Microphones: the colours on the audio engineer’s palette. Garish metaphors
aside, there’s a great deal of importance resting on the kind of microphone you
choose and where you put it. And let’s be honest, the options are almost
endless. From new Chinese cheapies to expensive and rare vintage specimens,
it can take virtually a lifetime to learn which microphone to use for which
application.

But that’s half the fun. Any serious audio professional, if they’re honest, can
immediately be reduced to a giddy child in a candy store at the idea of giving a
new microphone a whirl. It’s what gets us audio guys going and is part of the
eternal journey of discovery and rediscovery.

Of course, there will always be the tried and trusted mainstays. Models like
U47, U67, U87, RE20, SM57, 421 mkii, C12 and a host of others come to mind.
These are the standards that engineers have come to love and respect; we
know what they sound like and we know what to expect when we use them.
But every now and again new contenders step into the otherwise snobbish
microphone world and cause a stir because they’re just too good to ignore or
because they do things just a little bit differently to what we’re used to.

Earthworks, while not a new brand, is not a prominent brand in South Africa.
This may be because people aren’t that aware of their local presence or it may
be a price issue, but nonetheless, they are serious microphones that deserve
attention and possibly even a little love because if doing things differently is a
mechanism to pique curiosity, then they certainly have my attention.

Sound Harmonics, our local Earthworks distributor, was kind enough to lend us
five Earthworks models on offer for this review: the DK25/R DrumKit-series
recording bundle that includes two omni TC25s, a cardioid SR25 and Earthworks’
innovative KickPad, which supplies instant kick drum-focussed EQ; a cardioid
DP30/C snare/tom microphone and their new hypercardioid SR40V handheld
vocal microphone. We took these mics to Pan Music recording studio in Jukskei
Park, Johannesburg to put them through their paces. But before we get to all of
that, a bit of history is in order.

A little history, a little philosophy

Earthworks, founded by dbx noise reduction pioneer and dbx founder David E
Blackmer in the late 1980s, was originally focussed on designing and
manufacturing audiophile-grade loudspeakers. During their development,
Blackmer realised that the standard measurement tools he was using were
insufficient and that to achieve the level of quality he was aiming for, a more
accurate tool was required. This tool was a measurement-grade omnidirectional
microphone: the QM1, his first model.

This caused his colleagues encourage him to shift his design to other
microphones and preamplifiers, which is the core business of Earthworks today.
However, in spite of this, Blackmer finally produced the Sigma 6.2, his audiophile
dream realised; hand crafted and finished in cherry wood.

Blackmer’s philosophy and research has always been centred on ultrasonics in
sound reproduction. He firmly believes that, despite the mainstream view that
the human ear cannot respond to frequencies above 20kHz, the time resolution
of human hearing is five microseconds or better which corresponds to around
200kHz. Of course, his claim is not that humans can hear linearly up to 200kHz
but rather that extended frequency response and accurate time-domain
performance are crucial to three-dimensional, life-like audio. To quote
Earthworks: This is the motivation behind the design of Earthworks
microphones.

The models

All current Earthworks microphones contain a number in their model number
denoting the upper frequency response limit. For instance, the SR40V has an
upper limit of 40kHz while the TC25 extends to 25kHz. This is central to the
sonic integrity of Earthworks microphones and embodies Blackmer’s philosophy
around ultrasonics. To achieve this, all Earthworks microphones are fitted with
very small diaphragms roughly 5mm in diameter, which also contributes to their
very fast and accurate transient response.

Resultantly, the specifications for all Earthworks microphones are quite
impressive. The omnidirectional TC25 has a frequency response of 9Hz to
25kHz; a max acoustic input of a massive 150dB SPL and has an equivalent
noise rating of 27dB SPL (A-weighted). The cardioid SR25 has a frequency
response of 50Hz to 25kHz, has a max acoustic input of 145dB SPL and an
equivalent noise rating of 22dB SPL. As you can see, these mics have very wide
frequency responses not typical to “regular’ drum kit microphone sets, very high-
level handling and are super quiet.

Both the TC25 and the SR25 have a wider end, where the XLR connector is
inserted and the phantom-powered preamp sections are contained and then
narrow into a shaft around 8mm wide. The SR25 features a few slit-like ports on
its address end, which, I assume supplies its cardioid pattern. Their overall
shape gives them a “measurement mic look’. I couldn’t find any information on
what material they are crafted from but from the looks of it, it could either be
stainless steel or polished aluminium.

The DP30/C is a gooseneck microphone with a right angle head designed, with
the aid of a special clamp, to be fixed to the side of a drum. It looks somewhat
like a lectern microphone, but this is because its clamp is designed to attach to
the bottom rim, which allows the mic to extend above the top rim due to its
length.

The DP30/C has equally impressive specs. It exhibits a frequency response of
30Hz to 30kHz (±2dB at 15cm), a max acoustic input of 145dB SPL and an
equivalent self-noise of 22dB SPL.

The hypercardioid SR40V is a high-end vocal microphone aimed at the live
market and is one of the newer additions to the Earthworks family. Finished in
flat black and crafted from stainless steel, it has all the hallmarks of a live
microphone and, disregarding the inverted teardrop ports at the base of the
grille, it looks somewhat like a Shure SM87 with its flat-top address end.

However, the difference is under the hood. Designed to deliver flat performance
when the mic is 15cm from the source, the foam-covered capsule also measures
around 5mm, just like Earthworks’ other microphones. The SR40V features a
frequency response of 30Hz to 40kHz, has a max acoustic input of 145dB SPL
and has an equivalent self-noise of 22dB SPL. This is extremely quiet for a live
application microphone.

The tests

First we tested the DK25/R bundle with the KickPad and the DP30/C on the
drums. I would love to say that this was a comparative review but since we
didn’t have anything in our mic locker that was similar in design, we opted to
just set them up and take a listen. The TC25s were placed in a spaced
configuration, equidistant to the snare drum while the SR25 was placed just
inside the hole in the front head of the kit. The DP30/C was positioned to pick
up the snare drum.

I’ve always been intrigued by minimal drum mic setups. Indeed, Glyn Johns is
famous for his three-mic technique and recently Eric Valentine demonstrated a
one-mic technique for achieving Motown sounds. This is not something I
typically go for as these days it’s most common to use a combination of close
and distant microphones but this gave us a chance to see what could be
achieved.

At first we listened to the overheads. The TC25s supplied a very transparent
sound and captured a lot of the room due to their omnidirectional response.
This could be a hurdle for some studios that have less-than-good sounding live
rooms. In that case it may be beneficial to go for the DK25/L cardioid bundle.
However, since the angled ceiling in the live room at Pan Music starts at 9 feet
and extends to about 15 feet, and the room is largely asymmetrical, we thought
we got a very true and faithful image of the kit with just the right amount of
room tone.

Adding in the SR25, we were presented with a thuddy, chesty kick sound that
didn’t sound tailored or “pillowy’ at all. At first I wasn’t happy with the sound I
was hearing so I moved the microphone a little further inside the kick drum hole
to accentuate the low end a bit more and get a bit more attack. I then flipped
the polarity on the overheads and suddenly the kick drum came to life.

Overall the kit sounded good. I could see how experimenting with various
three-mic techniques might yield different results but if you’re doing a jazz
recording or a style that requires a very live and flat sound, the three mics will
probably work out perfectly for you.

Adding the DP30/C I was instantly impressed with the snare sound we achieved
without any EQ. It had just the right amount of top end, the attack was
fantastic and it had ample body and punch. I became an instant fan of the
DP30/C and it added the perfect amount of cut and punch that the snare drum
was begging me for.

Moving our attention to the SR40V we figured that given that the specs of the
mic were comparable to studio mics, we should compare it to our Manley
Reference Red studio condenser and, funnily enough, a plain old SM57. We
wanted to hear if the microphone truly brought studio quality sound to the
stage. Accordingly, we set all three mics up in the vocal booth and local rap
artist Prozaktly sang and switched between them from six inches away.

The Manley, of course, exhibited a classic large diaphragm studio condenser
sound. It had a silky top end, a smooth midrange and big bottoms. By
comparison, the SR40V, surprisingly given its extended frequency response,
sounded darker and more rugged. This was not what I expected. This may
have been because the Manley could be somewhat hyped in the low and top
end, but I definitely got the impression the SR40V was flatter and therefore
sounded a little boxier in comparison. Switching to the SM57, we were surprised
to hear a bit more clarity in the top end. However, the SM57 did not take well to
plosives and performed terribly off-axis, which the SR40V handled with ease.

The wrap

Earthworks make beautiful microphones. If a hyped sound is what you’re after,
do not look here because, as their literature states, their goal is a flat and
extended frequency response. For this reason transparency is the name of their
game and is why, after some more experimentation, their mics respond
wonderfully to EQ and exhibit near perfect polar patterns that do in fact remain
even across all frequency and position within the pattern. They are, all in all,
truly remarkable microphones.