Sda - crs

rodman_sda

I have a very old pair purchased by my father in the 80's (2 tweeters). What do you think of these? To me they sound OK but when doing a recent side by side with ADS L520's they struggled to hold their own. More bass, but the mids were an equal match and then the highs... They weren't as "sharp" and I kept going back to the ADS as the better speaker. I gave them a dose of high power and no problems. The SDA cord has long since disappeared so I bridged them together so they work as a single speaker. If you do this watch out the DC resistance dropped to ~ 3.2 ohms. The fact that both were the same reading on a high end Fluke meter means that they got lucky at the factory or the quality of components are tops (probably the real reason). I know that some improvements can be made, tweeters, crossover parts (these look to be very good quality). Any feedback would be appreciated.

BTW - I did make my own SDA cord (simple spade connects, one filed down)
but these sit stacked in a corner where the true nature of SDA would
not be heard.

F1nut

The SDA cord has long since disappeared so I bridged them together so they work as a single speaker.

You did what?

How you expect to judge the sound of a PAIR of speakers like that leaves me shaking my head.

FTGV

rodman_sda wrote: »

Any feedback would be appreciated.......
but these sit stacked in a corner where the true nature of SDA would
not be heard.

First thing before atempting any mods would be to set them up correctly.

inspiredsports

rodman_sda wrote: »

I have a very old pair purchased by my father in the 80's (2 tweeters). What do you think of these? To me they sound OK but when doing a recent side by side with ADS L520's they struggled to hold their own. More bass, but the mids were an equal match and then the highs... They weren't as "sharp" and I kept going back to the ADS as the better speaker. I gave them a dose of high power and no problems. The SDA cord has long since disappeared so I bridged them together so they work as a single speaker. If you do this watch out the DC resistance dropped to ~ 3.2 ohms. The fact that both were the same reading on a high end Fluke meter means that they got lucky at the factory or the quality of components are tops (probably the real reason). I know that some improvements can be made, tweeters, crossover parts (these look to be very good quality). Any feedback would be appreciated.

BTW - I did make my own SDA cord (simple spade connects, one filed down)
but these sit stacked in a corner where the true nature of SDA would
not be heard.

Can you elaborate on what you mean when you say you ". . . bridged them together so they work as a single speaker?"

It seems like you might have properly fashioned an interconnect, but that in no way makes them operate as a single "bridged" speaker. The fact that you have them stacked on top of one another in a corner is another matter.

Can you set the left about 3' from the left wall, the right about 3' from the right wall, both about 6" from the back wall, leave about 6 to 8 feet between the two and then power them with a decent source?

I'm also curious why you think the fact that the two speakers yield the same reading on your VOM is in any way remarkable. I have $8 per pair plastic computer speakers that do the same.

Joe08867

Just one comment: Sell them to someone that will use them as intended.

You are comparing two different animals and doing it poorly. The SDA's need to be set up a specific way to work and they need the interconnect to do there thing. Without the cable you loose the sound from one driver in each cab.

civilian

I checked the date, nope not April 1st yet?
Got any pics of the setup?

rodman_sda

I knew that there would be some here distrubed by my crossover mod but as I said the listening area does not permit more than shoving these way back into a corner stacked. I know this is far from optimum but it's what I have to work with. Making all drivers work without the tether is easy and can also be done by hooking one of the spade outs to ground (lower one??). Anyway I found a schematic of the crossover and did it by adding a jumper wire to two existing locations within the crossover. Funny thing is, both places already have a plated hole, like there was some other intent here that was never utilized?? It would be a five minute fix to unsolder and remove this jumper to restore as original and even faster to remove the driver and simply cut it. As for the VOM reading, remarkable, yes, this was set to read a resitance value down to 0.XX and it was dead on. Overall I'm pleased with the sound but the ADS have a littler more and maybe the intended wiring would spereate the the two definitively but I don't think so. I have read here how adding a later/better model tweet does improve the upside.

Tony M

I've owned alot of ADS speakers and I feel the one model# L710 does have exceptional clarity over anything on the market, other ADS's really sound about the same as these SDA-CRS's. But here's the problem with what you have done.

I think you have taken the SDA-CRS's "specially designed cross-overs" and rewired them as to have nullified their special attributes to creating a spacious and live sounding soundfield.

Your speakers surely would have benifited from the newer tweeters. I have replaced some in a set of SDA-SRS2's and have heard a great improvement.

I'm really sorry you were hasety in tring to make them sound better. I've made many regretable mistakes that I cannot reverse. BUT, you can reverse your rewiring design back to the original way and get that interconnecting cable hooked up right.

They still won't be as clear as an ADS L-710, but the soundfield and power handleing will make you smile big and wide. It does that to most who hear mine. They can't believe all that sound comes from my SDA-CRS's. I own two pair of them , but have yet had the funds to replace their older tweeters. In time I will on one of my sets for sure...

F1nut

Funny thing is, both places already have a plated hole, like there was some other intent here that was never utilized??

That plug is where the blade/blade terminal use to be before they came out with the pin/blade models and moved the terminal to the binding post cup. Still having plenty of blade/blade style cabinets on hand, Polk put a plug in the hole.

As for the rest, it's obvious that you don't have a clue. Please sell them to someone that does.

inspiredsports

F1nut wrote: »

. . . as for the rest, it's obvious that you don't have a clue. Please sell them to someone that does.

After you get to 100 posts :biggrin:

rodman_sda

What I REALLY like about this forum is the feedback from other members, good or bad. It shows the conviction of many for the SDA line, thank you to all.

Regarding the tweeter upgrade, where can I get these? I would also like to buy another tether, are these still around? It is easy enough to make one but an OEM model will be more secure and avoid shorting the amp as my homegrown cord could. After a reassessment of the listening area, a proper positioning can be achieved but only by hanging these from the ceiling. I'd prefer to not put holes in the cabinet. Anyone ever do this with this model?

vc69

Placement with ANY speaker is critical, but even more so with SDA's. You are off to a rough start without the proper cabling. There is a guy on here that can make you a cable and the RDO tweeters are available from Polk customer service. I would concentrate my efforts on getting said cable and re-arranging my listening room to suit proper placement. You cannot even begin to assess the sound quality of your setup until those two things happen.

Tony M

vc69 wrote: »

Placement with ANY speaker is critical, but even more so with SDA's. You are off to a rough start without the proper cabling. There is a guy on here that can make you a cable and the RDO tweeters are available from Polk customer service. I would concentrate my efforts on getting said cable and re-arranging my listening room to suit proper placement. You cannot even begin to assess the sound quality of your setup until those two things happen.

So true.

When your in the sweet spot of a properly spaced set, Holographic soundstage with the artist's voice coming right from where the mic/mics was/were set up is something to hear/behold at least once in a lifetime.

I have not heard about a hanging set but why not. I would like to see them on a hanging shelf instead of eye screws placed into those cabinets. You have a somewhat of a pair of gems there. Respect them and they will repay you with sound that costs alot of money in their day and since you can't buy anything on the market today that does what they do, that makes them priceless in todays market. But you can get these used for a fraction of what they cost back then and that's the beauty of this. You get Diamonds for cubic zurconia prices. Gotta love it!!

I'm glad you mentioned giving these more respect than you first did. I was so glad to read that. Some people don't listen well but you certainly do. You can have Ben make you a cable and then listen again to them if you can before you buy those tweeters. Some tweeters still sound ok if your lucky enough. But you will get an idea of their spacial properties. Most like it, some don't. You'll still have to be the judge with your own ears as to whether they are worth another 200.00 to you or not to smooth out the highs and add even more "air" to them.

Good luck to you,
Tony