SDA 1A....left channel has an issue

marly421

Ken, maybe your listening in? And of course everyone else of the Polk gang that know a bit about SDA speakers and primarily my newly purchased SDA 1A’s, please jump in.

I had another tread going [good one too] and got lot’s of excellent info there. I’m not new to Polk Audio but the SDA’s are a different cup of tea.

I search the forum and found Ken had already answered the question about positive and negative on the speaker itself: plus the negative, the white, black, blue, green wires and such.

After all that, my left cabinet still seems to have a problem. The stereo drivers work fine but the SDA drivers do not. In fact if I unplug the SDA cable the entire speaker stops in the left cabinet.

Was wondering what we know about the SDA cable? We put a multi-meter on each of the blades to check if the cable is internally damage [using the Ohm scale of the meter] in some way but all we get is the meter jumping from zero [0] to off the scale and can't get a good reading on either pin.

We had though the wire went completely through and should give us a near zero reading but either the cable is damage or the meter or we don't know what to look for.

Of course, why if the SDA cable is removed why would the entire speaker shutdown? The right side speaker sound good and everything seem to be working fine there.

Any help would be greatly appreciated,

Marlene

PS I pulled all the drivers and part of the x-over with the binding posts attached and checked all connection and wires and used the meter to double check everything I could get my hands on. Nothing jump up and bite me. I’m really at a lose.

Tour2ma

May not be an issue, but just as a precaution... What amp are you using?

Originally posted by marly421
The stereo drivers work fine but the SDA drivers do not. In fact if I unplug the SDA cable the entire speaker stops in the left cabinet.

With the SDA cable in place is there any stereo image, or is it a monaural (centered) image?

The direct stereo drivers should always run off of the amp. That your left ch's stereo drivers are getting a signal from the SDA cable, and not the amp, says to me the internal wiring is crossed. I'm not sure what it is saying about where the amp's direct left ch signal is going.

Is the right channel OK? Direct and SDA? If yes, compare its internal wiring to the left's, and see if there's a difference you can spot other than the connection to the SDA connection (I believe these should actually be opposite).

Was wondering what we know about the SDA cable? We put a multi-meter on each of the blades to check if the cable is internally damage [using the Ohm scale of the meter] in some way but all we get is the meter jumping from zero [0] to off the scale and can't get a good reading on either pin.

I do't suspect this is the issue, but...

Set your multimeter, or Volt-Ohm-Meter (VOM), as I refer to it, to it's highest ohms range. Test the meter by touching it's two leads together. The reading should fall to zero.

Next touch one lead to your hand and the second to your other hand. Note that while the reading does not fall to zero, it does fall. This is only to demonstrate that you can make the meter reading change by touching it, so be careful not to touch the leads or the SDA cable's blades during the tests to follow.

Touch one meter lead to one blade on the cable and the second lead to the other blade on the same end of the SDA cable. The reading should stay at the maximum.

Now working with both ends of the SDA cable put one VOM lead on the top blade at one end of the cable, and the second lead on the top clade of the other end. The reading should fall to zero. The same as above should occur, with leads on the cable two lower blades.

Let us know what you are seeing and what readings you got...

marly421

Thanks Tour2ma, I'm feeling really alone with these silly speakers and just about pulled all my hair out in the mean time.

May not be an issue, but just as a precaution... What amp are you using?

I'm trying to put a 'Vintage' stereo system together but that has stalled too. EBay and Audiogon have been my sources and it’s been terrible. Three Carver receivers [including the Carver 2000] sold as mint...worked like mint paddies for sure. Returned all and every seller claim it was working perfectly and look perfectly bah bah and bah!

What's the old joke: What are 10,000 eBay sellers laying on the bottom of the ocean called?

A start! Couldn't agree more. Sorry back to problem at hand.

Currently I’m using for testing purposes the 'Optimus Professional Series receiver STAV-3680'. Its rated 5x100 watts at .06 distort.

My next Vintage piece will be the 'Technics SA 5760 Receiver' rated at 205 watts into a 4Ohm load. Not here yet though.

Anyway I did switch the Lt - Rt speaker leads and the problem stayed right with the Lt channel speaker.

With the SDA cable in place is there any stereo image, or is it a monaural (centered) image?

To me it sounds Stereo.

The direct stereo drivers should always run off of the amp. That your left channels stereo drivers are getting a signal from the SDA cable, and not the amp, says to me the internal wiring is crossed. I'm not sure what it is saying about where the amp's direct left channel signal is going.

This is where its really driving me crazy...total of 14 speaker in the two cabinets and trying to keep tract of them and the wiring has turned my home into a 'Repair shop'. I've checked the wiring a number of times and all seem correct, I've put the meter to good use but I'm missing something or it’s simply hiding from me or maybe I'm simply stupid?

Is the right channel OK? Direct and SDA? If yes, compare its internal wiring to the left's, and see if there's a difference you can spot

Yes the Rt is direct and SDA.

working with both ends of the SDA cable put one VOM lead on the top blade at one end of the cable, and the second lead on the top blade of the other end. The reading should fall to zero. The same as above should occur, with leads on the cable two lower blades.

I have and did check [my meter is digital, Fluke model 73] the SDA cable. On this meter an open circuit is 'O.L' a closed circuit is 0.0 but that is impossible as the leads themselves carry 0.03 resistant. Anyway the SDA cable which I just buffed [the blades] to see if I could get a good reading this time.

I got good reading this time; big blade/big blade 0.06 small blade/small blade 0.07 and big/small blade 0.L or open circuit. Seem good.

So the problem is the wiring or components in the left cabinet, right?? I need a cup of coffee.

Marlene

PS BTW guess where I got these SDA 1A speakers? Read the joke above! Maybe I'm the joke here.

Tour2ma

First, you must be a lawyer to twist up that old joke...

And I asked about the amp to see if you were using a non-common ground model... I don't think you are, but you can check the resistance between the two negative terminals of whichever one you are using (with speakers disconnected) to be sure. Old SDA's require a common ground amp (or special interconnecting cable, the AI-1... (thanks, Jesse) ).

So where are we...
SDA cable is fine...
The Rt ch is fine...

Gotta be a Left ch issue... I’m just not familiar enough with SDA guts to take you any further.

Call Ken S. He will send you an SDA troubleshooting guide.

Good Luck…

F1nut

Hmmm.......do you have a schematic? If not, PM me your fax number and I'll send you one. The fact that you get no sound with the cable removed is very strange, which leads me to believe that the problem lies with the stereo drivers and not the SDA drivers. Just for the hell of it, swap the crossovers and report back.

On a side note, why mess a round with cheap vintage receivers, you need to feed those bad boys some real he-man power.

marly421

F1nut,

Hmmm.......do you have a schematic? If not, PM me your fax number and I'll send you one. The fact that you get no sound with the cable removed is very strange, which leads me to believe that the problem lies with the stereo drivers and not the SDA drivers. Just for the hell of it, swap the crossovers and report back.

I don't have any paperwork on these SDA's. Thanks but I have no fax, none of my friends or work uses it either. Do you have a scanner? $30 bucks can get you a new one that works just fine with Windows XP.

I've had the drivers out many times now but let me think on the x-over swap...

On first look the stereo x-over has leads for 4 drivers the SDA x-over has 2 driver leads...I think. Would it be useful to wire in another 2 set of leads on the SDA x-over to accommodate the 2 extra drivers?

I’ll look some more before I swear on a bible about all the leads. First lunch.

Marlene

PS Side Note:

On a side note, why mess a round with cheap vintage receivers, you need to feed those bad boys some real he-man power.

Realistically I couldn’t afford anything that I can hear that much difference in. I’ve had separates before and if the damping factor is 30 or 130, in the past I couldn’t hear the diff.

If the distortion is .09 or .003 I couldn’t hear the diff.

The speakers can make all the difference, but to what point! Two week ago I was up at Fred’s Sound of Music in Portland, OR. I sat down in one of their high-end sound rooms.

The amp was gorgeous with outstanding specs, cost $12,000.
The Pre-amp beautiful with exceptional specs, cost $11,500.
The DVD/CD exquisite with dazzling specs, cost $7,000.
The speaker magnificent with superb specs, cost $34,500.
The simple but handsome turntable cost, $4,000 without cartridge.

Good sounding, yes of course but $69,000.00 with out a cartridge to boot….please.

I have an HT system (Polk speaker based) I’m very happy with but I want is a vintage stereo system and if I ever get these SDA working, they’ll will have to be happy with a couple of hundred reasonably clean watts.

I have to like what they look like too. I really hate the looks of: Adcom, Crown, McIntosh, Soundcraftmen and Marantz stuff.

Probably more but these are plain, dull and ordinary to look at. These for me, don’t generate any sizzle or excitement. The McIntosh and the Marantz stuff is really the most unappealing stuff I’ve very seen in electronic equipment, Even the old Dynaco equipment was at least interesting.

BTW what might you consider real he-man power? Maybe the smart looking Superscope model (??) with light pink colored display? (-:

Only joking but I thought the pink was kinda cute.

F1nut

What, no fax??? Everybody has a fax and yes, I have a scanner. The problem there is that the schematic isn't very clear to start with and the last time I sent a scanned copy the party couldn't read it. Tell you what, call Ken at Polk and ask for a hardcopy to be mailed to you.

DO NOT add any extra wiring!!!

I don't know what to say about your hearing, maybe you're blessed or maybe you're cursed.......

He-man power, for SS the likes of Bryston, Plinius, Musical Fidelity, Krell, Parasound JC-1, McCormick, Classe and Bat come to mind. For tubes, Manley, Audio Research, CJ, VAC, Atma-Sphere, BAT and McIntosh. Hybrid, Musical Fidelity.

There are others, but that's all I could think of right now. Oh, by the way none of them come in pink.

marly421

Yes...no faxes out west. The quality is so poor on faxed stuff I normally can't read them anyway.

I surprised about your scanner problems. The resolution is normally so much better and higher with a scanner the fax couldn't possibly compete. I would take a scanned copy over a faxed document any time.

He-man power, for SS the likes of Bryston, Plinius, Musical Fidelity, Krell, Parasound JC-1, McCormick, Classe and Bat come to mind. For tubes, Manley, Audio Research, CJ, VAC, Atma-Sphere, BAT and McIntosh. Hybrid, Musical Fidelity.

Humm your he-man power, I guess I’ve lead a sheltered life. The only one of the group I’ve heard of or seen is the McIntosh. Every time I see a Mac I think of my Grandma’s old wood burning stove…butt ugly (sorry) but functional.

To tell you the truth F1nut I’m tried of messing with these speakers my back aches and my head is throbbing from these things. I’ve already moved my RTA 12A’s back into there place.

Maybe I give Ken a call but probably I’ll just move the SDA's to a corner for a while and in a couple of weeks when I won’t feel the sting of the lost money and time so much I'll move them onto the side-walk for somebody to take or just put them into the dumpster. I guess I get discourage too easily…but after 9 or 10 days I’m just dishearten with the speakers, eBay and the whole messiness of this business.

Thanks F1nut and everybody else who offered help,

Marlene

okiepolkie

Be sure to let everyone know which dumpster it is put in.

[Deleted User]

Hello Marlene,
I'm sorry the speakers are giving you such a fit. I believe probably the first thing to do is to, one-at-a-time, pull each of the 6.5" drivers from the cabinet, on the non-working speaker, disconnect it's wires and try playing it directly powered by your receiver, at a moderate playing volume. You can also do the same thing with the tweeters, removing them and playing them directly powered by the receiver.
The basic test procedure, for an SDA speaker, is to begin playing a monaural source, such as inter-station FM noise. In other words, tune the FM tuner to the area between stations so all you're hearing is the noise between stations. With a monaural source there shouldn't be any sound coming from the SDA sections of either speaker and the sound image should be firmly in the center. If you now rotate the receiver's balance control to the left channel the image should move to the left speaker, all of the tweeters and drivers in the left speaker should be producing sound, but only the SDA drivers/tweeters should be producing sound. Now move the balance to the right and the opposite should happen. The image will move to the right speaker and all of the tweeters/drivers should be working and only the SDA components should be working on the left speaker.
If you don't hear anything coming from the SDA components in the left speaker and the balance is set to the right channel, then try reversing the positive/negative connections on the right speaker. The same if the opposite happens, if the balance is set to the left channel and there's no sound coming from the SDA components of the right speaker reverse the positive/negative connections of the left speaker. If there's no SDA information from either SDA section try reversing the positive/negative connections on both speakers.
With the same monaural source, disconnect both of the negative speaker connections on both speakers and rotate the balance control to the left. You should hear only sound coming from the SDA sections of both speakers. The sound should be very "phasey" sounding, seeming to come from nowhere specific and completely lacking bass. As you rotate the balance control to the center the sound should get less and less and if everything were perfect there wouldn't be any sound when the control is in the middle (called a deep null). Then as you turn the balance the sound should once again appear as before and continue increasing in level until the control is in the right channel. In fact you can "tune" the SDA speakers by setting the balance control to where there is the least amount of sound.
Keep in mind this is with monaural input.
Regards, Ken

Tour2ma

Ken,
Is there a reason you can not post a scanned copy of the SDA Troubleshooting guide either in a thread or in the "Manuals" section?
I thought it was a very useful guide...

[Deleted User]

Hello,
I'll ask Justin, it sounds like a good idea to me.
Ken

marly421

Thanks Ken (Kenneth Swauger),

Before I read your email I did the following. Took the SDA's off the sidewalk and brought them back in, then I put a meter on the problem left speaker & found at least 4 connections that were actually shorts.

I pulled every speaker connection back to & including the x-over's & turned my little Dremel loose with a polishing wheel. I ripped apart the right speaker too.

Now pulling the SDA cable out will not shutdown the rest of the speakers.

I think the phasing of the speakers in the cabinets [Stereo & SDA speakers] are probably wrong. They use white/black & white/blue would a schematic help? I hope I can get these rascals up & working properly again real soon.

Thanks,

Marly

Tour2ma

Glad to read that you are gaining on it...

[Deleted User]

Hello Marley,
I'm glad things are looking more promising for the speakers. If you'll email me your address at kswauger@polkaudio.com I can U.S. Mail you a copy of the crossover schematic and I believe I have a wiring diagram. In general terms white wires are the ground return connection and black wires are the "stereo" positive connection and blue wires are the "SDA" positive connection and the speakers are mirror images of each other. I'm sure we can solve the speaker's problems and getting it sounding proper.
Take care, Ken