The performance standard for the AR-12 is the same as for our AR-11 speaker system; reproduction of the music program source with the maximum degree of accuracy. While the AR-11 is as accurate a loudspeaker as our engineering skill enables us to make, with the AR-12 cost is an additional consideration. The main differences between the AR-11 and the AR-12 are that the bass response of the AR-11 extends approximately 1/2 octave lower, and the AR-12 is lower in cost.
The AR-12 employs a 10-inch acoustic suspension woofer installed in a cabinet of the dimensions normally used for our 12-inch units. The result is superior bass performance, with extended range and very low distortion, that is more than adequate for all music except perhaps the most demanding organ or electronic music recordings.
A new midrange driver has been developed especially for the AR-12 with a rear cavity specifically tailored to provide the correct stiffness, restoring force, and controlled damping required for optimum response at lower midrange frequencies. It combines a 1-inch voice coil, for high power-handling ability, with a relatively small 2-1/4-inch cone for excellent dispersion over the driver's entire operating range. A greater volume of sound is therefore available with no sacrifice in musical accuracy.
The combining of a relatively large voice coil with a small cone does not require, not is ot desirable to use, a conventional "spider" for centering the voice coil. An entirely new method of centering has been devised for the AR-12 midrange, using magnetic fluid to "float" the voice coil in the gap between magnet and pole-piece.
The use of magnetic fluid suspension, in turn, provides two additional benefits. Improved linearity of motion results in lower distortion than a design using a conventional spider. And the magnetic fluid also acts as an efficient path for conducting heat from the voice coil to the speaker's magnet assembly and metal frame, where the heat is readily absorbed. This yields an additional increase in power-handling ability. The diagram on the ither side of this sheet gives more information on this point.
The magnetic fluid suspension has also been incorporated into the 3/4 inch hemnispherical dome highrange driver of the Ar-12 for increased power-handling ability.
The cabinet molding of the AR-12 has purposely been kept small in order to eliminate audible interference effects that are normally caused by sound waves being reflected from cabinet projections. This design feature has been incorporated into all rcent AR speaker systems, including the AR-11, AR-10Ï€, AR-14, and AR-16.
The AR-12 has been designed to achieve an appropriate balance between flat energy response and flat anechoic response. It is capable of an extremely high degree of accuracy in reproducing music under most listening conditions. In addition, a pair of three-position switches provides a means of tailoring the level of midrange and highrange drivers to individual rooms. The "0" position of the switches should provide the most accurate results in most listening rooms, while the -3 dB and -6 dB settings are useful for compensating for the efects of more reverberant, or "live" rooms.
Specifications
Type: 3-Way system
Power Handlig: 100 Watt
Impedance: 8 Ω
Frequency Response: 36 - 30,000 Hz.
Low Frequency Driver: 10-inch woofer
Mid Ragne Driver : 2-1/4-inch cone
High Frequency Driver: 3/4-inch dome
Crossover: 700 Hz and 4000Hz
Volumen: 41,9 Liter.
Dimensions : 354 x 635 x 273 mm (13,9" x 25" x 10,7")
Weight: 17 kg (37 lb 7,1 oz)