Polk SDA II Floorstanding Stereo Dimensional Array Speakers
Polk SDA II Floorstanding Stereo Dimensional Array Speakers - Recently checked out by DALAUDIO and found to be in good working order. The drivers are in excellent condition as are the crossovers. We ran them through our test system and compared them to a pristine pair we have owned since new. Both sets track acoustically similar and both have nearly identical outputs on the RTA (Real Time Analyzer). I have always enjoyed the sound of the SDA II's, which is why I've owned two pair for most of my adult life. One at home and one at the shop. A lot of information both correct and incorrect regarding these speakers is out there, so do your research. I have a copy of the SDA Handbook if you bring a USB drive, it's 106 Pages! We are including the original interconnect cable.
Cash Sale No Holds Call or Text for Pickup
Note 1 - The SDA II speakers require that your amplifier is stable into 4 ohms, and the amplifier must also have a common ground on the output side. While most amps are capable of 4 ohms, please check with me before you decide to buy if you are not familiar with these terms. If you tell me which amplifier or receiver or integrated amp you are utilizing, I can verify you will be ok.
More about the speakers.
First look at the speaker - these are not SDA 2As SDA 2B or 2Cs , These are Polk II and they are getting hard to find. They have two SL 2000 Tweeters (one is part of the SDA imaging), three 6" Mid Range 6501s (one is part of the SDA imaging). They have veneer wood (not vinyl), and they have the interconnect imaging cable (original included). These require a 4 Ohm capable amplifier and then you can throw a lot of power at them. I make the above distinctions as Polk made a lot of very similar looking Model 2's models, with single tweeters, and less midranges with different arrangements and like most audio items, the devil is in the detail.
Stereo Dimensional Array or SDA , The theory is as few word as possible; An interconnection cable connects the left and right speakers. The cable sends a portion of the left channel signal to the right speaker’s SDA array and vice versa. The result has the effect of canceling the crosstalk by making the left ear hear the left speaker only and the right ear the right speaker only. In practice, it is far more effective than one might think. To accomplish this feat the SDA-II speakers are built in left and right labeled mirror-image pairs.
The driver complement works as follows:
- Two 1″ soft dome tweeters horizontally arrayed near the top of the front baffle the inner tweeter is part of the SDA image the outer tweeter is conventional.
- Below the tweeters are a pair of mid-woofers, also horizontally arrayed. The inner mid-woofer is also part of the SDA image and the outer is conventional
- So on each speaker the inner tweeter and mid-woofer are the SDA drivers; the outer pair work conventionally. (Please note the SDA 2's SDA2B SDA 2C arrangements are not like this!)
- Below the two horizontal arrays is another mid-woofer in line with the outer woofer above it
- Below the second line mid-woofer is a 12″ diameter passive radiator.
- On the back the speaker are 5 Way Binding posts, below those is a coded polarized socket for the interconnecting cable connecting the SDA Image between speaker.
Specifications per Polk - SDA II (1984)
- 2 x 1″ Soft Dome tweeter (SL2000)
- 3x 6 1/2″ mid-woofers
- 1x 12″ passive radiator speaker
- Mirror image pair
- Tweeter is fused-protected
- Frequency Response: 16-26,000 Hz. (no tolerance given)
- Sensitivity: 92 dB / w / m Nominal Impedance: 4 ohms Suggested Amplification: 10-500 watts continuous;common ground amplifiers only
- Dimensions: 39 1/2″ H BY 16″ W BY 12″ D
- Price: $1,200.00 (1984 Cost)