Polk SDA 2B Floorstanding Stereo Dimensional Array Speakers 1988-89
Polk SDA 2B Floorstanding Stereo Dimensional Array Speakers - These were recently checked out by DALAUDIO and found to be in good working order. All drivers are in excellent condition as are the crossovers. We ran them through our testing, and testing per the SDA manuals (see below). Both track acoustically similar and both have nearly identical outputs on the RTA (Real Time Analyzer). I think these sound fantastic as do many others. If you check reviews make sure its the 2B model. A lot of information both correct and incorrect regarding SDA 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!
Physical condition -7-8 as it has a few corner issues that are hard to see due to the grill. I took a photos of it. Otherwise the condition is good. Please see all photos. The unit is picture missing two of the grill guides, I will have new ones installed by the time you review this ad.
Cash Sale No Holds Call or Text for Pickup
Note 1 - The SDA 2B speakers require that your amplifier is stable into 6 ohms, and no bridged amplifiers, and the amplifier must also have a common output ground between channels. Most amps are capable of 6 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.
Note 2 - Condition, please see all photos one of the corners has been repaired. It looks great at a distance of about 2 ft, but closer you an see the repair (please see photos). Grills needed new holding tabs on the speaker - there were replaced by DALAUDIO. Please see all photos.
More about the speakers.
First look at the speaker - these are not SDA 2s nor are they the SDA 2C , These are Polk 2B and while available its harder to find fully working units with the interconnecting cable. This pair has one SL 2000 Tweeters, two 6" Mid Range 6501s (one is part of the SDA imaging). They have vinyl covering, and they have a proper polarity keyed connectors and cable made by DALAUDIO for the interconnect imaging. The cable is worth $65-80 alone! These require a 6 Ohm capable amplifier and then you can throw quite a bit of power at them. I make the above distinctions as Polk made a lot of very similar looking Model 2's and the devil is in the detail.
SDA- or Stereo Dimensional Array is a speaker that is equipped with an interconnection cable connects the left and right speakers. The cable feeds the left channel signal to the right speaker’s SDA array and vice versa. This has the effect of canceling the crosstalk, 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 speakers are built in left and right labeled mirror-image pairs.
The driver complement works as follows:
One 1″ soft dome tweeter near the top of the front baffle, acts as a progressive point source. Below the tweeters are a pair of mid-woofers, horizontally arrayed. The inner mid-woofer is also part of the SDA image and the outer is conventional. So on each speaker the tweeter and mid-woofer are the SDA drivers; the outer mid driver work conventionally. (Please note the SDA 2's SDA2C arrangements are not like this!)
Below the two horizontal arrays 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 (1989)
3-way configuration, closed box (passive radiator), bass radiator Polk Audio SW121 300mm, rubber surround,
1 x polymer cone mid woofer Polk Audio MW-6503 165mm SDA dimensional driver rubber surround
1 x polymer cone midwoofer Polk Audio MW 6511 165mm, stereo driver, rubber surround
1 x 25mm coil dome tweeter Polk Audio SL 2000 25mm Progressive point source
Power handling is 30-350W@6Ω
16-20000Hz ±3 dB, 38-20000Hz -3 dB,
Sensitivity 90 dB, 1W/1M