Recording - March 2015 - 38

B Y PA U L V N U K J R .

Sonodyne
SRP 400 Active Monitors
Great sound comes to small spaces

Sonodyne is an audio company based
in India with a 40-year history in the business, one that's just beginning to attract
serious attention here in the USA. The
designers and engineers at Sonodyne do
everything in-house, from initial concepts
to industrial design, prototyping, sourcing
and manufacturing.
Sonodyne's full line includes products for
the home hi-fi market, commercial installs,
and the pro audio industry. Its pro monitor
lines are the SM Series and the SRP Series
(plus the SLF subwoofers). The SM Series is
the upper line with six models, while the
more budget-oriented SRP Series currently
has 4 models to choose from. In a review
in our February 2013 issue, Lorenz
Ryncher found the SM200Ak to be "powerful, balanced, and honest to the ears."
This month we take our first look at the SRP
line with the SRP 400. The SRP line, aside
from the very smallest SRP 300, has quite similar design and build; models are available
with 3.5", 4.5", 5", 6", and 8" woofers.
With its 4.5" woofer, the SRP 400 is one of
the "babies" of the SRP Series, intended for
small and intimate listening spaces.
Heavy metal and curves
Each model of the SRP line starts with a
pressure die-cast aluminum enclosure.
The SRP 400 measures 9.13" x 6.3" x
6.1" and weighs 9.7 lbs. It is dense, rigid
and heavy for its size, which is a good
38

RECORDING March 2015

quality for a speaker to have. The SRP
400 rests on 4 small rubber loose-fitting
feet, that allow the speaker a nominal bit
of float and decoupling. These feet,
which are prone to falling out, were one
of my only construction gripes with these
monitors; Sonodyne informs us that this
has been corrected and improved on current units.
The 1" silk dome tweeter sits inside a
waveguide that is molded into the cabinet
and designed to minimize reflections for a
wider and more honest soundstage.
Moving to the woofer, while the upper end
models make use of woven kevlar, the SRP
400 features a 4.5" CURV cone. CURV is a
woven, self-reinforced polypropylene material with excellent internal damping, manufactured by Norwegian company Seas. At
the bottom of the box is a front-firing aerodynamic bass port.
Internally the SRP 400 is biamplified;
each driver has a 25 Watt amplifier, and
the crossover frequency is 3 kHz. It has a
frequency response of 75 Hz to 22 kHz (±2
dB) and a maximum peak SPL of 100 dB.
On the front of the cabinet is a power
switch with blue LED power light, as well
as a volume knob that controls output
level from muted to +6 dB, with a 0 dB
center detent. On the back of the unit are
4 equalization DIP switches. The first is a
Bass Roll Off (100 Hz, 6 dB/octave).
Then there are two Bass Tilt switches,

which can be used separately or together
for -2, -4, or -6 dB of shelving at 100
Hz. The last switch is a -2 dB Treble Tilt
at 4 kHz. XLR and 1/4" TRS input connectors, a 1/4" TRS Link connection to connect
the other half of a stereo pair of speakers
in a daisy-chain, and an IEC power cable
socket complete the back.
In use
I spent a few weeks with the SRP 400
monitors, first using them as a second set of
small reference monitors in my studio, The
Moss Garden. I then moved them to my
office at Grace Church, where I work as the
Technical Director and do a huge amount
of podcast audio work-mixing the musical
portion of Sunday Services as well as
voiceovers for videos. Finally, I took them
home to my small and cozy music listening
room/edit suite. This speaks to the first big
plus of the SRP 400: they are highly
portable and make a great traveling speaker if you have such a need.
In my studio, which is a fully treated and
trapped mix room, I put them up alongside
my usual KRK E8b monitors-not for comparison's sake, but because I always like to
have a set of smaller secondary monitors to
aid me in my mixes and give me more of a
sense of real-world listening.
Since my KRKs are a good distance
back and wide in the listening field, putting
the SRP 400s beside them was not the
most optimal positioning. While these
speakers can get nice and loud, their low
end was quickly swallowed up in this
space. Their mids and highs do sit very
nicely, however, and were great for seating vocals and mid-forward guitar tones in

Recording - March 2015

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