruments (musical instrument output polar
patterns are quite interesting, I might add).

Thus, these two sound good and may find use but not as often:

DPA4011
Earthworks cardioid mic (can't remember the model number)

Respectfully,

Karl Winkler
Sennheiser

"Karl Winkler" wrote in message

But one other very important criteria is transient response. In a
strange way, it is interrelated to frequency response in that a mic
capable of very good transient response can also be capable of more
extended frequency range at the high end. However, many mics, and
dyanmic mics in particular, use successive resonance points to acheive
good high frequency response, and this destroys accurate transient
reproduction by smearing the information in the resonance areas (i.e.
spreading the information out over time).

Karl Winkler
Sennheiser

Excellent post Karl, in particular this paragraph clears up and explains in
good engineering terms what I've been hearing on some cheaper mics.

Many thanks!
--
John Cafarella
End Of the Road Studio
Melbourne, Australia