Meyer Sound Self-Powered Loudspeaker HM-1 Specifications

FEATURES
Bi-amplified
Integrated electronics
Dual-concentric drivers
Full-range response
R
(42Hz - 20kHz)
Phase corrected to 15 kHz
15
kHZ
U
Magnetically shielded
48 VDC powered
48
VDC
Superior
engineering
for the art
and science
of sound.
Meyer
Sound
HM-1
Self-Powered Loudspeaker
The Meyer Sound HM-1 is a
very compact, full-range self-
powered loudspeaker system
designed to serve in a wide
variety of installed sound
reinforcement and repro-
duction applications.
The HM-1 incorporates
significant design innovations
that afford unprecedented
performance with practical
advantages. In contrast to
conventional small speaker
systems, the cabinet venting is
tuned at 40 Hz to provide flat,
full-range response with half-
space loading. The concentric
tweeter mounting structure is
optimized to minimize both
back-wave interference and IM
distortion. A constant-
directivity high-frequency horn
affords a 100 beam width, and
sophisticated phase-correction
circuitry assures true point-
source performance without
the off-axis cancellation effects
that plague customary dual-
concentric designs.
By implementing distributed
amplification, the HM-1 affords
substantial advantages in
reliability and ease of
installation when compared
with constant-voltage (70 V)
distributed systems. The HM-1
accepts a unipolar 48 VDC
power source which may be
supplied using twisted-pair
wiring jacketed with the signal
source conductors, eliminating
the need for wiring conduits
and greatly reducing induced
noise. Its amplifier and signal-
processing circuits are
designed to tolerate supply
voltage drops of up to 15%,
accommodating light-gauge
cables and long cable runs.
Internal energy storage circuits
minimize the system's peak-to-
average supply current
demands, allowing efficient
use of switched-mode
regulated supplies.
The HM-1 is a two-way
system comprising a 7"
graphite cone low-frequency
driver, and a concentrically-
mounted 1" soft-dome high
frequency driver with constant-
directivity horn, in a vented
cabinet. Integral bi-amplifiers
affording 400 Watts total
power output are built into the
enclosure, along with an active
crossover, driver protection
voltage limiters, and frequency
and phase response alignment
circuitry. A laser-trimmed
differential input stage affords
superior common-mode
PATENT PENDING
rejection to accommodate
simple twisted-pair signal
distribution. Front-panel LEDs
indicate power, signal limit,
and thermal overload, and
a rear-panel circuit breaker
provides overall DC
power protection.
The magnetically shielded
HM-1 enclosure is coated with
a textured black or white
finish, and a variety of factory-
installed mounting config-
urations may be ordered.
Optional accessories include a
remote switched-mode power
supply, a variable-speed
cooling fan assembly
controlled from an integral
rear-panel drive output, and an
auxiliary subwoofer that
provides flat response to 42 Hz
in free field and is powered by
the HM-1 low-frequency