Identity Crisis SDA SRS 1.2 or TL?

thehaens@cox.net

The short story:

My buddy and I pick up some 1.2's up in Northern CA. Come back, take a listen, I recommend replacing the SL-2000's to the Silks. I order them, they come in (2 Days Later), we replace them. So far so good.

I have some 1.2's and the wiring was reveresed on the diagram on the rear of the speaker. In other words, my neg. speaker post was wired to the pos. input on the crossover, and vice versa w/ the pos post.

So I pull of his crossover to check his wiring, and I was shocked to see a very small crossover. I tell him, this is really weird, my crossover is easily twice the size of this one, maybe even 3 times. Here is the pic of it:

I browse the forum, and it looks like he has a TL' crossover(s) both R and L are the same. The kicker is the date on the crossovers. Feb 27, 1988, which is exactly the date stamped on the back of the Sl2000 tweeters that we pullled out.

So, what gives here? The ser# on the back says 1.2 XXXX, looks to be a TL crossover, w/ 1.2 tweets. It is a Pin/Blade IC. I am unsure of the cabinet of the TL' but am going up to another friends house on Sunday to pull his TL's apart to replace his 3000's w/ the silks..

""""Confused""""""

Scott

fredv

Hi Scott,

How about cross reference the parts and the 1.2 and the TL's schematics?

F1nut

Are you sure that yours are not SRS's instead of 1.2's. The SRS crossover is quite large.

thehaens@cox.net

Fred - I did just that, and that is where I am "confused" it is a TL crossover, no doubt, my confusion comes in on the date on the crossover, being that I was under the impression that the TL didn't come out till 89 (?) and since it is a TL crossover, what was it doing matched up w/ SL2K's and not the 3K's? We thought it could of been that a previous owner (not the last, he only owned them for 8 years and never replaced anything) replaced the tweets accidentally to the 2000's.

But the strange thing was the dates match on the crossover and the tweets, making me believe these babies were in stock form.

I'll get more photos, but my camera is now sitting in Florida getting repaired. I guess the camera was confused about the whole thing as well.

F1 - Nope, mine are pretty obviously 1.2's after you crack the box on them. Pin/Blade, the original SL-2000's were stamped 1.2, and the crossover has 1.2 stamps on them as well.

Scott

BobMcG

Could it be another Polk transition speaker?

The crossover board is the same as the one used in the 2.3 with a few additional points on the board being used that are empty on the 2.3. I have the additional parts that are being used highlighted with pointers. The one pointer is aimed at the right-hand end of the wire connector plug to indicate that the connector is two places longer. (Of course.)

thehaens@cox.net

BobMcG wrote:

Could it be another Polk transition speaker?

The crossover board is the same as the one used in the 2.3 with a few additional points on the board being used that are empty on the 2.3. I have the additional parts that are being used highlighted with pointers. The one pointer is aimed at the right-hand end of the wire connector plug to indicate that the connector is two places longer. (Of course.)

Interesting observation, I remember looking at a thread not to long ago by HTrookie who was upgrading his TL's, which looks really similiar (exact) to the one I pulled. I am going to pull this one on saturday, and take it along with me up to my other buddy's house, he has some TL's (at least I hope they are), who knows? I just know he has the right drivers, tweeters, and IC, but I haven't pulled his x-over yet. If he has a 1.2 or SRS Crossover, I'm going to the police to file a complaint.:D

Scott

thehaens@cox.net

Woops....double post......

schwarcw

Scott, This looks like the SRS series crossover board to me. So you are saying that you have TL speaks and cabinent, but the SRS crossover? If so, the roll of values won't match the speakers since they are different than the TL's. How different I don't know. I'm sure one of the guys on here can tell you. I do have a TL owner's manual with the info somewhere, I'll look.

thehaens@cox.net

Carl

Take a look at Fig 4. The SRS Crossover is much, much larger than the TL's...

Scott

http://www.polkaudio.com/forums/showthread.php?t=19053

What I think we have here is a 1.2TL Box, Some Sl2000 Tweets, w/ a TL crossover....one would think OK easy, someone just put some 2K tweets in them. True....but the dates on the parts has me purplexed..

schwarcw

Hi Scott! I would say the post referenced was the TL board. As Bob pointed out, the SRS-2's, SRS-2.3 and SRS used the same board. They had more or less coils, caps and resistors depending on the model of SRS. My SRS 2.3 board looks identical except that you have more caps, coils, conncetors, etc. I had the board naked during my crossover mods and I could see the SRS components labeled on the board. If you have SL2000 tweets, I think you have SRS's in a TL cabinent. What are the numbers of your drivers?

BobMcG

By looking back at Raife's work, the crossover is similar to the 1.2TL he shows modified in fig-4. Once again, like the picture of the one you posted it appears use the same PC board as it's foundation as my 2.3s.

Is yours a 1.2 or 1.2TL crossover? I can't tell you.

schwarcw

Interesting. I suggest that you contact Ken at Polk Customer Service. Maybe he can shed some light on this puzzle.

Carl

dorokusai

He has been emailed.

thehaens@cox.net

schwarcw wrote:

Hi Scott! . If you have SL2000 tweets, I think you have SRS's in a TL cabinent. What are the numbers of your drivers?

They have the 6511 and 6503's, which were the same in both the 1.2 and the 1.2TL's. I will get to the bottom of this eventually. With some forum help as well as pulling apart all 3 1.2's. And comparing the cabinet w/ the known 1.2's to the others.

Scott

thehaens@cox.net

BobMcG wrote:

By looking back at Raife's work, the crossover is similar to the 1.2TL he shows modified in fig-4. Once again, like the picture of the one you posted it appears use the same PC board as it's foundation as my 2.3s.

Is yours a 1.2 or 1.2TL crossover? I can't tell you.

Bob - thanks for posting, their is a radical difference between the 1.2TL crossover, and the SRS, and SRS 1.2 Crossover. When I pulled the above pictured crossover out, I was shocked that it was so much smaller than the other crossovers that I have encountered in the 1.2's or SRS's. So naturally I logged in right away on the forum to see if there were others posted, (pics) and sure enough the one that Raife has looks the same.

I still haven't gotten an email back from Ken yet, but will call tomorrow time permitting to ask him about this..

Scott

puunda

Every Polk XO I've seen has a part number on it. Of course the XO could've easily been changed with an incorrect one at some stage.

[Deleted User]

Hello Guys,
I've forwarded this to Stu Lumsden, head of engineering.
Regards, Ken

BobMcG

Any verdict yet?

soupbone

I haven't posted here in a long time. I was helped out by the other members of this forum many times, so I'll try to return some of what I have learned from the guys here. I think that the problem you have is a very simple one. I also owned a pair of 1.2s that were wired wrong. The diagram on the back did not match the set up on the binding posts. Red and black were reversed. I had no SDA effect at all. After a series of ?? to polk cust service, the forum,:) testing and opening up the speakers to see that all the driver #'s matched up... we discovered they were wired out of phase. A very simple fix..reverse the red and black plasitc binding post caps. It didn't match the diagram...but so what..I had SDA MAGIC. The poor guy I purchased them from never really heard what these fine speakers can do. I talked to POLK PAUL about it and he said in the late 80's they were pumping out so many speakers that some problems were bound to happen. The 1.2 and the 1.2tl crossovers were the same except for some values in the tweeter caps. I don't think you could tell the difference between them if the stickers came off. The original SRS was a different animal altogether..it took up the entire crossover board..it was huge. The 1.2 board was simplified and had less than half of the components on it. Then they added the TL version that just changed the tweeters and the cap values but kept the same board. I think at that same time they also added a bass brace on the inside of the back wall of the cabinet about 16 inches up from the bottom. You can see it if you remove the radiator...it runs along the entire back wall horizontally and is about 3 inches wide. Early versions of the 1.2tl's simply said 1.2 on the back. So what I think you have here are a pair of 1.2's that simply don't match wiring diagram. The 1.2 and 1.2tl crossovers look identical. Look for that bass brace I mentioned..if it has the brace then they are 1.2tl"s with the wrong tweets.......no brace and you have a pair of the 1.2s' non tl version. Hope this helps. Soupbone

F1nut

Hi Tom, good to see you back.

thehaens@cox.net

soupbone wrote:

I haven't posted here in a long time. I was helped out by the other members of this forum many times, so I'll try to return some of what I have learned from the guys here. I think that the problem you have is a very simple one. I also owned a pair of 1.2s that were wired wrong. The diagram on the back did not match the set up on the binding posts. Red and black were reversed. I had no SDA effect at all. After a series of ?? to polk cust service, the forum,:) testing and opening up the speakers to see that all the driver #'s matched up... we discovered they were wired out of phase. A very simple fix..reverse the red and black plasitc binding post caps. It didn't match the diagram...but so what..I had SDA MAGIC. The poor guy I purchased them from never really heard what these fine speakers can do. I talked to POLK PAUL about it and he said in the late 80's they were pumping out so many speakers that some problems were bound to happen. The 1.2 and the 1.2tl crossovers were the same except for some values in the tweeter caps. I don't think you could tell the difference between them if the stickers came off. The original SRS was a different animal altogether..it took up the entire crossover board..it was huge. The 1.2 board was simplified and had less than half of the components on it. Then they added the TL version that just changed the tweeters and the cap values but kept the same board. I think at that same time they also added a bass brace on the inside of the back wall of the cabinet about 16 inches up from the bottom. You can see it if you remove the radiator...it runs along the entire back wall horizontally and is about 3 inches wide. Early versions of the 1.2tl's simply said 1.2 on the back. So what I think you have here are a pair of 1.2's that simply don't match wiring diagram. The 1.2 and 1.2tl crossovers look identical. Look for that bass brace I mentioned..if it has the brace then they are 1.2tl"s with the wrong tweets.......no brace and you have a pair of the 1.2s' non tl version. Hope this helps. Soupbone

Wow, this brings up some more questions on my speakers. I have the BASS Brace, have the 1.2 Drivers, had the 2000 tweets, that have been since upgraded to the silks. Have the pin/blade IC, and have the large crossover. My damn dig. camera is in the shop so I can't take pics, but out of the three SRS's we have in the neighborhood this is what we have....

Mine- SRS 1.2
Pin/Blade
SL2000
6503 Stereo Drivers
6511 Dim. Drivers
Large Crossover edit: Mine actually has the smaller crossover.......

Ray- SRS 1.2TL
Pin Blade
SL3000
6503 Stereo
6511 Dim
Small Crossover

Ralph-SRS 1.2(?)
Pin/Blade
SL2000
6503 Stereo
6511 Dim
Small Crossover

All three cabinets have the Bass Brace Screw on the back.

All in all they sound fantastic, mine seem to have a bit more bass than the others, but I have a more neutral room than the others.

Still Confused...

Scott

schwarcw

I still think you have the 1.2's with the large crossover. Have you got a reply from Polk?

Carl

thehaens@cox.net

schwarcw wrote:

I still think you have the 1.2's with the large crossover. Have you got a reply from Polk?

Carl

Nope, not yet, but no worries I/we are still enjoying them. Just curious as to what we have. I thought the 1.2's had the large crossover, but apparently I was wrong in that assumption, and if Ralph indeed has TL's then we ordered the wrong Silk Tweets, as we ordered the replacements for the SL2000's which were the stock tweets that were in them when we got em'....unfortunately I didn't open up the crossover to see what he had in there.
Scott

soupbone

Scott,
Don't confuse the bass brace screw on the back of the cabinet with the one on the inside. The TL version had an extra wooden brace on the inside of the cabinet. You have to remove the passive radiator to see it. You may also be able to see it if you remove the crossover plate. It is 10 inches up from the bottom of the cabinet (my previous post I listed it at 16) 3 inches wide and runs the entire width of the cabinet.

Ralph has 1.2's
Ray has 1.2tl's

I'm interested to know if you have the internal brace. With everything else you have described....I would have to say that you don't have the brace. Which would mean at one time they where 1.2's. Someone may have switched the crossovers. Your crossover should also be small. I'd like to see a picture of your crossover. Hope this helps...Soupbone

thehaens@cox.net

Soupbone...

I'll get pix as soon as my digi camera gets back to me....of all the insides, as well as the crossovers. etc.....

Thanks

But the crossover I have is easily three times longer than the one I posted a pic of above......so I may very well have the SRS crossover in mine, it may have been replaced. I know it has 1.2 stamped on the crossover, and all my tweeters had 1.2 stamped on them, furthermore from what I have seen from other posts of SRS owners the cabinet of the SRS didn't have the bass brace screw on the back....

Scott

polkgrinder

Let me help you out a bit. Can you identify the value of a capacitor? I can help you identify the Caps that will filter your drivers (bass).

Note, the 1.2TL's wired their tweets with positive lead to negative terminal due to a reverse of phase. SL2000 verses SL3000 really won't tell you much with early model 1.2TL's.

1) If you have two 130uF caps wired in parallel, then it is a SDA SRS cross over. You will need a common grounded amp for this baby.

2) The largest caps on SDA 1.2 will have a 20uF and 40uF capacitors. Tweets are wired normally.

3) The largest caps on SDA 1.2TL are 13.5uF and 27uF capacitors. The tweets are wired backwards too as previously stated.

The inductor coils for the drivers on the SDA are the largest at 2.75mH each verses the smaller coils at 1.0mH and 2.0mH for the TL. The 1.2 is in between.

I have schematics of the three models if you need.

steve

thehaens@cox.net

soupbone wrote:

Scott,
Don't confuse the bass brace screw on the back of the cabinet with the one on the inside. The TL version had an extra wooden brace on the inside of the cabinet. You have to remove the passive radiator to see it. You may also be able to see it if you remove the crossover plate. It is 10 inches up from the bottom of the cabinet (my previous post I listed it at 16) 3 inches wide and runs the entire width of the cabinet.

Ralph has 1.2's
Ray has 1.2tl's

I'm interested to know if you have the internal brace. With everything else you have described....I would have to say that you don't have the brace. Which would mean at one time they where 1.2's. Someone may have switched the crossovers. Your crossover should also be small. I'd like to see a picture of your crossover. Hope this helps...Soupbone

Finally got the camera back, here is a few pics of my speakers, my apologies for the past statements regarding my crossover. I don't have the large crossover. I must of spent to much time on this forum looking at Darqueknights photos of the rebuild project. There is a brace, actually a couple running up the middle of my cabinet. The pic with the wires showing is right behind the crossover, and the other pic of the wooden brace is approx 8 inches above.

Scott

schwarcw

You have the 1.2's! This is consistent with what Steve described!

Carl