EAW BH-800-LR User manual

Applications
These sound reproducers are designed to provide high
level sound of up to + 125 dB SPL covering the frequency range
from the deepest bass up to the fundamentals of voice and most
instruments. Ideal applications include live concert sound
reinforcement, motion picture and performing arts theaters, and
discotheque installations.
EAW professional sound reproducers are designed with
portability paramount. Their high strength-to-weight ratio makes
them the products of choice among discriminating traveling
companies where ease of set-up and tear-down are important
considerations. Complete road hardware includes skids, handles,
steel corner reinforcements, scuff-resistant black polyurethane
finish, and Tee nuts for the attachment of user selected casters.
Description
BH-800-LR Bass
HornThis bent horn reproducer was designed to eliminate the
compromises in performance that plague most of the folded or
straight designs currently favored by competitors. Using a specially
developed proprietary thin laminated birch hardwood, EAW
developed a horn with a complex expansion characteristic in two
dimensions to achieve a truly exponential flare rate in the critical
throat region. This throat is constructed as a sub-assembly and all
voids are filled with a set-in-place polyurethane foam that provides
maximum wall stiffness while damping any incipient resonances in
the structure.
The horn portion of the reproducer uses a very low
flare rate of 44 Hz and exceptionally large mouth (effectivelythe
entire frontal area of the cabinet) for excellent deep bass response.
The horn is constructed of 18 plies-to-the-inch
crossgrained-laminated Baltic birch hardwood with the highest
stiffness-to-weight ratio of any wood product available. The
resulting product sets a new standard for smooth, deep bass
response at high sound pressure levels. The BH-800-LR will
outperform direct radiating and scoop-type horns in the range
below 250 Hz and exhibits higher conversion efficiency and lower
effective frequency response.
MR- 102-LR Mid-Bass
Reproducer
This exponential horn provides high output at low
distortion throughout the critical mid band that contains fundamental
voice energy, and is typically the weakest link in previous horn
loaded systems.
The MR- 102-LR is an exponential horn with a 175 Hz
cut-off frequency at the lower limit and a maximum operating
frequency of 1,600 Hz.
A proprietary center displacement plug maintains the
exponential expansion rate throughout the throat region. This plug
allows a proper throat cross-section to optimize the smoothness of
response over the full frequency bandwidth of the horn. A side
benefit of this design is that the plug reduces throat size with a
corresponding increase in efficiency. The plug also blocks any
spurious high-frequency spikes from the driver's dust cap from
entering the horn.
Frequency response of the MR-102-LR is driver
dependent, and although the horn exhibits a useful passband of 175
to 1,600 Hz, crossover points of 200 and 1,200 Hz are
suggested for best combination of efficiency (typically 3 to 6 dB
better than most horn-loaded systems), low distortion, and
headroom. The use of the MR-102-LR eases the load on the
midrange compression driver by raising the system crossover
frequency from the 600-800 Hz range to 1,200 Hz, where the
mid-range unit experiences less diaphragm travel. Mid-range
diaphragm replacement is dramatically reduced, and frequently
eliminated altogether, in systems where the MR-102LR is used as the
mid-bass component.
Driver
Complement
EAW reproducers are normally supplied, and function
most effectively, with the EAW/RCF drivers designed for them.
Each EAW product is designed as an integrated system, and the
selection of values and dimensions for cone materials, dust cap,
adhesives and damping materials, voice coil and magnet structure
are carefully calculated to produce the best overall performance of
the system.The LF-301-R driver used in the MR-102-LR has been
special lly tailored with damping compounds to reduce break-up
modes above piston range and to permit optimally smooth
response to over 1,200 Hz. This damping eliminates the high-Q
spikes present in most popular 12" drivers, and makes the
MR-102-LR much smoother in the transition region than other
mid/bass cone systems.
The LF-440-R driver used in the BH-800-LR uses an
18" diameter curvilinear cone supported by a treated linen
sur

round. Its free air resonance is comfortably below the
lowest frequency it is called upon to reproduce, and its
thermal design is correspondingly conservative, allowing a
continuous sine wave power rating of 150 watts continuous,
and 300 watts on program.
Both drivers share a massive magnetic structure
that generates a 14,500 Gauss field in the air gap, and a unique
bifilar wound voice coil minimizes non-linearity at the
maximum excursion. Both drivers share a moderately high
electrical efficiency that allows 107 dB SPL power output at
one meter distance with one watt input.
These drivers are not merely upgraded PA drivers
but are engineered from the frame upward to perform
reliably at high SPLs in their respective applications. They are
virtually indestructible, and their field failure record is
essentially zero when operated within their ratings.
Specifications BH-800-LR MR-102-LR
When loaded with LF-440-R LF-301-R
EAW driver
Nominal frequency 50-300 Hz 150-1, 500 Hz
range ±3dB ±3dB
Suggested operating 50-250 Hz 200-1,200 Hz
range
Acoustical output at
one meter, 107 dB SPL 107 dB SPL
one watt input
Power handling
capacity
Continuous sine wave 150 w RMS 150 w RMS
Program 300 w RMS 300 w RMS
Dispersion
Horizontal 1000 900
Vertical 500 400
Horn flare rate 44 Hz 175 Hz
Cabinet material 18 plies per inch,
cross- grained- laminated birch
hardwood; all voids filled with
high damping factor
polyurethane foam.
Cabinet finish Catalyzed black polyurethane
Cabinet hardware Recessed carrying handles,
steel corners and feet, Tee nuts
to mount users choice of
casters, perforated steel -
protective grilles over drivers.
Input connectors
Standard Dual 1/4 " phone jacks, banana
plugs
Optional Heavy duty Jones type barrier
strips, or blank panel to accept
users choice of terminals
Cabinet dimensions 1.5mH x 0.75mW x 0.75mD
(601/2"H x 293/4"W x
293/4"D)
Weight, with driver 91 kg (200 1 bs.) 50 kg (110
l
bs.)