CRS+ crossover miswired?

jimbo1421

Hello,

Last week I installed blade/blade receptacles in my CRS+ terminal cups and now have a proper interconnect. Following the procedures in the SDA Quick Troubleshooting.pdf‎ all the meter tests checked out. Listening test #2 flunked, however. That's the one where you disconnect the negative (black) leads from the terminal cup. With the balance set all the way left or right you should only here the dimensional drivers. Instead I could hear all of the drivers. Not right.

Thinking I may have switched some leads inside, I took both speakers apart again. All of my connections were correct and the connections between the terminal cup, the crossover and the drivers look right as well, according to the schematic. However, there are two black wires that run from points 'P' and 'R' on the circuit board to spade terminal connectors on the large coil (is this called an inductor?). They both go to the same relative positions, that is, 'P' to right connector, 'R' to left, on both crossovers. Is this right? I am not very good at reading schematics. The right crossover showed signs of tampering so these connections could have been mixed up.

If this is not the problem, then where else should I look.

Jim

F1nut

Those leads are correct, actually it doesn't matter which one goes where.

Last week I installed blade/blade receptacles in my CRS+ terminal cups

Why and where did you get them? 10 to 1, your problem involves something you did changing them.

jimbo1421

Why not? They are the Cinch connectors that match the blade/blade cable from my SDA1Bs and they fit the holes in the terminal cup. I got them from Mouser. I soldered the blue (SDA) wire to the narrow blade socket and the white neutral to the wide blade socket. I coated the receptacle with hot melt glue to seal it. There is not much change to the sound of them from when I was using an RCA cable, and I had not run the Quick Tests before replacing the sockets. I just knew that the extended soundstage typical of SDAs was missing and still is.

Jim

F1nut

I soldered the blue (SDA) wire to the narrow blade socket and the white neutral to the wide blade socket.

The right speaker should have the blue wire connected to the large blade socket, white wire to small. The left speaker should have the black wire connected to the small and the white wire to the large. The actual cable should be large blade to large, small to small.

Why not?

That answer isn't helping me help you. Was there something wrong with the originals or did you simply do it to do it?

jimbo1421

I appreciate your help, F1nut.
These CRS+ were missing the IC cable, the pin/blade type. Since these connectors are no longer made I saw no reason not to use the blade/blade connector sockets used by the earlier generations of SDAs, using the narrow blade in place of the pin. I could also borrow the IC cable from my SDA1Bs until I make up a new one.

According to this circuit diagram, SDA CRS+ 1989 Sch.pdf‎ (which matches what I see inside my CRS+) there are only blue and white wires to each IC. I soldered the blue wires to the narrow blade sockets, the white wires to the wide blade socket. The blue wire (part of a bundle with a snap on connector) goes to a point on the circuit board labeled 'IC'. The white wire goes to negative binding post. There are no black wires going to the IC, just to the positive binding post.

Does this clarify my situation?

Jim

F1nut

Yes it does, thanks. I didn't realize your CRS+'s were originally pin/blade, so you have the wires in the right place.

What are the signs of tampering?

jimbo1421

F1nut wrote: »

Yes it does, thanks. I didn't realize your CRS+'s were originally pin/blade, so you have the wires in the right place.

What are the signs of tampering?

Good, the wiring is right then. As for tampering, on the right crossover, the circuit board had broken loose from the coil and had been secured back in place with zip ties wrapped around the whole assembly. That is why I thought that those two wires might have been mixed up. The original snap in standoffs were trashed and I replaced them with nylon standoffs and screws. Also many screw holes for the drivers, terminal cup and PR were messed up. The seller was unaware of the SDA technology and I thought he or some other owner might have rewired them so that the dimensional driver functioned as a stereo driver.

So I am still stuck with the mystery of why the #2 listening test failed. (See post #1). Is this test valid on the CRS+? While these CRS+ sound nice, the soundstage doesn't extend beyond the outside of the speakers by much.

Jim

F1nut

Are the +/- binding posts in the right place? As the red and black posts unscrew all the way, it's known that some folks swap them by mistake. Looking from the back, the red post should be on the left. Also, are the drivers in their proper location? Are the black or blue leads connected to the marked red dot terminals on the drivers?

jimbo1421

F1nut wrote: »

Are the +/- binding posts in the right place? As the red and black posts unscrew all the way, it's known that some folks swap them by mistake. Looking from the back, the red post should be on the left. Also, are the drivers in their proper location? Are the black or blue leads connected to the marked red dot terminals on the drivers?

Yes to all questions. The dimensional drivers (MW6511) are always to the outside of the cabinets.

Could the polyswitch cause this issue?

Jim

gimpod

No, they are for the tweeters only.

Can you post a pic of both the top and bottom of the crossover, it might help alot.

Sad but true some idiots wire the drivers together or screw up the crossovers so all the drives work with out the IC.

Keep at it and we'll get it figured out.

jimbo1421

Thanks, gimpod. I can post some pics in a few days after I get the film developed and scanned.

Jim

F1nut

Yep, pics are needed at this point.

jimbo1421

F1nut wrote: »

Yep, pics are needed at this point.

Well, after a couple of computer meltdowns I finally got to scanning and processing these negatives. The right crossover is the one that came loose and was zip-tied back together. I see no sign of any resoldering or that the leads have been re-routed, but maybe someone else can tell if something is amiss that could cause these CRS+ to flunk the listening test that I described in my first post.

Jim

Malbec

Hi Jimbo, just lurking here trying to learn a few things. When you stated you could hear all the drivers, does that include the tweeters?

Robert

jimbo1421

Hi Robert,

I can't remember, since it has been over a month since that test. Since I said I could hear all of the drivers, I think that meant tweeters, also.

Jim

F1nut

This new IC cable that you made, did you connect a wire from wide blade to wide blade and narrow to narrow?

jimbo1421

Thanks for your continued interest, F1nut.

I have not yet made up a new IC. I borrowed the cable from my SDA-1B. I did check the continuity on that cable and wide blade is continuous with wide and narrow to narrow. On the replacement sockets, narrow blades replaced the pins.

Do you see anything wrong in the pictures?

Jim

TennMan

jimbo1421 wrote: »

Thanks for your continued interest, F1nut.

I have not yet made up a new IC. I borrowed the cable from my SDA-1B. I did check the continuity on that cable and wide blade is continuous with wide and narrow to narrow. On the replacement sockets, narrow blades replaced the pins.

Do you see anything wrong in the pictures?

Jim

I have a pair of pin/blade CRS+ and my crossover looks identical to yours. I can't see a problem when viewing the photos other than the connector on the inside of the binding cup looks different. I guess that is from the work you did.

I'm wondering if the IC cable(s) you are using is configured correctly. You say that the cable you are using has continuity between the wide blades on each end of the cable... and you say you have continuity between the narrow blades on each end of the cable.

I have the original IC pin/blade cable for my CRS+. There is continuity between the pins on each end of the cable. There is NO continuity between the blades on each end of the cable. I questioned this when I first got my CRS+ and was told by more that one member here that is the way the cable should be. I was also told the blade was only used to give strength to the connection where it plugs in. Maybe the extra connector with continuity in your cable is the cause of your problems.

You should remove your cables and run a length of heavy speaker wire between the terminals in the connector with the blue wires to see if the speakers start working correctly.

jimbo1421

Thanks, TennMan. I will give that a try. Do you or anyone have any further suggestions to try before I put these CRS+ back together?

Jim

F1nut

STOP, do not use the blade/blade cable again. You cannot have a connection between the negative terminals of the SDA connection unless you use the AI-1. I don't know if that is the solution to your issues, but it sure as hell will make an issue.

F1nut

As for the pictures, I see way too much hot glue on the small inductors and some really sloppy hot glue work elsewhere, but that's not going to cause an SDA issue. In this pic it looks like there is no solder on the one end of the 27uF cap. It could just be the angle, but please verify.

http://www.polkaudio.com/forums/attachment.php?attachmentid=67004&d=1330386851

gimpod

F1nut wrote: »

As for the pictures, I see way too much hot glue on the small inductors and some really sloppy hot glue work elsewhere, but that's not going to cause an SDA issue. In this pic it looks like there is no solder on the one end of the 40uF cap. It could just be the angle, but please verify.

http://www.polkaudio.com/forums/attachment.php?attachmentid=67004&d=1330386851

Ditto (fixed it for ya ), Did you add all that hot glue or did they come that way, I've never seen Polk use hot glue on the caps before if you didn't do it that might be an indication that someone's been tinkering with them. Also what value are those black caps between the inductor and the 4 pin connector (I've never seen Polk use a black one there usually blue), it should be a 40uF cap. Also it would have been more helpful if you had posted pics of the bottom of the boards without that big inductor attached.

The white wire that's connected from the socket to the negative binding post was only done so you could use the AI-1 IC and was NOT suppose to be used to connect the negative binding posts on both speakers together. So just disconnect it or make a single wire IC connecting the small blades together only.

F1nut

Ummm...yeah the 40uF. Thanks Tony!

F1nut

Good call on those black caps, Tony. I hadn't looked at the one pic that clearly shows 12K printed on it.

pitdogg2

May i ask what affect the hot glue may do? When i recapped my SDA boards older 2 board style Polk had hot glued the snot out of everything except resistors. I left what was on the inductors then of course used some on the caps to hold in place like Polk did but not near as much.
Thanks

F1nut

pitdogg2 wrote: »

May i ask what affect the hot glue may do? When i recapped my SDA boards older 2 board style Polk had hot glued the snot out of everything except resistors. I left what was on the inductors then of course used some on the caps to hold in place like Polk did but not near as much.
Thanks

Nothing really, but the job on jimbo1421's boards is extremely sloppy and all that glue on the small inductors would make them difficult to remove without damage.

jimbo1421

The only hot melt glue that I did was on the replacement IC socket for sealing purposes. My toy-like glue gun leaves as much hair as is on the inductors so maybe that is an amateur job.

The black capacitors are turned with the specs facing the board so I will have to remove them to get their values.

I did not realize that the IC from my SDA-1B was incompatible with the CRS+. Thank you both for that tip. When I reassemble I will test with a single wire IC.

Jim

[Deleted User]

Hello Jim,
On the CRS+ the connections to the back of the input cup are reversed for the left and right speakers. For the right channel speaker the blue wire is the "wide" blade connection, the white wire is the "narrow" blade connection. For the left channel speaker the white wire is the "wide" blade connection and the black wire is the "narrow" blade connection.
Regards, Ken

F1nut

Ken, His CRS+'s are actually the pin/blade version. He decided to change the the pin/blade sockets in the speakers to blade/blade so that he could use the blade/blade cable, which as it turns out, he cannot use.

jimbo1421

Kenneth Swauger wrote: »

Hello Jim,
On the CRS+ the connections to the back of the input cup are reversed for the left and right speakers. For the right channel speaker the blue wire is the "wide" blade connection, the white wire is the "narrow" blade connection. For the left channel speaker the white wire is the "wide" blade connection and the black wire is the "narrow" blade connection.
Regards, Ken

Hi Ken,

Thanks for looking at this problem, but now I am confused, since your description doesn't seem to match the wiring as I found it or the schematic. I.e, my left IC has blue and white wires, not black and white. Did you note that I had replaced the pin/blade socket in the input cup with a blade/blade socket? I substituted the narrow blade for the pin. These CRS+ were missing the IC and the plugs to make one are not available.

Regards,
Jim

Malbec

Hey Jimbo, Ken's discription matches the '86 shcematic.