Boston Acoustics LYNNFIELD VR-M50 User manual

LYNNFIELD VR-M50 AND VR-M60
Refer
ence Quality Monitor Loudspeakers
New Product Announcement
The VR-M50 and VR-M60 are compact, monitor-quality
speakers designed to deliver accurate, natural repro-
duction with an elegant appearance.
Special care has been taken to optimize the speakers’
components for maximum performance: The bass units
utilize die-cast aluminum baskets which keep the criti-
cal moving parts in precise alignment for exceptionally
accurate response. The cast baskets also conduct heat
awayfromthe voice coil, increasingpowerhandlingand
maximizing output. The woofer cones and surround ge-
ometry were designed and optimized with Boston’s
Finite Element Analysis (FEA) computer modeling tech-
nology, for strong bass and smooth midrange.
High frequencies are handled by Boston’s exclusive
1-inch (25mm) aluminum tweeter with Amplitude Modi-
fication Device (AMD). This remarkable driver produces
an extremely smooth, flat response well beyond the
audible range. A die-cast aluminum heatsink attached
to the tweeter’s backplate dissipates heat quickly and
efficiently, assuring cool, trouble-free operation, even at
very high power levels.
The drivers are positioned very closely to each other for
smooth, uniform radiation in both the horizontal and
verticalplanes.Thecabinetfeaturesheavyinternal“win-
dow-pane” bracing for strength and rigidity, minimizing
cabinetresonances. The rear-mounted vent is smoothly
flared at both ends to reduce port turbulence, and both
speakers feature dual gold-plated binding posts, allow-
ing bi-wiring or bi-amping with virtually any cable.
All the drive units are designed at Boston’s Peabody,
Massachusetts facility using state-of-the-art computer-
design programs and are built in Boston on proprietary
production lines to an incredible ±1dB—perhaps the
industry’s tightest tolerance. Both systems feature
MagnaGuard®magnetic shielding for compatibility with
home theater systems.

Specifications subject to change without notice. DCD is a trademark and Boston, Boston Acoustics, and MagnaGuard
are registered trademarks of Boston Acoustics © 1999 Boston Acoustics, Inc.
300 Jubilee Drive Peabody, MA 01960 978-538-5000 Fax: [phone]
Specifications VR-M60 VR-M50
FREQUENCY RESPONSE (±3dB) 51-20,000Hz 59-20,000Hz
RECOMMENDED AMPLIFIER POWER 15-200 watts 15-150 watts
NOMINAL IMPEDANCE 8 ohms 8 ohms
SENSITIVITY (1 watt [2.83v] at 1m) 90dB 89dB
BASS UNIT 61/2" (165mm) DCD™ (Deep Channel Design) 51/4" (135mm) copolymer
TWEETER 1" (25mm) black anodized aluminum dome 1" (25mm) black anodized aluminum dome
CROSSOVER FREQUENCY 2500Hz 2700Hz
DIMENSIONS (H x W x D) 113/4 x 85/16 x 117/8" (299 x 212 x 303mm) 97/8 x 71/8x 9" (251 x 181 x 230mm)
WEIGHT 17 lbs (8kg) 12 lbs (5.5kg)
FINISH Cherry or black ash wood veneer Cherry or black ash wood veneer
with gloss gray top panel with gloss gray top panel
Lynnfield VR Tweeter with
Amplitude Modification Device
Our sophisticated VR tweeter may be the smoothest, most accurate
high-frequency driver available today. We use a 1-inch (25mm) dome
made from anodized pure aluminum. We chose anodized pure
aluminum for the diaphragm for several reasons: Compared
to a soft dome, aluminum is equally light and more rigid;
the added stiffness improves off-axis dispersion and
consequently the total radiated power above 12kHz.
Compared to other hard dome materials such as titanium,
phenolic, and polycarbonate, our pure aluminum dome has
a resonance beyond the audible range (25kHz) and is far
better damped. This tweeter is unrivaled in its ability
to accurately track the input signal.
To further optimize the tweeter’s response, we
use our patented Amplitude Modification Device
(AMD). The AMD is an innovative acoustic tuning
device, positioned in front of the aluminum dome.
It consists of five miniature ducts of slightly varying
lengths precisely tuned to create an extremely smooth
response. Their tuning is so critical, manufacturing is done to watchmak-
ers standards—the tweeter's AMD is accurate to ±.001 inch (.025mm)!
Ferrofluid-cooled voice coil
Acoustic damping
High-energy neodymium magnet
Die-cast aluminum heatsink
Faceplate with integral AMD
Surround
1-inch (25mm) anodized aluminum dome
Voice coil carrier
Terminal
Low carbon steel top plate
Yoke
Tweeter response
without AMD
Boston's AMD
creates smooth,
natural response
The port is precisely flared
at both ends to minimize
audible turbulence.
Dual gold-plated binding
posts allow bi-amp/bi-wire
connections for optimum
performance.
1kHz 10kHz 20kHz 40kHz
0 dB
+5 dB
-5 dB
1kHz 10kHz 20kHz 40kHz
0 dB
+5 dB
-5 dB