Original SDA's - recommended parts list

djf

Anybody know where to find the recommended crossover parts list for the original SDA-SRS's?

I've done the tweeters and everything else in in just about mint condition, but they seem to have lost some of the SDA effect, near 30 year old caps can do that sort of thing to you...

Thanks!

kcoc321

Here is a link to the wiring/ crossover diagrams.
http://www.polkaudio.com/forums/showthread.php?55888-POLK-AUDIO-Speaker-Wiring-Schematics-amp-More-Stereo-Dimensional-Array(SDA)

xsmi

Here you go. Good luck!

http://www.polkaudio.com/forums/showthread.php?72401-POLK-AUDIO-Speaker-Parts-List

Nightfall

This may also be beneficial.

http://vr3mods.com/uploads/SDA_Handbook_2011_Rev2.pdf

westmassguy

djf wrote: »

Anybody know where to find the recommended crossover parts list for the original SDA-SRS's?

I've done the tweeters and everything else in in just about mint condition, but they seem to have lost some of the SDA effect, near 30 year old caps can do that sort of thing to you...

Thanks!

The Original SRSs are quite expensive to upgrade. I've done several of them. The 92uf and the two 130uf caps per crossover are expensive if you go all Metalized Polypropylene. You can use fresh NP Electrolytics. They'll fit on the board and do the job, however the they won't do the SRSs any justice as far as sound quality. If you do go with all Metalized Polypropylene, you'll need to make a riser board, or remote supplemental board to mount the large caps. A good compromise for all Metalized Polypropylene, is all Sonicap or Clarity ESA for the Hi-Pass, and Dayton 5% for the Lo-Pass. Dayton makes a 90uf, which is within 2% of the original value for the 92uf NP Electrolytic, and three 90ufs wired in parallel for the 260uf (130 X 2) is within 4% of the required value.
If you go with Clarity ESAs, Clarity PXs can be used for the Lo-Pass, but they will be more expensive than the Daytons, and they are huge caps. Solen is also an option for the Lo-Pass circuit, but again they will be more expensive than the Daytons
Sonicraft has Mills MRA-12 Resistors in all the values you'll need. If you're replacing the Polyswitch with a 0.5 ohm resistor, I'd recommend two 1.0 ohm resistors in parallel. This will give you an equivalent 0.5 ohm 24 watt resistor to handle the four tweeters.
As always its up to you how much you're willing to spend on upgrades.

Schurkey

westmassguy wrote: »

The 92uf and the two 130uf caps per crossover are expensive if you go all Metalized Polypropylene.

91uF, and 130uF. Reasonable prices, 3% tolerance. Recommended.
http://www.erseaudio.com/Products/PulseXAll/MPX25-03-91-00

http://www.erseaudio.com/Products/PulseXAll/MPX25-03-130-00

westmassguy

Schurkey wrote: »

91uF, and 130uF. Reasonable prices, 3% tolerance. Recommended.
http://www.erseaudio.com/Products/PulseXAll/MPX25-03-91-00

http://www.erseaudio.com/Products/PulseXAll/MPX25-03-130-00

Same price as the Daytons, actually $2.00 more. Still have to add in the rest of the caps and the boatload of resistors.

dcoil

All of the above is really good info! I'll just chime in to say that you WILL NOT BE DISAPPOINTED by investing the time and money in this upgrade. And while your at it, take a look at upgrading the inductor - really a nice bump in the bass department. You can find several threads on the inductor upgrade. No upgrade did as much for my SRS as the xovr. Let us know your thoughts (sounds??) after the upgrade.

djf

Thanks to all for the replies, I am getting a good idea of what I need. One more question.

Many here would say I am sure if I do the job to do the caps AND the resistors at the same time.
Being able, maybe even adept at electronic work and replacing discrete components, I am sort of inclined to do the caps and do the resistors at a later time.

Ideas? Thoughts? Criticisms?

My setup is the original SDA-SRS's, being driven by two Behringer A500 amps, with a BSR 3000 equalizer and a Magnavox VCR/DVD recorder.

I recently got the Magnavox, which can do live streaming recording to DVD, and I would very much recommend it to anyone interested in recording vids.

Thanks!

westmassguy

djf wrote: »

Thanks to all for the replies, I am getting a good idea of what I need. One more question.

Many here would say I am sure if I do the job to do the caps AND the resistors at the same time.
Being able, maybe even adept at electronic work and replacing discrete components, I am sort of inclined to do the caps and do the resistors at a later time.

Ideas? Thoughts? Criticisms?

My setup is the original SDA-SRS's, being driven by two Behringer A500 amps, with a BSR 3000 equalizer and a Magnavox VCR/DVD recorder.

I recently got the Magnavox, which can do live streaming recording to DVD, and I would very much recommend it to anyone interested in recording vids.

Thanks!

Have you actually pulled the crossover yet, taken a good look? You might want to rethink that. The SRS crossover is 3rd generation, huge, and the leads for the tweeters and woofers are soldered to the board. It's not something you can just unplug. My advice, enjoy them as they are, gather all the Caps and Resistors, however long it takes, then do all the crossover work at the same time.

westmassguy

Here's one I did a few months back to give you an idea of what's involved: http://www.polkaudio.com/forums/showthread.php?148952-SRS-Rebuild

westmassguy

dcoil wrote: »

And while your at it, take a look at upgrading the inductor - really a nice bump in the bass department. You can find several threads on the inductor upgrade. No upgrade did as much for my SRS as the xovr. Let us know your thoughts (sounds??) after the upgrade.

Excellent point. The Dimensional Inductor upgrade isn't mentioned as often as the Cap and Resistor upgrade. You can have custom large gauge air core inductors made, which are very expensive, or use a quality Laminated Steel Inductor. I use Erse SuperQ laminated steel inductors. They are arguably the best in class for this type of inductor. I replaced the original 5.8mh inductors on my 2As, and the difference in the low bass was dramatic. Even more so when I did my CRS+s.

djf

In answer to your question, yes, I have pulled the xovers, years back when I replaced the polyswitches.

Very good idea to accumulate the parts before I do anything. I am aware of the soldered connections to the boards and might well add in some in-line plug in connectors.

Also, I need to pop at least one out to take a ton of digital pics before I do anything.

Thanks!