Sweet Monitors Tickle My Ears
The DynAudio Acoustics BM15A
ã 1998 by Eddie Ciletti
I’ve been listening to the same speakers for ten years. Back in the
day — when everyone else was complaining about NS-10s — I chose the Electro-Voice
MS-802 because it complimented my preference for extended bass and non-abrasive
TO BOLDLY GO…
In recent years, however, the challenge of reviewing equipment (comparing
digital audio converters, for example) has created an ever-increasing need
to hear more detail. In addition, using a Soundscape workstation has greatly
expanded my ability to create precise, intricate and sophisticated mixes.
These two applications alone have changed the way I listen. Short of riding
the shuttle into space, I needed a monitoring system that would boldly
take me into new sonic territory.
I am familiar with the current batch of popular monitors, but as
in the past, that did not dissuade me from auditioning something different:
the DynAudio Acoustics BM15A. This bi-amplified system consists of an 9.5-inch
woofer and a one-inch tweeter in a ported cabinet that is 17.4h x 10.75w
x 13.5d. A rear panel switch selects operating level, +4 or -10. Input
is via XLR connector.
Foam plugs are provided if you prefer non-ported operation. The same
package is also available as a non-powered version, model BM15. Left and
right cabinets have the drivers arranged as a mirror image, a good thing
for a symmetry freak like me.
DEVELOPING A RELATIONSHIP
Mixing and mastering is an "ongoing" process; hence this is not a
review but rather an "interactive evaluation." After mixing four songs
and pre-mastering two CDs, all within a three-month period, I am not ashamed
to say that relations with the BM15A’s have been "intimate."
Both the Dynaudio and EV monitors have a similar cabinet volume yielding
a bass output within the same ballpark (with the port open). The similarity
ends there, however, because the BM15A delivers greater tightness and precision
from the crossover point (2.5 kHz) on down. (Plugging the port will further
tighten the bottom.) I definitely needed more low-end clarity. Since the
EV is "soft" sounding, the resulting mixes often had too much mid-range
punch when played on other systems.
I sit close to the monitors — about three feet, plus or minus six
inches. At that distance, I don’t need much output from the tweeter. On
the rear panel, Dynaudio have provided both Bass and Treble pots. Switches
would have been preferred for precision and repeatability, but since the
range is limited to plus and minus 3 dB, I did not consider this to be
a problem. I ran the bass flat and the treble at minimum (-3dB). This concurred
with the EV HF level control, which has been living at –4 dB.
The difference in treble response between the two monitors was more
divergent than at the opposite end of the spectrum. The BM15A is clearly
the winner — delivering an extended high-frequency range, with greater
detail and more openness (or "air") without harshness. The EV tweeter has
a "schmeer" between 5kHz and 10kHz that makes things "seem" brighter yet
the lack of response at frequencies above this range robs not only detail
but awareness of noise as well.
One feature in particular increased my fondness for the Dynaudio
BM15A. It has no sweet "spot." The lack of phase interaction between the
woofer and tweeter allows the engineer, producer and client a fairly similar
listening experience. By contrast, the EV has a much narrower range; a
little vertical movement — standing up, for example — can make the MS-802
sound completely different.
I was already familiar with Dynaudio because their speaker components
are used in audiophile monitors such as the Duntech "Sovereign" and "Black
Knight" series. (One of the reasons for their popularity is unit-to-unit
consistency.) The Dynaudio BM15A has more in common with these towering
behemoths than the typical near-field monitor. Better monitors have more
"self" control and therefore less coloration. The BM15A is simply a better
CUP OF TEA
I think it’s fascinating that monitoring systems generate such radically
polarized opinions. For example, Genelec lovers hate Meyer and vice versa.
Both are well crafted and similarly priced products, but if neither is
your cup of tea, check out the Dynaudio’s BM15A. It’s for those who are
looking for something else!
SIDEBAR: Loudspeaker Concepts
Self-powered monitors are a very "nineties" phenomenon but this trend
is neither superficial nor hype. The concept of minimizing cable length
between amp and speaker makes perfect sense, especially for low frequencies.
If short is better than long, then why not have almost none? Locating the
amp inside the speaker cabinet, the choice of esoteric or generic speaker
cable is no longer an option. (Think of the money you’ll save!)
Another weak link between amp and speaker is the passive crossover
network. Splitting the audio spectrum for woofer and tweeter is a necessary
evil, but the passive approach is more costly and more difficult to get
right than its active counterpart. Bi-amplification puts the crossover
the amplifier, improving efficiency and allowing more precise control over
each frequency band.
The edge of the woofer in the BM15A has a "surround" made of long-life
Neoprene instead of "foam" which disintegrates over time. The voice coil
is made of ultra-light hex-shaped aluminum wire rather than copper. The
decreased mass of the high-excursion coil increases linearity — especially
at higher levels — lowering overall distortion.
One could argue for either a ported or an "air tight" cabinet. One
is more efficient while the other is perhaps a bit more precise. The foam
plug provides an option that is different from turning down the bass because
it affects low frequency resonance just before roll-off begins.
Little is mentioned in the product literature about the dome tweeter.
From previous experience I had learned that Dynaudio use ferro-fluid,
which improves efficiency by closing the gap between magnet and voice coil.
By allowing heat to dissipate via the same path helps to maintain greater
accuracy even after repeated doses of high-level, potentially damaging
with questions and recipes.
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