SDA SRS Problem with dimensional array.
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gregmoyers
Posts: 140
I have no sound from left dimensional array when I pan all the way right.
Drivers good, they all play when balance is center. Just no right channel info is playing on left array.
Cable good
All wiring checks out.
Someone please help with what could be blown on either crossover to cause this.
PLEASE.
Drivers good, they all play when balance is center. Just no right channel info is playing on left array.
Cable good
All wiring checks out.
Someone please help with what could be blown on either crossover to cause this.
PLEASE.
Comments
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Never mind. You said that you fixed this in another thread, but didn't bother to update this thread.
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I don’t think that’s the case. He describes this as “another problem” in that other thread: https://forum.polkaudio.com/discussion/comment/2717818/#Comment_2717818
An example of why multiple posts/threads on the same topic are generally a bad idea.
EDIT: Oh, there are actually 2 other threads (https://forum.polkaudio.com/discussion/198088/need-help-with-sda-srs-no-dimensional-array-output-one-channel).
Good luck! 😬Brian
One-owner Polk Audio RTA 15TL speakers refreshed w/ Sonicap, Vishay/Mills and Cardas components by "pitdogg2," "xschop" billet tweeter plates and BH5 | Stereo REL Acoustics T/5x subwoofers w/ Bassline Blue cables | Rogue Audio Cronus Magnum III integrated tube amp | Technics SL-1210G turntable w/ Ortofon 2M Black LVB 250 MM cart | Sony CDP-508ESD CD player (as a transport) | LampizatOr Baltic 4 tube DAC | Nordost & DH Labs cables/interconnects | APC H15 Power Conditioner | GIK Acoustics room treatments | Degritter RCM -
Sorry. Im new to this forum and it is difficult to understand where to post what. I’m just reaching out to whoever I can wherever I can. Where can I post an update on where my problem is at now?
I fixed the new cable wiring issue and now it is not working again. -
Maybe this will help, you stated you made new cable and cabinet connections.
Blade/blade cable is a straight cable which means Wire big Blade to big Blade Small to small straight through. SO speakon should be 1+ to 1+ Big or small and 1- to 1- NOT 1+ to 1-
The switch took place in the cabinet SO not knowing the actual cable colors I'll use this as a FOR INSTANCE ONLY
RIGHT speaker had Blue cable to big Blade and Green cable to Small blade
LEFT speaker had Blue cable to Small blade and Green cable to BIG blade
SO your new speakeon connection SHOULD have been
RIGHT speaker Blue cable to 1+ and Green cable to 1-
LEFT speaker Blue to 1- and Green to 1+
Follow?
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Yes thanks, the cable and Speakon jacks wiring is corrected and everything was working. I shut it down, took the left crossover out to fix a broken lead on polyswitch, which was successful, then replaced the crossover and and now the dimensional array on the left is dead. I did not touch the cable, jacks or anything thing else. I guess I will remove the crossover again and inspect all the wiring to the board and inductors. If all ok it has to be on the board?
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Do all of your drivers ohm out/not shorted?Don't take experimental gene therapies from known eugenicists.
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Don't know if this means the threshold s500 is not common ground -
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All the drivers are fine. I test with sda cable off and all drivers work fine. When I plug the cable in and check the dimensional left channel array ( the outer 4 drivers) by turning balance all the way to the right channel there is zero sound from those left drivers.
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Not saying this happened with yours but...
When I split my Gen 3 crossover to un-solder my poly, to install a bypass, the inductor on the left, by the 120uf caps, had broken one of the legs off on the PCB. -
If the SDA Cable is removed with the balance knob centered, the left channel SDA drivers would still play left-channel bass via the SDA inductor. They would ALSO vibrate in sympathy with the left-channel stereo drivers just like the bassive radiator. You would still hear left-channel information from those drivers; although it would be bass-heavy. There would be no right-channel SDA out-of-polarity signal due to the disconnected SDA cable. This should be noticeable as there'd be no "SDA effect" on the left speaker cabinet. But as we all know, speaker position and room acoustics can mess with the SDA effect. So maybe this isn't as obvious as it should be.gregmoyers wrote: »All the drivers are fine. I test with sda cable off and all drivers work fine.
Which makes me think that those drivers ARE NOT working, they're merely vibrating with the stereo drivers. When the left channel stereo drivers quit working because of the balance knob being turned fully "right", there's no pressure-pulses in the left cabinet to jiggle the cones of the left SDA drivers. It's possible, but enormously unlikely that all four drivers have failed. More likely, they're just not receiving any electrical signal due to a broken wire, or failed solder-joint, or cracked printed-circuit trace.gregmoyers wrote: »When I plug the cable in and check the dimensional left channel array ( the outer 4 drivers) by turning balance all the way to the right channel there is zero sound from those left drivers.
I would be looking REAL HARD at the SDA inductor circuit (not only where the SDA inductor leads join the circuit board, but that's a good start.) I have not dug-up the schematic...but I'm thinking a simple continuity test from speaker "black" terminal to the pin socket, or to the proper blade socket of the SDA cable should show a break in the circuit. Perhaps I'm wrong. Can't remember if the SDA capacitors would block the signal from the continuity (Ohm-) meter
Post edited by Schurkey on -
Don't know if this means the threshold s500 is not common ground
"Do not allow amplifier outputs to common between channels"
Sounds like a non-common-ground amp to me. But that doesn't explain why you aren't he isn't having problems when the balance knob is turned the other way (to the left.)
Good catch, by the way. Thanks for that. -
...and...refresh my memory...I have zero experience but a vague memory from post(s) on this forum:
Weren't there problems with (some of?) the original SDA SRS "big-boy" speakers, where the red and black plastic nuts on the binding posts were reversed? Or the red and black binding posts were mis-wired? Am I thinking of the right speakers that were affected this way?
Wild Guess with no evidence: When he gets this figured out, he's going to hear proper SDA for the first time. We'll hear his jaw drop from where we are. -
I’ve had these from day one new original owner. I know what they are and how they sound. I also know how they work. I have listened to these speakers in many rooms and many different amps. This is not reversed polarity at the binding posts. It’s not the IC cable. Its not the drivers. Something is wrong on the xO board. Please stop talking ABOUT me and talk TO me if you have any constructive input.
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As others, trying to help with diagnosing....
Do you have another amp to try? -
See my second post in this thread. Five posts up from this one.gregmoyers wrote: »talk TO me if you have any constructive input.
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Especially, the last paragraph there. I'm not really sure who got on his nerves here.Brian
One-owner Polk Audio RTA 15TL speakers refreshed w/ Sonicap, Vishay/Mills and Cardas components by "pitdogg2," "xschop" billet tweeter plates and BH5 | Stereo REL Acoustics T/5x subwoofers w/ Bassline Blue cables | Rogue Audio Cronus Magnum III integrated tube amp | Technics SL-1210G turntable w/ Ortofon 2M Black LVB 250 MM cart | Sony CDP-508ESD CD player (as a transport) | LampizatOr Baltic 4 tube DAC | Nordost & DH Labs cables/interconnects | APC H15 Power Conditioner | GIK Acoustics room treatments | Degritter RCM -
Me, I expect.
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Thank you Schurkey. AlI saw was you sounding like Ive never heard these working right. I’ve been listening to them for 30 years.
They are my babies. Now they are down and I appreciate all your input. I will let you know when I find what the issue is. I think it has to be on the board I do have a PA7 that I am going to hook up when I get them all back together. It’s got to be SOMETHING. -
[img]https://us.v-cdn.net/5021930/uploads/editor/eq/g7jluxw8k 821.png[/img]
So here is the wiring diagram’s and a picture of each binding cup. All wiring to and from the crossover’s is good. All drivers are good. What could be wrong on this pretty simple board that I’m not seeing? -
Did you check all 6 of the SDA Wiring Checkpoints for both L and R speaker, as shown in the SDA Handbook?George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
What did you use the seal the speakon socket? Black on one white on the other?
When this particular problem is solved I'd recommend sealing up all the binding posts with hot melt glue, wouldn't hurt to also do the speakon socket as well. -
Thanks for posting the schematic. Interconnect socket "A" is the one that has very low resistance (almost none) to the low-frequency "Red" or "+" binding post. I don't SEE a connection between one of the Speakon cables and the "red" binding post...but it might be made somewhere "upstream" and out-of-the view of the camera when the photos were taken.
The capacitors for the SDA are NOT going to block continuity from Interconnect socket "A" (which is different between the two speaker cabinets) and the "black" low-frequency speaker wire binding post on each cabinet. Connect your tester (Ohmmeter) to those two points. You'd be testing:
1. The SDA connector which in this case is Speakon.
2. The 2.75mH inductor in-line with the four drivers
3. The four drivers--although an open in any one driver, or certain combinations of two drivers, would still show continuity (but higher resistance) through the remaining drivers.
4. The 16mH SDA inductor, and
5. The wire harness that connects these items.
Test BOTH cabinets, compare results. Should be really close to each other.
I don't know what the resistance figure should be--no doubt something of a range rather than a single figure due to production tolerances. Continuity would be mandatory, so "infinite" or even extremely high resistance would be a "fail". Drivers are in a series/parallel circuit, plus the resistance of the big and little inductors...if your ohmmeter reads more than maybe 20 ohms, something's wrong. I think. If this is covered in the resistance tests in the SDA Handbook, there'll be a more-reliable resistance spec given. I'm just guessing.
It wouldn't test the two 130uF SDA capacitors, or the 20uF bypass cap. If the 20uF cap is shorted, your resistance measurement from "A" to "black" would be much lower than expected. I specifically recommend testing the 260uF (paired 130uF) SDA caps, which would have to be done in a different process than testing from "A" to "black". I think you'd need an actual capacitance tester, a typical multimeter won't work. At least verify that the wires and solder connections at the two 130uF caps haven't broken or failed.
Post edited by Schurkey on -
Are A and B on your IC/speakons wired correct?
The Green wire looks reversed between top and bottom pic.Don't take experimental gene therapies from known eugenicists. -
Are A and B on your IC/speakons wired correct?
The Green wire looks reversed between top and bottom pic.
https://us.v-cdn.net/5021930/uploads/attachments/1/8/5/1/1/26685.pdf
I believe they're supposed to be reversed. See note on drawing by "SDA Cable Jack". -
Are A and B on your IC/speakons wired correct?
The Green wire looks reversed between top and bottom pic.
https://us.v-cdn.net/5021930/uploads/attachments/1/8/5/1/1/26685.pdf
I believe they're supposed to be reversed. See note on drawing by "SDA Cable Jack".
Yes that is correct the switch is at the socket in all blade/blade speakers.
I explained the wiring of the socket and wire in this post above. -
Insightful but confusing.
So electrically, should look like this?
Post edited by xschop onDon't take experimental gene therapies from known eugenicists. -
Thank you everyone!
Im gonna have a steak and a beer, walk the dogs and hit it tomorrow am. Cant wait to nail this thing. In the meantime they sound pretty good without the cable. But not the same. Thanks again. Great info. -
Yes. Sort of. In your illustration, it looks like the "change" is done in the SDA cable, when it's actually done by reversing wires at the SDA connector as you noticed. But "electrically--functionally" your connections result in the correct transmission of signal from one cabinet to the other. What is the low-frequency "+" signal in one cabinet is the filtered signal delivered to the negative (-) side of the SDA speaker drivers in the other cabinet.Insightful but confusing.
So electrically, should look like this?
There's a connection from the Low Frequency "Red" "+" binding post to the "A" connection at the SDA cable socket (Speakon in this case, big 'n' little blades originally) in each cabinet. This also supplies low-frequency information to the SDA drivers in the SAME speaker cabinet, in-phase, and frequency-filtered by the inductors and bypass cap, adding to the bass volume. But that same signal without the filtering is fed to the negative side of the SDA drivers in the opposite cabinet, filtered in that opposite cabinet first by the SDA capacitors and then the SDA inductor. Resulting in a backwards-polarity force on the SDA drivers, causing the SDA crosstalk cancellation effect. Thus the SDA drivers reinforce same-channel bass, but produce the crosstalk cancellation as well.
The later, pin-blade SDA speakers use a simplified system with a single active conductor in the SDA cable instead of two active connectors--one right-to-left, and one left-to-right in the blade/blade system.Post edited by Schurkey on -
Very good explanation.
But do all 8 drivers play with the cable removed? I always thought they did.
So since my L channel sda drivers have nothing when I pan to the R then the problem could be in the R crossover circuit not producing the crosstalk cancellation signal. I am 100% sure there is nothing wrong with the Speakon cable and sockets or in the cabinet harness or drivers. What part of the circuit could have failed in the R XO to not send the signall? Both 130uF caps is all I see.
Or am I wrong in thinking all 8 drivers work when the cable is removed? Because when the cable is removed both cabinets perform perfectly.
