Meyer Sound HD-1 User Manual
HD-1
The HD-1 High Definition
Audio Monitor* is a self-contained,
precision loudspeaker for nearfield sound reproduction.
Aligned to closely approximate
a true point source radiator, the
HD-1 features exceptionally broad
directivity characteristics. Its time
delay response is tightly controlled,
with minimal deviation from linear
phase across the full frequency
range of its operation. Each unit is
individually factory-calibrated to
ensure unprecedented consistency
of performance. The HD-1 is
suitable for critical applications
ranging from professional recording to psychoacoustical research.
The HD-1 is a two-way system
comprising an 8-inch cone lowfrequency driver and dome tweeter
housed in a vented cabinet. The
low-frequency driver features an
exceptionally large magnet structure and a 2-inch voice coil for
greatest efficiency and heat dissipation. The tweeter employs a
specially-developed impregnated
silk dome to minimize breakup and
colorization.
Both drivers are of a proprietary
design, and are individually
selected for maximum linearity.
Their magnet structures employ
sophisticated field-cancelling
design techniques to minimize
magnetic field leakage, and the
cabinets may safely be placed
High Definition
Audio Monitor
within 2 feet of sensitive color
video monitors. For applications
requiring closer proximity to
monitors, an optional steelshielded model is available.
The HD-1 incorporates line-level
control electronics mounted within
a rear-panel chassis, including:
• an active balanced input circuit
with switchable sensitivity
(+4 dBu or -10 dBV);
• an active crossover utilizing
optimized pole-zero filter
combinations to achieve acousti-
cal transparency and linear
phase;
• independent protection circuits
for each loudspeaker driver;
• dual power amplifiers for
biamplification.
The driver protection circuits
employ thermo-predictive limiters
and soft peak clamps to guard
Operating Instructions
against damage from excessive
amplifier power and ensure
graceful overload characteristics.
Independent power biamplifiers
maximize system headroom,
efficiency and damping while
minimizing distortion. The low
frequency amplifier delivers 150
watts output power, while the high
frequency amplifier provides 75
watts. Both employ complementary
power MOSFET output stages
operating class A at low-to-moderate listening levels (<90 dB SPL),
and class AB at high levels.
The HD-1’s free-field frequency
response is flat within ±1 dB from
40 Hz to 20 kHz (-3 dB at 32 Hz
and 22 kHz). It delivers high peak
SPL with >100 dB dynamic range
and extremely low distortion.
Covers are included for use during
transport.
* patents pending
Meyer Sound Laboratories, Inc.
2832 San Pablo Avenue
Berkeley, California 94702
Setup & Operation
High
Definition
Audio
HD-1
Monitor
Locations of HD-1 Loudspeaker Components, Connectors and Controls
Dome tweeter
Cone low frequency driver
Indicator LED
IEC mains connector
and power switch
Voltage selector
switch
Calibration port
(factory use
only)
Voltage selection and
40
2
0
2
2
0
2
1
0
0
1
PUSH
fuse rating chart
Input connector
Input sensitivity
switch
Impact indicator
Power
• Set the voltage selector switch
before you connect and operate
the unit.
The HD-1 accepts AC voltages
from 90 to 260 VAC, at 50 or 60 Hz,
in four ranges. Select the range that
is closest to the local mains AC
voltage.
Do not switch among AC voltage
ranges with the power cable
connected to an outlet.
Fuse
The HD-1 is protected by a fast-
acting fuse in the voltage selector
switch.
• If the fuse blows, check the line
voltage and the voltage selector
setting.
• Always replace the fuse
with a component of
the same type and
rating.
Power Cable
• Connect the HD-1 to a
three-prong outlet.
Earth ground
Chassis ground
The HD-1 requires a grounded
outlet. Use a grounding adapter
when connecting to ungrounded
outlets.
Blue =
Neutral
Yellow/Green =
Earth Ground (Chassis)
Brown =
Hot
AC cable color code for wiring
international or special-purpose
power connectors
Placement
The HD-1 is designed for “near
field” operation. The best listening
distance is between 3 and 9 feet
from the speaker face.
The HD-1 is aligned for flat
frequency response in free field (no
adjacent boundary surfaces).
Placing it next to a wall or on the
floor will cause the low frequencies
to be exaggerated.
Nearby surfaces (such as a
mixing console control surface)
should be angled to minimize
reflections toward the listener.
For stereo playback systems,
speaker stands are highly recommended. Place them at least 3 feet
from any wall. In recording studios
the speakers may be placed on the
meter bridge.
When handling the
HD-1, avoid touching or
pressing on the dome
tweeter. If the dome
becomes dented, the
unit should be returned
for testing and
calibration
dome pops back into
position.
even if the
If the power cable appears frayed
or broken, replace it immediately
before operating the unit.
2
Never use ground-lifting
adapters. Do not cut the
AC cable ground pin.
• Always allow at least 6 inches
clearance behind the speaker for
cooling airflow.
Loading...