ACOUSTIC RESEARCH AR-11 VINTAGE SPEAKERS - REFOAMED W/MATCHING STANDS

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General:
Vintage set of AR-11 speakers with matching stands. A budget friendly alternative to the AR-3's with a similar look and performance.

Both woofers were showing signs of aging so we sent them to our friends at Millersound, the renown world-class speaker restoration shop not far from us in PA.

They now look and work like new and should hold up many decades. The volume and quality of bass produced surprised us during testing in our main listening area, especially considering the size of our shop with its high ceilings.

In super nice "vintage" condition showing some patina and aging, but overall very presentable compared to most.

Tested and working perfectly delivering a nice right vintage sound, just like you remember.

This will ship UPS for an additional $350 anywhere within the lower 48 US states. If you're outside of this area please contact us for a quote as we ship worldwide. Local courier also available.

More from Acoustic Research:
The AR-11 is the most accurate speaker system ever made by Acoustic Research. Its performance, drivers, and crossover are identical to those of the AR-10 except that the AR-11 does not incorporate a Woofer Environmental Control and the associated crossover components.

The AR-11 is designed for optimum performance when placed against a wall, as on a bookshelf, or slightly away from two room surfaces. It uses a substantially improved version of the 305 mm (12 in) woofer with which Acoustic Research introduced the acoustic suspension principle to home listeners, as well as the hemispherical dome midrange of the AR-3a. 

It also uses a newly designed 19 mm (3/4 in) high range 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 techniques that have produced significant improvements in performance over earlier versions. 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 with uniformly dispersed flat energy output to the highest audible frequencies. It is able to transmit the information from a program 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 midrange and high range 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, or live rooms.
The AR-11 shares many of the appearance features of the AR-10, including an easily removable precision-machined foam grill, which was chosen for its near-perfect acoustical transparency.

Crossower network: 
Half-section LC network on each driver using air-core chokes and computer grade electrolytic capacitors, acoustic output of midrange and highrange driver is controlled by switchable resistive networks.

Power requirement: 
Minimum 25 watts per channel for an average room, to obtain a closer approx. of the minimum power required, in continuous RMS watts per channel for the realistic reproduction of musical sound levels in a particular room, divide the volume of the listening room, measured in cube feet by 100; 25 watts (into one speaker only) will produce 100 dB SPL in a 3000 cu ft room of average reflectivity (energy absorption coefficient of 0,15); 50 watts (25 watts per channel) will produce 103 dB SPL in the same room

Power-handling ability: 
Maybe used with amplifiers capable of delivering up to 150 watts continuous power per channel being driven to clipping 10% of the time, on normal music source material

Cosmetic Notes:
- Speaker A - One top front corner of one speaker was repaired at some point in the past.
- Speaker B - Small veneer chip on one rear corner, moderate scratching and yellowish finish blemish on one side.

Brand Background:
Acoustic Research, Inc. (“AR”) was founded in 1954 by audio pioneer, writer, inventor, researcher and audio-electronics teacher Edgar Villchur and his student, Henry Kloss. AR was established to produce the US $185 (equivalent to $1,990 in 2022) model AR-1, a loudspeaker design incorporating the acoustic suspension principle based on U.S. Patent 2,775,309, granted to Edgar Villchur and assigned to Acoustic Research in 1956.

Edgar Villchur's technical innovation was based on objective testing and research, most of which was made publicly available as documents, specifications, and measurements—all of which were then new in the loudspeaker industry.

Ownership:
Single Owner

Amplifier Recommendations:
As little as 10 watts will make these sing

Connections:
Terminals accepting bare wire and vintage spades.

General Sound:
Big beautiful musical sound with little fatigue.

Cosmetic Condition:
6/10 = Fair. Three to four minor scratches, or one major scratch. See our detailed rating description here.

Working Condition:
Working perfectly and tested in our lab and listening room.

Included:
See item description

Packing:
Will be packed using our highly developed in-house process and custom packing materials.Reviews:
Click Here

Specs:
3-way, three driver loudspeaker system

Frequency Response:
27 Hz to 30 kHz

Power Handling:
100W

Recommended Amplifier Power:
25W to 225W

Crossover Frequency:
525 Hz and 5000 Hz

Impedance:
4Ω

Sensitivity:
86dB

Drivers:
Bass:
1 x 12" acoustic suspension

Midrange:
1 x 1.5" hemispherical dome

Tweeter:
1 x 0.75" hemispherical dome

Dimensions - Each Speaker:
13.94" x 25" x 10.75" (354 x 635 x 273mm)

Weight - Each Speaker:
50 lbs. (22.6kg)

Approximate Age:
1978

Link to Manual:
Click Here

Recommended Cables:

Kimber Kable - Speaker Cables - Good

Testing Process:

Our speaker evaluation process starts with a visual inspection of all drivers. We are looking for damaged or deteriorating woofer surrounds, dented tweeter domes, and cone damage. We also inspect the speaker connection points for loose or broken connectors.

After the initial visual inspection we connect the speakers to a reference amplifier with our preferred test tracks. With the speakers placed with proper distance we listen to each driver to make sure that they are producing the intended frequencies with no signs of distortion or rattle. During listening tests with test tracks we check for proper stereo imaging and bass response at various listening levels. If there are any audible signs of issues, the speakers are taken to the bench where we perform a frequency sweep to isolate the issue so that it can be resolved by component repair or replacement.

Our subwoofer evaluation process starts with a visual inspection of all drivers. We are looking for damaged or deteriorating woofer surrounds, cone damage, or rubbing voice coils. We also inspect the input connections for damage.

After the initial visual inspection, we connect the sub at our bench and perform a sine wave sweep from about 200Hz down to around 10Hz. During this sweep we are listening for excessive rattle or other signs of improper function. If the sweep passes, we then increase the input level to evaluate how the woofer performs at high output levels. If the woofer has built in crossover features or multiple connection options these features are tested at this time.

We complete the subwoofer evaluation by feeding the unit with an audio signal in conjunction with our house music system to see how it responds to low frequency content in real world conditions while paired with a full range system.