This product is a vintage Polk model and is not available for sale, but it may still be available in some stores as a closeout or used product. The following text is taken from the original sales brochure for this product and does not reflect current availability. If you happen to have any question or concerns about this product, or any other Polk Audio product, feel free to contact our Customer Service Department at 1-800-377-7655 Monday - Friday, 9am - 5:30pm EST


A high efficiency system of awesome and seemingly limitless dynamic range and bass capability which reproduces music with a precise, lifelike, three dimensional soundstage which is unequalled.

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The genius of Matthew Polk redefines state-of-the-art. Introducing the TRUE STEREO SDA signiture reference system.

Matthew Polk's extraordinary new SDA Signature Reference System combines, for the first time, Polk's patented SDA TRUE STEREO technology with phase-coherent vertical line-source multiple driver topology to achieve new levels of state - of - the - art imaging, detail, coherence, dynamic range and bass reproduction.

Polk Audio is pleased to announce the introduction of an extraordinary new loudspeaker, the SDA Signature Reference System. The SDA - SRS will be the flagship model of Polk's highly successful SDA Series which will now be comprised of the SDA-1, SDA-2, SDA-CRS and the new SDA-SRS. This remarkable sounding, 3rd generation SDA speaker combines, for the first time, the latest refinements in Polk's exclusive and patented TRUE STEREO technology with time-compensated, phase coherent multiple driver vertical line-source topology. The result is a high efficiency system of awesome and seemingly limitless dynamic range and bass capability which reproduces music with a precise, lifelike, three dimensional soundstage which is unequalled.

Each 63.75" x 21 x 13 cabinet contains 8 Polk 6.5" trilaminate-polymer drivers, a planar 15" sub-bass radiator, 4 Polk 1" Silver Coil polyamide dome tweeters and an incredibly complex and sophisticated Isophase crossover system. One of the unique features of the crossover is the progressive variation of the high frequency high-pass circuitry which maintains virtual point source operation resulting in wide horizontal and vertical dispersion. Power handling is nominally rated at 1000 watts per channel, although the high efficiency of the system allows superb performance to be realized with even the most moderately powered receiver. Bass performance is, in a word, breathtaking. The use of 8 small active drivers coupled to the large 15" sub-bass radiator results in extraordinarily tight, quick and three dimensional mid and upper bass combined with low and sub-bass capabilities which are staggering (clean output at 25 Hz exceeds 100db!) An elaborate bracing system is employed resulting in a remarkably rigid cabinet which virtually eliminates colorations due to panel resonances. Separate inputs for high and low frequency sections of the system allows bi-wire or bi-amp operation without the need for a separate electronic crossover. The speakers are beautifully finished in oiled oak and walnut.

The world premier of the SDA Signature Reference System will be in Chicago in conjunction with the 1985 CES show at Polk's Congressional Suite at the Americana Congress Hotel.

-excerpt from 1985 Polk Audio promotional information

Driver Complement

Diameter1" (2.54cm) 
TypePolk SL2000 silver coil dome tweeters 
Diameter6 1/2" (16.51cm) 
TypePolk tri-laminate polymer bass-midrange drivers 
Diameter15" (38.10cm) 
Typeplanar fluid-coupled subwoofer 


Total Frequency Response12Hz - 26,000Hz 
Nominal Impedance6 ohms
Efficiency93 dB
Recommended Amplifier Power10 - 750 watts per channel

Amplifier Specs

220V AvailabilityNo 
Amplifier TypeNone 


Cabinet Dimensions
Height50" (127.00cm) 
Width21" (53.34cm) 
Depth13" (33.02cm) 
Product Weight (each)142 pounds


Unit of Measureeach 
Included AccessoriesSDA interconnect cable 


Speaker Warranty5 years parts and labor (original purchaser) 

Specifications, dimensions and features subject to change without notice. For more information call us at 1-800-377-7655 (USA and Canada). Outside of North America call +1 (410) 358-3600.

SDASRS 2 Media

SDASRS 2 Literature

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SDASRS 2 Accessories