Recording - May 2013 - 35

What’s inside stays out of the way
The AT5040 is a transformerless design
with a pair of matching linear amplifier
circuits which use all-discrete components
and through-hole circuit board design.
Each circuit feeds two of the diaphragms,
and since the power load is spread out
between the two it results in a lower operating noise floor.
Also worth noting: there is no equalization present in either circuit. All of the
sound and tuning of the mic happens at
the capsule level. Similarly, the mic features no pads, filters, switches or added
functions of any kind—again, think purity.
Specs and graphs
The AT5040 has a fixed cardioid polar
pattern, a 20 – 20,000 Hz frequency
response, an open circuit sensitivity of
–25 dB (56.2 mV) re 1V at 1 Pa, a 50
ohm impedance, a max SPL of 142 dB, a
self-noise level of a mere 5 dBA, and 137
dB dynamic range. As is commonly the
case with high-end electret condenser
mics, it still requires 48V phantom power
to operate.
Looking at its frequency graph, three
areas jump out: a low-end bump between
20 and 80 Hz, a strong mid rise from 1.5
to 4 kHz, and a smaller high-end plateau
from 8 to just above 10 kHz. All of this,
particularly the pronounced mid peak, fits
perfectly in line with this mic’s intended use
as a vocal mic. While it does have a touch
of 10 kHz sparkle, it is nowhere near as
bright as many modern condensers that sit
high in the 8 to 15 kHz range.
In the sweet spot
A rectangular diaphragm has the
advantage of an extremely linear off-axis
response, and this is one of the first things
I noticed about the AT5040. Moving from
the rear and around the mic, its off-axis
rejection is smooth and linear but equally
pronounced and quick.
This gives the AT5040 a very narrow
sweet spot. The upside of this is a very
focused and present sound devoid of
extraneous noise and sonic clutter in the
soundfield; the downside is that a singer
must remain in said sweet spot, making
this mic a tad troublesome for those
singers who like to bob and weave to the
music.
When other sources are positioned offaxis this mic is very successful at ignoring
them, making this a great choice for those
who like to track live with a band in one
room as well as for those who prefer to
track while listening to monitor speakers
and not use headphones. Yes, there is
some bleed, but I found the volume of the
off-axis source to drop 60 to 70% in volume, ending up roughly equal to much of
the overly loud headphone bleed that
often creeps into vocal tracking sessions... in other words, manageable.
RECORDING May 2013

Plosives, pops and spits
The AT5040 is a very clean and clear
mic, and it has a strong output. On loud
instruments and even some very loud
singers, I would recommend an inline pad
or a mic pre/console with a pad that is
pre input rather than post; otherwise clipping of your mic preamps could occur.
Interestingly I found that despite this
microphone’s low bass bump which lives
in a range we typically filter out, the
AT5040 does not have as strong a lowend proximity effect as I was expecting. I
found I had to get right up on the mic with
lips almost on the grille to get a deep
chesty DJ or Barry White tone.
In my tracking sessions, I did find that
the mic was quite prone to popped “P’s”

and “S’s”; I found the ensuing effect similar to what you’ll get from many classic
small-diaphragm mics like the Neumann
KM84 or the Shure SM81, where a blast
of breath can cause the signal in the mic’s
head amp to clip and “fart out” for a second. This problem is easily solved with
even a cheap nylon pop filter, but it is still
something to be aware of when using the
AT5040.
A sound all its own
So with the technicalities and practicalities behind us, it’s time to ask: how does it
sound? I have over a dozen different largediaphragm mic flavors in my collection,
including mics large and small, costly and
relatively affordable, from companies like

http://www.gracedesign.com

Recording - May 2013

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