What have I got here? (SDA II)

polkerface22

I'm an incurable collector -- of stereo eqpt. among many things. Recently, I found a pair of not-particularly-well-treated speakers in a thrift store. Got them for very little.
They're Polk Audio, and are marked SDA II on the back; their serial numbers are (I believe; I don't have them here at present) the 1,000's range. They are large and very heavy.
Though the exteriors look rough, the interiors may not be all that bad. One of three mid-range (?) speakers in one cabinet is completely drawn back in, with no movement when lightly pushed. Its rubber "foam" is pretty shredded. Also, the rubber cap on one of the tweeters is missing. And, though I can't currently see it to describe it, I believe that one cabinet's plug-in port for the (to me very unusual) cable that runs exclusively between the two cabinets may have the pins bent or otherwise damaged.
I haven't hooked them up, so don't know anything more about them. Happily, I came across and joined this forum.
I wonder what I've got. Some scouting on the web suggests that these were, at one time, pretty premier speakers... even, possibly, that they still are. I'm not concerned with the exteriors -- could deal with them in a number of ways -- but am very concerned about/interested in the sound.
So...
1. Though I understand that any answer would be a shot in the dark with this little information, would they be worth repairing?
2. I think I read somewhere else on this forum that there are no replacements for the rubber "foams." So, I'd need to replace the entire midrange speaker?
3. I think I read, again in this forum, that the speaker problem I described might be a familiar one. Where might there be more info?
4. If the cross-cabinet cable port is maimed, is it replaceable or refashionable? If not, how much do I lose if I simply hook them up like normal speakers, w/o the cross-cabinet cable: a. As regular stereo speakers; or, b. as part of a larger ensemble?
I'm sort of excited, but way out of my depth here; so, any assistance of any kind would be genuinely appreciated. Thanks!

helipilotdoug

Welcome to Club Polk. When you can do it, post some photos of your SDA's to help identify them. Also remove a driver from each side of the cabinet so you know which mid woofers you have. The model number of the driver will be on the back.

1. Though I understand that any answer would be a shot in the dark with this little information, would they be worth repairing?

Depending on the extent of damage, to the cabinets, they probably are. However be ready to spend a few bucks to replace some drivers, and rebuild the crossovers.

2. I think I read somewhere else on this forum that there are no replacements for the rubber "foams." So, I'd need to replace the entire midrange speaker?

Yes. Look in the for sale area, or post in the wanted area here at Club Polk. Most any driver can be found here among the Polkies. If not, Call Polk Customer Service. They have new replacement drivers. Let them know you are a club polk member for a discount. How are the passive radiators?

3. I think I read, again in this forum, that the speaker problem I described might be a familiar one. Where might there be more info?

If you mean the driver that's not moving, search around here at Club Polk. I know I've seen some info on that. A replacement driver is going to be your best bet IMHO.

4. If the cross-cabinet cable port is maimed, is it replaceable or refashionable? If not, how much do I lose if I simply hook them up like normal speakers, w/o the cross-cabinet cable: a. As regular stereo speakers; or, b. as part of a larger ensemble?

The interconnect between the speakers can be redone and/or replaced. Search here on the forum and you should find some info on what others have done. If you do not use the interconnect, you lose the whole reason for having a set of SDA's. They should put out sound, but not what the speakers were designed to do.

I'm sort of excited, but way out of my depth here; so, any assistance of any kind would be genuinely appreciated. Thanks!

Best of luck with your SDA's. Sounds like you have some work to do, but the journey can be rewarding. :biggrin:

Joe08867

I will tell you now you have Original SDA2's. I have a set as well. They have to tweeters horizontally and Three drivers two on one side and one on the other. And they have one 12" Passive Radiator per cabinet. If you description is correct they look like these:

On3s&Z3r0s

Those definitely sound like original 2's. If the tweeters look like the ones in the pictures above then they are some of the very first 2's ever produced with the SL-1000 tweeters. If you have the more common 2's they will have the SL-2000 tweeter with the words Silver Coil printed on them. If you have a frozen driver and especially with a shredded surround you'll need a new one. If you pull it out, it should be an MW 6501, and you can find them used or Polk customer service might have modern replacments in stock. You'll probably want to find a replacement tweeter too, and the SL-2000 can also be found used very easily. Replacing the tweeter with a new version could mess up the sound because of the mismatch, so replacing with a used one is probably your best bet there.

You might also take a look at this post and decide whether you might like to disable the dimensional tweeters anyway: http://www.polkaudio.com/forums/showthread.php?t=114244

If the sockets for the interconnect cable are broken they can be replaced with these:
http://www.alliedelec.com/search/productdetail.aspx?SKU=7503001. Like the other posters have said, the SDA is pretty much the point of the speaker so that's a worthwhile fix for sure.

Congrats on your score, and best of luck!

polkerface22

Thanks for the quick and helpful information!

They're definitely SDA II's.... and I WISH they looked like the ones in the photos: They've got scrapes, scratches, at least one water ring on top, etc. But, again, it's the sound that I'm most interested in at present.

Again, they're currently in storage, so I don't have photos or detailed information on them right now. The only problems I saw during my quick initial look were the ones I listed. Didn't know any particular manual-type tests, so just gave the drivers (I'm going to have to look up "passive radiator") a slight and gentle nudge to see if anything was frozen or rubbing; except for one mid, there wasn't.

I'm a teacher, and so will probably have to put off any serious tinkering until summer (...though I'm feeling pretty eager to get into them immediately...). Meanwhile, I'll start looking -- here, and in the online sales/auctions -- for a couple of parts. Glad to hear that I can do my own interconnect cable, if necessary, and that there are still compatible parts for these guys around.

Anyway, I've been peeking around your forums, and it's clear to me that I'll be doing a lot of Club Polk browsing and reading from now on.

Again, thanks!