Recording - October 2021 - 14

A Family of Microphones Compared
The Shure Unidyne... or, The SM57 & Friends
SM57
Shure SM57; $99
The Shure SM57 is a cardioid (unidirectional)
moving coil (dynamic) microphone
with a transformer output. It measures
6.34 " x 1.68 " and weighs .63
lbs. The SM57 is finished in a dark gray
enamel, with a polycarbonate grille /
surround housing the capsule behind a
stainless steel windscreen.
The SM57 has a significant low-end
rolloff from 200 Hz down to 40 Hz, an
even midrange from 200 Hz to 2 kHz
with a shallow dip from 200 to 600
Hz followed by a prominent presence
peak beginning at 2 kHz and climbing
to +6dB at 6 kHz before rolling off in
stages down to 15 kHz.
Thanks to
its upper-midrange presence,
the SM57 has found much use as
a first call instrument microphone over
the years, commonly shoved into the
grille of a screaming guitar amp or capturing
the thwacks of snare drum, toms
and percussion. The controlled low-end,
coupled with a wonderful proximity
effect, plus its forward presence, have
also made it popular on kick drum, bass
cabinet, acoustic guitar, etc.
This proximity effect and directionality
have also made the SM57 a popular
vocal mic, alongside and even in place
of the SM58.
14 RECORDING October 2021
While many modern dynamic microphones
are trending brighter and chasing
a condenser-like sound, I often wonder
how I would describe the SM57 if it
were brand new today. I would probably
call it smooth, rounded and punchy.
I might even use the word vintage. That's
just speculation, of course, as it's impossible
to divorce oneself from the fact that
the SM57 is the sound of electric guitar
and snare drum on zillions of popular
recordings over the past five decades,
not to mention vocals.
SM stands for Studio Microphone,
and in essence, it was designed as
the studio version of the Model 545
Unidyne III. You will often hear people
say that you should have at least one,
or even three or four on hand in your
studio at all times, and they are correct;
in fact, reviewer and drummer David
Blascoe has six that he uses exclusively
to record his drums for clients, including
using them as overheads.
The SM57 is one of the toughest-
darn near indestructible-mics of all
time. Having said that, its weak point
is the polycarbonate capsule cover.
They can become loose, crack and fall
off. The only downside I have ever had
when using a road-worn SM57 as a
hand-held vocal mic is that it can introduce
a click or two into the proceedings
if the cap is loose. Luckily, replacement
grilles are readily available.
The SM57 is the common link to every
mic in this roundup, and with only two
exceptions, they all share the same (Unidyne
III) capsule (or a slight variation).
Shure SM58; $99
The Shure SM58 is a cardioid, handheld
dynamic microphone measuring
6.3 " x 2 " and weighing .66 lbs. It's
finished in a dark gray enamel, with a
large 2 " nickel ball-style grille, and an
internal foam blast filter.
The SM58 has a rounded low-end
rolloff from 125 Hz down, a generally
even midrange from 125 Hz to 2 kHz,
with a slight dip at 4.5 kHz followed by
a broad 4-5dB presence peak from 2.5
kHz to 7 kHz, along with a second 5dB
peak from 8 kHz to 10 kHz, followed by
a sharp cutoff.
The SM58 is one of the most used vocal
microphones of all time, even more
so live than in the studio. Thousands of
famous live recordings have been made
with this mic.
Despite utilizing the same capsule as
the SM57, with a different resonator
disc the SM58 has a broader, less pointed
upper-midrange presence boost and
a touch more low-end extension, despite
it not having the same proximity effect of
the SM57; most of this is due to its larger
round grille, which keeps the source
farther away from the capsule.
Primarily used as a hand-held mic,
it is largely immune to handling noise,
thanks to an internal pneumatic shockmount
(also in the SM57), and it's even
more rugged than its 57 sibling. Note,
the grille is easily replaceable if it should
get dented, which does happen.
While the SM57 sees regular use on
instruments and vocals, I rarely see the
SM58 used on instruments unless it is
subbing for an SM57 shortage. This is
a shame, as its extra blast protection
and slightly fuller low-end make it an
even better choice on kick drum in my
opinion, and it can also sound quite
nice on acoustic guitar and brass instruments;
the SM58 is quite popular
SM58
Recording - October 2021

Table of Contents for the Digital Edition of Recording - October 2021
