Goodwill find..........SDA-2/II

Welcome to CP ya lucky ****.:D:p;)


The SDA-2 is a great speaker.

1. The interconnect cable basically expands the soundstage of the loudspeakers. In short, the SDA effect tricks our ears out of being able to locate the loudspeakers; instead of point sources, they're expanded outwards.

2. Fuses blown? The previous owner probably played them too loud or with a poor amp and the fuses were blown to protect the tweeters. Check the back of the loudspeakers for the type of fuse needed; iirc, it's 1AG Fast-Blo. It'll be listed on the back of the loudspeakers, so write down the requirement and make a trip to your local Radio Shack or perhaps a home improvement store.

3. That's probably because of the blown fuses. The original SDA-2's (with three midwoofers; top inside is stereo midwoofer, top outside is dimensional midwoofer, bottom inside is sub-bass woofer) had two fuses a loudspeaker in order to protect the two tweeters. If one or more tweeter is not working, replace the fuse.

4. If they're in decent/good condition, you may be able to get $200-250 if everything's working. You'll probably want to listen to these for a few dozen hours at least to tell if you really want to let them go.




When I bought my SDA-1's, the previous owner had blown at least two of the fuses and actually killed one of the tweeters. I replaced all 4 fuses with the proper type (as I said, I think it's 1AG Fast-Blo) and then the bad tweeter. Odds are that the dimensional (outer) tweeters will still be fine while the stereo (inner) tweeters may or may not be fine. If they ARE dead, replacing the tweeters would be $20-30/ea on eBay.

cov413 wrote: »

will it hurt to run these without the interconnect cable?

It won't hurt them but they are much better with it as that is how they were designed to be played.

If you've got two tweeters in each speaker I'm pretty sure that means you've got the original SDA 2 (not 2A or 2B). I have the same speakers. I haven't played with the fuses, but it sounds like you may not have any bad tweeters. Like chandler9a said, one tweeter and one of the mid-woofers in each speaker is part of the "dimensional array." Those drivers only work if you have the interconnect cable connecting the two speakers. Without the interconnect, you're not going to hear much from them. With no interconnect and the fuse removed for the "normal" stereo drivers (I assume the top slot from your description) you probably won't get sound from either tweeter.

You can make your own interconnect. In a pinch all you need is normal speaker wire. I've been using 16 gauge, just twist and double up the ends to get them to hold firmly in the slots. But, you need to be very careful matching the ends. Polk used a number of styles of connectors. Mine have one longer slot and one shorter slot on each receptacle to receive a long blade and short blade on the cable plug. It is very important that you connect the long to long and short to short. If you cross them you stand a good chance of sending your amp into thermal protection shutdown.

Later connectors have a blade / pin configuration instead, but that may just be SDA 2A's and later. (Earlier ones are different with pins that stick out from the receptacle, but these are very rare from the sound of it.) Same thing applies as far as I know... connect like to like.

Once you have working fuses installed and the interconnect in place you can test it by putting your amp into mono mode or just putting on a simple recording that sends mostly the same stuff to each stereo channel. Turn the balance on your pre-amp all the way to the left. You should still hear the dimensional tweeter and midwoofer working on the right speaker, just fainter. Then you can repeat the test in the other direction. This will tell you if the dimensional drivers are working.

If all is right with the world at this point, you can make a more permanent cable using these to terminate your own cable. http://www.alliedelec.com/search/productdetail.aspx?SKU=7503200 (thx to F1nut I think for providing that link!) I hope the receptacle part on the same site (s-302-ab) can be used in the holes polk drilled in the speakers, cause replacing those it my next project.

Also, I think most SDA's have a warning on the back that says not to use the interconnect with anything other than a common ground amp. That means the amp needs to have both channels connected to each other through a common ground. Using mono blocks or a dual mono amp would be a bad idea.

Good luck, and let us know how it goes. Also, you'll find schematics and other helpful information in sticky threads at the top of the vintage forum too. Now I'm going to go cry myself to sleep thinking about how much more I paid for my 2's.

1AMP FAST-BLO is the type of fuse my SDA-1's take. I'd assume it's the same with your SDA-2's.

http://www.polkaudio.com/forums/attachment.php?attachmentid=42826&d=1251393432
http://www.polkaudio.com/forums/attachment.php?attachmentid=42830&d=1251393515

Connect the two together with an RCA cable, Ken from Polk, now retired told me, works just fine on my stock 2.3....

warren wrote: »

Connect the two together with an RCA cable, Ken from Polk, now retired told me, works just fine on my stock 2.3....

Can't use an RCA on older SDA's they are blade/blade.

cov413 wrote: »

Someone name me a nice vintage reciever that these will match nicely with cosmetically and power wise.

I've run mine with a couple of different integrateds (NAD) and amps (Hafler 9180 and B&K 200.2). Personally, I'd recommend something with at least 100 WPC and a fairly decent damping factor (like better than 300). Moving to a bigger amp really seemed to tighten up the bass for me, and the B&K gave me more warmth and detail in the midbass than the Hafler. The Hafler seemed to be a REALLY neutral amp.

I don't think there's any reason why you couldn't use the Pio at least temporarily... I don't know if I'd try driving your HT speakers and the SDA's at the same time, but I think all the Elites run about 90 WPC or better.

On3s&Z3r0s wrote: »

Sounds like it's worse than that even. From the description, could be this thing (copied the picture from out of the thread for easier reference).

http://www.polkaudio.com/forums/showthread.php?t=24085

Unless you can find some small and well insulated alligator clips like Tide used, I'd say you're stuck pulling those out and replacing them with something else.

You have the same interconnect as I do. Those are definitely early SDA-2's. My S# (on my SDA-1's) is 2075. Anyways, have you sorted out your fuses yet?

Those are early SDA's and I believe Parts Express sells a connector that will work. The search function isn't too good, but I know this issue has come up before and there is a decent fix.

They aren't blade/blade and they aren't pin/blade. Very early SDA's used that funky connector

H9

Very lucky man cov413, Welcome to the family!!