Acoustic research ar 11 brochure

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Acoustic Research

Advanced Development Division

AR-11 loudspeaker system

The AR~11 is the most accurate
speaker system ever made by
Acoustic Research. Its per-
formance. drivers. and cross-
over are identical to those of
the AR-lOn. except that the
AR~11 does not incorporate a
Woofer Environmental Control
and the associated crossover
components. The AR-tf is
designed for optimum perform-
ance when placed against a
wall. as on a bookshelf. or
slightly away from two r00m
surfaces. as illustrated.

The AR-lf uses a substantially
improved version of the 305 mm
(12 in) woofer with which
Acoustic Research introduced
the acoustic suspension princi-
ple to home listeners. as well

as the hemispherical dome

midrange of the AFt-3a. it also
uses a newly designed 19 mm
(1/. in) highrange based on the
original high-frequency dome
radiator introduced by Acoustic
Research in 1959. This high-
range driver incorporates new
diaphragm materials. voice
coil. and construction tech-
niques that have produced sig-
nificant improvements in
performance over earlier ver-
sions. It has a lower resonance
frequency and more extended
high-frequency response. plus
greater efficiency and higher
available output.

These drivers are used with a
new crossover network to '
produce a speaker system wrth

uniformly dispersed flat energy
output to the highest audible
frequencies. It is able to trans-
mit the information from a pro-
gram source to listeners in most
locations in a room with an
unprecedented degree of
accuracy.

A pair of three-position switches
provide a means of decreasing
the overall level of the mid
range and highrange drivers in
3dB steps. The 0' position of
the switches should provide
the most accurate results in
most listening rooms. while the
' 3dB and 6dB' settings

are useful for compensating for
the effects of more reverberant.
0r 'live'. rooms.

The AR-ll shares many of the
appearance features of the
AR-tOn. including an easily
removable precision-machined
foam grill. which was chosen
for its near-perfect acoustical
transparency.

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Specifications

Drive units: 305 mm (12 in)
acoustic suspension woofer.
38 mm (1v: in) hemispherical
dome midrange. 19 mm (M in)
hemispherical dome highrange
Crossover frequencies: 525 Hz.
SOOOHz

Impedance: 4 ohms nominal
Controls: Two 3-position
switches for midrange and
highrange level control
Efficiency: 1 watt will produce
86dB SPL on axis at 1 meter
Amplifier power requirement:
Minimum 25 watts per channel
for an average room: to obtain
a closer approximation of the
minimum power required. in
continuous (HMS) watts per
channel for the realistic repro-
duction of musical sound levels
in a particular room. divide the

volume of the listening room.
measured in cubic feet. by 100:
25 watts (into one speaker only)
will produce 100dB SPL in a
3000 cu ft room of average
reflectivity (energy absorption
coefficient of 0.15); 50 watts
(25 watts per channel) will
produce 103dB SPL in the
same room

Power-handling ability: May be
used with amplifiers capable of
delivering up to 150 watts con-
tinuous power per channel
being driven to clipping 10 per-
cent ol the time. on normal
music source material
Crossover network: Hali-
section LC network on each
driver using air-core chokes
and computer grade electro-
lytic capacitors; acoustic out-
put of midrange and highrange

drivers is controlled by switch-
able resistive networks

Driver resonance frequencies:
Wooler 18Hz (free air). mid-
range 400Hz. highrange
2000Hz

System resonance frequency:
42Hz

Effective system O: 0.7

Total flux: Woofer 200,000
maxwells. midrange 70.000
maxwells. highrange 21,000
maxwells

Flux density: Woofer 9.800

gauss. midrange13,000 gauss.

highrange 14.000 gauss
Volume of enclosure: 41 .9
liters (1.48 cu ft)

Cabinet dimensions: 354 x 635

x 273 mm deep (13% x 25 x
10% in)

Weight: Packed in carton 24.9
kg (55 lb). unpacked 22.6 kg
(49% lb)

The new highrange used in

the AR-11 measures 19 mm

(V. in) across its dome and
preserves very nearly optimum
dispersion up to the highest
audible frequencies.

Guarantee: The workmanship
and performance in normal use
of the AR-11 are guaranteed
for five years from the date of
purchase. This guarantee
covers parts, repair labor. and
freight costs to and from the
factory or nearest authorized
service station. New packaging
if needed is also free. The
guarantee is valid worldwide.

' TELEDYNE
ACOUSTlC RESEARCH

10 AMERICAN DRIVE
NORWOOD
MASSACHUSETTS 02062
TELEPHONE: (617) 769-4200
CABLE ADDRESSIARINT
TELEX : 92-4310

HIGH STREET. HOUGHTON REGIS
DUNSTABLE. BEDFORDSHIRE LU5 fiQJ

ENGLAND
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