Parts list for SDA 2 crossovers

mgebel70

I know this has been asked on here before; but every time I find a post with a link that may help; the link ends up not working. Anyways. I am new here and new to SDA speakers. I recently picked up a pair of SDA 2 speakers with one passive radiator, three woofers, two tweeters and two glass fuses on the back of the speaker. They work perfect and sound great, but I'd still like to rebuild the crossovers. I'm not an electronics tech, but I'm comfortable and competent with soldering. I have looked inside and everything appears to be original. I don't have or make a ton of money, so I'd just like to start with basics. What should I replace immediately and what can wait? Also. On the top crossover is a resistor with two capacitors piggy backed on to it, and on both crossovers are capacitors with another capacitor piggy packed on to them as well. Do I need to stick with those configurations, or can they be eliminated due to current technology? What I really need is a parts list of current parts that replace the old. And on that list what parts should be replaced immediately and the ones that can wait. Or I can just wait until I have enough money to do everything. Because from what I've been reading, it sounds like the parts are going to be a few hundred dollars. Also. There is a guy on ebay that specializes in rebuilding vintage Polk crossovers. But it looks like it would be two hundred dollars just in labor for SDA 2's. Worth it or not? Please guys: Any help or insight would be greatly appreciated.





. Worth it or not? Please guys: Any help or insight would be greatly appreciated.

F1nut

Caps per speaker:

(1) .5uF
(2) 12uF
(2) 27uF

Resistors per speaker:

(2) 4 ohm 10 or 12 watt
(2) 2.7 ohm 10 or 12 watt

Eliminate the 750pF bypass caps.
Upgrade everything together.

ZLTFUL

Mills is sort of the go to for resistors. Sonicaps for capacitors. Both can be had from Sonic Craft.
http://www.soniccraft.com/index.php/sonicap-gen-c-301_49_50
http://www.soniccraft.com/index.php/mills-12-watt-c-29_53_63

Personal recommendation would be to go that route versus lower cost/quality parts. Sure, you can get Dayton caps for less but then what is the point.

teekay0007

Also worth mentioning, for best results with your model of SDA-2s, most here seem to prefer the sound delivered after disconnecting the SDA tweeter (the outer one) as part of their mods/upgrades process.

F1nut

An excellent point teekay0007 and highly recommended. If the OP chooses to do that remove (1) 12uF cap, (1) 4 ohm and (1) 2.7 ohm resistor from the list.

mgebel70

Hi F1nut:

Thank you for responding. I've literally spent days pouring through these forums and I've seen your replies more than once. You must devote a lot of your time to these forums, and I thank you for that. I do have a couple more questions. So please bear with me. I've read a lot of others recommendations for Sonicaps. But is there a certain type or brand of resistor I should be using. Or can I just go down to Radio Shack for resistors.

mgebel70

Thank you ZLTFUL:

Sonicaps and Mills it is then. As stated; I have a limited budget to work with. But I definitely don't want to cheap out on this project. A big thank you again to ZLTFUL and F1nut.

mgebel70

Thanks again guys:

Good idea Teekay0007. Since my speakers do work. I can actually try that now and see if I like it or not. And since I mentioned the speakers working, I'll tell you guys a funny story.

I actually picked up the speakers off of Craigslist for $197.00 dollars. Yea I know. $197.00..? I didn't even ask. I just gave him his money and came home. I didn't even here the speakers. He had them in a conference room with nothing there to test them on. Anyway. I brought them home, wired them up to my Stereo, plugged in the IC cable and listened away. It's funny. You don't realize how terrible bad speakers sound, until you hear some good ones. I had some old Yamaha NS A180's before these, and I was quite happy. Now my Yamaha's have been relegated to garage duty. Well after listening to the SDA's for a while and putting my ear up to every speaker; I realized that the two dimensional speakers on the right channel weren't working. I checked the fuses, I checked for a good connection with the IC cable. They both checked out good. I removed the IC cable and checked continuity. That checked out OK. I then removed the speakers and swapped them around to the ones that were working. I then find that one tweeter isn't working. Turns out the tweeter had a broken lead wire. I fixed that and retested. Still no sound from the dimensional side. I checked resistance at the speakers. That was OK. I pulled off the radiator and checked for bad connections. Found none. I then removed the crossovers and started removing capacitors and checking them. they were OK. I checked the resisters. They were OK. I re soldered and re assembled everything. Took a listen, and still nothing. I then decided it must be a problem with the left speaker sending a signal to the right. So I did all the same procedures to the left speaker as I did to the right. Still nothing. Well: What I didn't do was check the IC cable while the stereo was on. Because when I pushed my left speaker back into place; I heard the dimensionals kick in for a second on the other side. I then grabbed the IC cable and they came on again. I let go of the cable and they went off. The cable was fine. Just dirty connections in the speaker. So after all that work; it was just a bad connection. I don't know why I didn't check those connections with the stereo on. And I don't know why I didn't just clean those connections to begin with. I was going to; but after looking at them decided they were OK. Lesson re learned. Start with the simple things and don't rush. Be thorough.