LAB REPORT
24 Australian Hi-Fi ˹˹˹ƖŘˁʊǒǔǞƖƋɁȧ
Newport Test Labs measured the Dynaudio
Evoke 50 loudspeakers using its standard
test procedures. Graph 1 shows a frequen-
cy response that was obtained using two
different techniques. The section of the trace
below 900Hz is the averaged result of nine
individual frequency sweeps measured at a
distance of three metres, with the central grid
point of the microphone on-axis with the
tweeter, so one measurement is made with
the mic aimed directly at the tweeter, anoth-
er with the mic higher, another with it lower,
another with it off to one side, another with
it off to the other, and so on, until nine trac-
es have been acquired, after which they’re
averaged via post-processing. The section of
the trace above 900Hz is the gated high-fre-
quency response of the speaker, without the
grille fitted. As you can see, each of the major
horizontal divisions on the graph represents
a 5dB change in level, so the graph shows
the response of the Dynaudio
Evoke 50 as extending from
35Hz to 22kHz ±3dB, which
is an outstandingly good
result, particularly in terms
of bass extension, for a
design that uses relative-
ly small-diameter bass
drivers and a relatively
small-volume cabinet.
Pedants with sharp eyes
might point out that
the trace is actually a lit-
tle below the –3dB enve-
lope between 42Hz and
52Hz, but the magnitude
of the variation and the
measurement variabilities
at these frequencies mean
that we can safely ignore
this to arrive at the ‘over-
all’ response stated. So
35Hz to 22kHz ±3dB it is.
That said, the response is
not super-flat within these
dB limits, with definite lifts
to above the ‘reference’SPL
(85dB) at around 1kHz (only
minor) and around 3–6kHz
(also minor). NonethelessI
would thus expect the soun
to have a very slight forward
character at these frequencie
LABORATORY
TEST
REPORT
Given that the higher of the two crossover
frequencies is at 3.5kHz, I expect that the
3–6kHz lift is the result of some summing
of the midrange and tweeter outputs, and as
such might not be as apparent when listen-
ing slightly off-axis.
The high-frequency response of the
Dynaudio Evoke 50 is shown in greater detail
in Graph 2, but you should note that the dif-
ferent measurement technique that’s used in
order to provide this detail means that only
high-frequencies can be measured (in this
case, those above 900Hz). The graph shows
the high-frequency response with the speaker
grille off (black trace) and on (red trace).
You can see for yourself that the response
is marginally smoother and more linear
without the grille, though the differences are
barely significant. You can see that for this
trace, taking 95dBSPL as the 0dB reference
point, the response extends from 900Hz to
22kHz ±2.5dB. The low-frequency response
of the Dynaudio Evoke 50 that Newport Test
Labs has shown in Graph 3 shows the output
from the bass-reflex port without any bung
at all (red trace) and with the half-bung
fitted. You can see that without the bung,
peak output is a bit above 40Hz, itself just a
bit above the bass drivers’ minima at 38Hz.
Withthe half-bung fitted, the
utput from the port drops
y 5dB, as you’d expect, and
hepeak output also drops
n frequency down to 32Hz.
The black trace shows the
response of one bass driver
(for clarity) without any
bungs, and you can see
that the response rolls
off quite steeply from
around 60Hz. The blue
trace shows one bass
driver’s response when
the port is fully blocked,
resulting in a sealed
(infinite baffle) enclosure
and you can see that at
60Hz, instead of rolling
off, the response extends
linearly downwards at
around 12dB/octave, as
theory would predict.
Impedance vs. frequen-
cyis shown across three
graphs, rather than just
heusual single graph, due
o the number of permu-
ations permitted by the
rovision of, effectively,
reecompletely different
binet alignments, each
e ofwhich will affect theimpedance (as you can see). There are several
important take-aways from these graphs. The
first is that the impedance of the Dynaudio
Evoke 50 remains at or significantly below 4Ω
from around 75Hz right up to 700Hz, so this
speaker will require your amplifier to deliver
some fairly serious current, as well as voltage.
Secondly although Dynaudio specifies mini-
mum impedance as being 3Ω at 100Hz, New-
port Test Labs shows that minimum imped-
ance of its test sample was a little lower again,
at 2.8Ω (at 100Hz). Lastly, the impedance is
fairly high at very low frequencies, and above
700Hz essentially continues to rise, so the
Dynaudio Evoke 50 should be compatible
with all modern Class-D amplifier designs, as
well as conventional Class-AB designs.
Graph 7 shows the performance of both
bass drivers and the midrange driver. You can
see that although the bass drivers are identi-
cal, their different positions on the front baf-
fle mean their performance is not identical.
It’s almost the same up to 400Hz after which
the response of the upper-most driver rolls off
quite dramatically to trough at 550Hz before
rising. I expect this is most likely a result of
a standing wave inside the cabinet. It’s inter-
esting, but at this frequency the midrange
driver has well and truly taken over deliver-
ing the sound, as you can see from the green
trace. This driver has a flat response, and its
response rolls off nicely above and below its
passband. Excellent design.
Newport Test Labs measured the sensitivity
of the Dynaudio Evoke 50 as being 87dBSPL
at one metre, for a 2.83Veq input under
its standard test conditions, a result that is
in exact agreement with Dynaudio’s own
specification.
Dynaudio’s Evoke 50 loudspeakers re-
turned an excellent set of results in Newport
Test Labs’ acoustic test laboratory, and is no-
table for havinga particularly-well-extended
bass response. Steven Holdingyd
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onDynaudio’s Evoke 50
loudspeakers returned
an excellent set of test
results in Newport
Test Labs’ acoustic test
laboratory