Microtech Gefell M 930, August 2000

CARDIOID MICROPHONE
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The sheer number of inexpensive, large-diaphragm cardioidcondenser mics now available makes it hard to
choose one, and the clamor caused by $500-and-under mics has risen to
such a peak that large-diaphragm cardioid condensers like the Microtech
Gefell M 930 ($795) tend to get lost. That's a shame because Gefell has
been making quality mics for quite a while, and this one is no
exception.

When I reviewed the Microtech Gefell M71 (the "Perestroika" mic) in
November 1991, I said that for $995, it was a low-cost alternative to
Neumann, with an arguable link to the Neumann lineage. G Prime (then
Gotham), had made arrangements with Microtech Gefell of East Germany to
distribute three microphones-the UM 70S ($1,150), UM 70 ($995) and M 71
($795)-that were originally designed by Georg Neumann, were based on
the M7 capsule and had been unavailable because the company was behind
the Iron Curtain. Based on the success of those first offerings, G
Prime has continued to distribute Gefell microphones that, not
surprisingly, sound quite a bit like Neumanns.

The design of the M 930 is also based on the M7 capsule. Unlike the
double-sided UM 70 Series, the M 930 is a single-sided capsule with one
gold-sputtered membrane. The circuitry and capsule have been modified
so that they remain shock-mounted in very little space. The mic is only
4.5 inches from tip to base, which makes it quite nice for getting into
small spaces. It is remarkable for several other reasons. Its
self-noise is a very modest 7 dBA. Its sensitivity is 21 mV/Pa, and its
max SPL for 0.5% THD is 142 dB. Like the UM 70 Series Gefell mics, the M 930
employs a wedge-shaped head grille, although it is more truncated than
the UM Series.

Oddly, the company logo has been placed on the back of the capsule.
The body is made of steel and covered by multiple layers of
electroplated finish: copper, a satin nickel finish, and then an
optional bronze finish. The logo and model number are actually
laser-etched into the bronze, allowing the lower layer of finish to
show through.

THE SOUND
Using a pair of GML mic pre's, I found that my Gefell M 71 was about 10
dB less sensitive than the M 930. The M 71 also had audibly more
self-noise. After adjusting for equal loudness, the frequency response

curve of the M 71 had a bit more edge on the upper midrange and was
perhaps slightly thicker in the upper bass. Maybe the thing for putting
a nice edge on a voice track or muted instrument, but perhaps a bit too
edgy for a horn part or an electric guitar cabinet-depending on the
arrangement and intent, of course.

The fuller sound of the M 930 fell in line with G Prime's notes that
showed the company had made this mic to have a fuller sound based on
user requests. A quick look at the frequency response charts shows that
while the bottom of the UM Series starts to roll off at 500 Hz and is
down over 4 dB at 50 Hz, the M 930 doesn't start to fade until 200 Hz
and is only 2 dB down at 50 Hz. on the top end, the M 71 hump is in the
4 to 11kHz range, while the M 930 hump is in the 6 to 16kHz range. In
layman's terms the M 930 has less self-noise, more output, more sizzle,
more thump.

I put the M 930 up against a Neumann TLM 103. At a distance of
several inches or less, the mics sound remarkably similar. Their
self-noise and sensitivity were virtually identical. The M 930 has
slightly more bottom and top, the TLM 103 a slight preference for the
midrange, but slight movements and changes due to proximity effect made the differences difficult to
detect. Both mics are equally prone to popping.

At a distance of two feet in a semi-damped acoustical environment,
the M 930 had about four inches more reach. After I engaged a 75Hz
18dB/octave highpass filter, the reaches equaled out and the
TLM 103 sounded slightly bigger than the M 930, a characteristic
experienced as a slight thickness in the upper bass or lower
midrange.

The cardioid patterns of both mics are practically identical, a
generous 150 to 160 degrees, with very minor off-axis coloration,
fairly tight nulls at the 90-degree marks and similar-sounding rear
lobes. Sound entering the top of the head grilles was also very similar
and not particularly ugly.

The TLM 103 is better isolated from external vibration and handling
noise. The Neumann spider mount suspension is also more effective than
the optional Gefell EH 93 suspension mount for the M 930. As a result,
thumps to the mic booms were much more noticeable through the M
930.

IN CONCLUSION
The Gefell M 930 is a microphone you can sing into, speak into or put
on an instrument or amp. Like most large-capsule condensers, it does
have a noticeable proximity effect. It has a natural sound. It's not
sparkly with lots of air, or particularly fat or thick. It's just
there, and with a nice presence lift. If used in percussive
environments, a better suspension mount might be needed. The M 940 hypercardioid and M 990 vacuum tube version of the
M 930 are also available.

One final note: I was never able to get inside the mic to see the
actual board layout, capsule and suspension parts because there was no
obvious way to gain access. The seam between the body and the head
grille implies that the head grille is either clamped or screwed on.
After giving it a good twist didn't work, I gave up.

Microtech Gefell GmbH, www.gefell-mics.com