Sda-2

High Db.

I just purchased a set of SDA-2's. these dont have a letter designation, so im assuming these are the first generation. they are the ones with 3 midbass, and 2 tweeters side by side. i was under the impression that the stereo dimensional array drivers only worked when the interconnect cable was used between the two speakers. i didnt have the original cable,(these are the blade to blade) but searched the forums, and was able to create my own cable. i thought everything was ok, as all the drivers seamed to be working. but as i listened to them, i just wasnt getting the spacial sound that everyone here says they have. so as an experiment, i disconnected my interconnect cable, and noticed that all the drivers, including the "sda" array was still functioning. i took alook at the crossover schematic thats posted in the forum for the sda-2. and it appears that the "sda" array should only be functioning with the interconnect cable connected. is this correct? should all drivers be working, even though the interconnect is not in play? i have not opened the speakers up yet, since i thought everything was ok. could someone have modified something, to make all the drivers work, with out the interconnect? if so, what might have been done, so i can open up the cabnet and see what would need to be changed to put them back to there original state. i have not owned a set of "sda's" untill now, all though i have several polk models in my collection. ive heard that some people do not like the "sda" effect, and im just currious, if they could have been modified to remove the effect, all though im not sure why, isnt that the whole reason for owning the sda in the first place???

danger boy

even with the interconnect (SDA) cable unplugged.. the dimensional driver still moves. I don't remember if it puts out sound or not... mine appear that it does..... so you don't have a wiring problem.

someone else in here can elaborate.

congrats on your new SDA 2's.

High Db.

they are definitely putting out sound, i can understand that the midbass would still move, because of the air inside the cabnet, however i put my ear up to each driver, and they are without question producing sound, both midbass and tweeter in the array are infact making sound. after looking at the crossover schematic, it appears as if the array gets its positive connection from the input connector, but gets its negative from the other speaker, which is why im confussed as to how all drivers can be working without the interconnect in play, am i ready the schematic wrong?

F1nut

The SDA drivers still produce sound below 100Hz when the cable is disconnected.

It is possible that someone altered the crossovers, you'll have to look inside to determine that.

High Db.

ok, i looked inside, sure enough, someone snipped the wires from the interconnect socket to the array crossover. i see from the schematic that the array crossover sits ontop of the terminal cup. it looks like the original wiring that sent the signal from the terminal cup to both crossovers have been modified to send signal to both crossovers via some creative rewiring technics, thus removing the sda signal, thought i saw in one of the forums that the wiring color scheme was white/green=negative, and black/blue=positive, but does anyone know which wires from the interconnect socket went to were on the crossovers, even though everything works as is, id like to rewire these to put them back to there original state. also, ive seen alot of you have rebuilt/updated your crossovers. has anyone rebuilt the original sda-2 crossovers? and if so, any ideas on cap/coil recommendations..looks like ive got some serious rewiring/checking to do, as now im not sure of the integrity of any of the wires, or polarities, since the previous owner apparently decided to be creative in his re-engineering of these speakers

inspiredsports

High Db - Welcome!

As a first step you might want check out the "Sticky" at the top of the "Vintage Speakers" forum at http://www.polkaudio.com/forums/showthread.php?t=55888 and look carefully at the "SDS 2 Sch.pdf" in Post #3 as I'm 99% sure this is what you are describing. This will help confirm it.

Checking the back of the 6-1/2" drivers to verify they are all MW6501's would also be a good idea to make sure the previous (and apparently adventurous) owner didn't make any strange substitutions as different drivers have different impedance ratings.

There's lot's of room for improvement if you want to make the investment in new tweeters and other areas. The original SL2000's used were a bit harsh to start with, and seem to diminish with age. They can be replaced with "smoother" rubber-clad silk domed RDO194-1's from Polk.

A few tried and true brand specific capacitor/resistor replacement formulas for your crossovers also exist in the group.

You can then move to amp and cabling discussions that will make your head spin and wallet bleed, but man will those SDA's sing !!!

Last, while those vintage 2's are classics, you might want to keep them somewhat "stock" and research group opinion about which models provide the best bang for the buck.

I've dropped a ton of dough into a set of 1986 SDA SRS 2's to get them as far along as they can go (and they are EXCEPTIONAL!!), but I've learned they have a few limitations. Had I waited a bit and learned more from the group, this would have been solved.

I believe you can get a Master's Degree in "Polk" by hanging out here for about 3 months. Look at the number of ratings some of these guys have. It's hard to get a bad answer from guys with 4,000 to 16,000+ posts

High Db.

believe it or not, i was able to pick these up from my local pawn shop for a $100.00 for the pair. either they knew they were modified, or had no idea what they were selling, the cabnets are flawless, and the drivers all apear to be in perfect shape as well. except for the re-wiring issue, they are in mint condition, i tryed to keep the grin on my face from getting out of hand, as i was paying for them..lol, so im hoping i can get these straightened around to bring them back to there original glory

inspiredsports

High Db. wrote: »

believe it or not, i was able to pick these up from my local pawn shop for a $100.00 for the pair. either they knew they were modified, or had no idea what they were selling, the cabnets are flawless, and the drivers all apear to be in perfect shape as well. except for the re-wiring issue, they are in mint condition, i tryed to keep the grin on my face from getting out of hand, as i was paying for them..lol, so im hoping i can get these straightened around to bring them back to there original glory

That is an absolutely "no-brainer" price. "You done good!"

It sounds like you have a true interest in restoring these beauties and you might find this historical site helpful. It seems to be inactive now, but contains a lot of information: http://www.polksda.com/list.shtml

I enjoy visiting the price/year produced page (Vintage Models). It seems like paying approximately 1/4 to up to 1/2 price is average today, so 1/12 was a nice snag!

Marty913

High Db. wrote: »

ok, i looked inside, sure enough, someone snipped the wires from the interconnect socket to the array crossover. i see from the schematic that the array crossover sits ontop of the terminal cup. it looks like the original wiring that sent the signal from the terminal cup to both crossovers have been modified to send signal to both crossovers via some creative rewiring technics, thus removing the sda signal, thought i saw in one of the forums that the wiring color scheme was white/green=negative, and black/blue=positive, but does anyone know which wires from the interconnect socket went to were on the crossovers.

High Db,

When I rebuilt my SDA2's a year ago I posted close-up pictures and a parts list (may not exactly match yours). Do a thread search on marty913 with a keyword of SDA Upgrade and you should find it (January of last year). It may give you some perspective anyway.

inspiredsports

Marty913 wrote: »

High Db,

When I rebuilt my SDA2's a year ago I posted close-up pictures and a parts list (may not exactly match yours). Do a thread search on marty913 with a keyword of SDA Upgrade and you should find it (January of last year). It may give you some perspective anyway.

This is all that comes up searching "marty913 SDA2" http://www.polkaudio.com/forums/showthread.php?t=60573

High Db.

wow!!..i just printed out your thread, this is exactly what i needed the pictures are perfect!! with this info, i should be able to re-wire things..thank you very much!!

Marty913

High Db. wrote: »

wow!!..i just printed out your thread, this is exactly what i needed the pictures are perfect!! with this info, i should be able to re-wire things..thank you very much!!

If you need more, I can pull my notes or the passive and take more pictures. Just let me know if you need anything.

Marty913

inspiredsports wrote: »

This is all that comes up searching "marty913 SDA2" http://www.polkaudio.com/forums/showthread.php?t=60573

This should be the thread if I'm doing this right?? Sorry, I just figured it out (slow learner).

http://www.polkaudio.com/forums/search.php?searchid=4054928

High Db.

just one more thing marty, i also plan as part of the rewire, to add a secondary set of posts for the sda connection. when the owner snipped the wires to the sda socket, he snipped them clear down, so i cant tell which color wire went to which pin on the socket. ie: does the white wire=small blade, blue= large blade? and it looks like the socket is reversed from one speaker to the other, so that large on top, small on bottom, of one speaker, and small on top, large on the bottom of the other speaker, i wanna make sure i make this connection properly so i dont create maximum smoke with my receiver(vintage kenwood kr-9600) i couldnt tell from your pics do you remember the color combination for the sda socket..thanks again

Marty913

High Db. wrote: »

just one more thing marty, i also plan as part of the rewire, to add a secondary set of posts for the sda connection. when the owner snipped the wires to the sda socket, he snipped them clear down, so i cant tell which color wire went to which pin on the socket. ie: does the white wire=small blade, blue= large blade? and it looks like the socket is reversed from one speaker to the other, so that large on top, small on bottom, of one speaker, and small on top, large on the bottom of the other speaker, i wanna make sure i make this connection properly so i dont create maximum smoke with my receiver(vintage kenwood kr-9600) i couldnt tell from your pics do you remember the color combination for the sda socket..thanks again

Rather than tie up the thread, can you give me an email address (or send me an email - my email is in my profile), and secondly, can your read an MS Excel & Word file. I can send you my diagram notes. If not, we can do it here - just don't want to bore everyone. My notes have a layout, color codes, etc.

High Db.

my email address is [email]highdb@hotmail.com..thanks[/email] again for your help

High Db.

yes i can read both word and excel

Marty913

High Db. wrote: »

yes i can read both word and excel

File sent via email.

PW47

f1nut wrote: »

the sda drivers still produce sound below 100hz when the cable is disconnected.

It is possible that someone altered the crossovers, you'll have to look inside to determine that.

hy how can ifind the interconnetion cable for sda 2 model r have one round pin and bellow an horizontal entrance ? Worth to buy withouth the cable?

F1nut

The pin/blade cable is no longer available. You'll have to make something yourself.