SDA-2 (originals) wiring help! Please
Gavin.Wright
Posts: 125
Hi,
I recently picked up a pair of SDA-2's and am not sure they are wired correctly. This morning I checked the bass output of each with a tone generator and noticed that my right speaker had noticeably higher bass output. I have a schematic for these speakers but it does not give any wire colors to help troubleshoot. I swapped the connections on the left dimensional woofer and I seem to have more bass (equal to that of the right channel) since doing so. I think I might be noticing some of the "SDA" effects now as well but i'm just not sure. Can anyone help me out with wiring? The wire colors for my dimensional woofers are white and blue while the main drivers I believe are white and black. Please! :biggrin:
I recently picked up a pair of SDA-2's and am not sure they are wired correctly. This morning I checked the bass output of each with a tone generator and noticed that my right speaker had noticeably higher bass output. I have a schematic for these speakers but it does not give any wire colors to help troubleshoot. I swapped the connections on the left dimensional woofer and I seem to have more bass (equal to that of the right channel) since doing so. I think I might be noticing some of the "SDA" effects now as well but i'm just not sure. Can anyone help me out with wiring? The wire colors for my dimensional woofers are white and blue while the main drivers I believe are white and black. Please! :biggrin:
Post edited by Gavin.Wright on
Comments
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Black or blue are positive. White or green are negative.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
F1nut - if that's the case then why would I be getting more bass from the left channel when I wire the dimensional woofer positive/white and negative/blue?
I'm at a loss here -
Check the wires at the binding post on that speaker and/or amp, make sure you've got them wired in phase. neg to neg, pos to pos“The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
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Everything is in phase from the amp to the binding posts and the IC is hooked up correctly. I just can't figure out why the right channel would have so much bass and the right has so little until I reverse the dimensional woofer's connections... I feel like I actually experience the SDA effect when the left speaker dimensional woofer is reversed... sigh
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I had a similar problem with my 1C's years ago-- and it was in the wiring--I had them reversed--the dimensional vs the stereo.Good luck,keep us posted.JC approves....he told me so. (F-1 nut)
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Are you using the original IC or did you make one up. If you made one up I think (don't hold me to it, don't have one to check) there suppose to be a strait through connection, big blade to big blade, little to little“The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
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hmmm,, blade/blade---good call Gimpod.JC approves....he told me so. (F-1 nut)
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I made one - but it is straight through -
wouldn't the IC damage my amp if it were wired incorrectly? -
Troubleshooting guide, http://www.polkaudio.com/forums/showpost.php?p=1297248&postcount=9Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
If your wiring checks out and there is no obivious leak in the pr,,it's gotta be the IC(blade/blade)JC approves....he told me so. (F-1 nut)
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thanks F1nut - I have gone through the guide already which is what led me to believe that my left channel dimensional woofer was incorrectly wired... I just can't figure out why the color codes don't match up and would like to make sure I get everything properly setup.
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Are you sure your amp is common ground, Try disconnecting the IC after you've got the speaker wired back to the way it's suppose to be just to see if the bass evens out.“The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
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the amp is definitely common ground - verified through a DVM and schematic, both speakers sound fine without the IC connected - both have equal bass output without the IC connected. When I connect the IC the right channel gains a small amount of bass and the left channel loses a good deal of bass (unless I reverse the connections on the left channel's dimensional woofer)
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Than it has to be your IC cable. We need someone to verify if this cable is wired strait through or not. You might have to call Polk CS on Monday to find out.“The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
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looking at the schematic for the SDA-2 it looks like if I reverse the connections on the IC it will directly connect the positive Left and Right sides of my amplifier together which I would prefer to avoid :biggrin: oh dear.
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I may be wrong,, but I thought I remembered reading somewhere that the B/B wiring at the ends was reversed,, I still think it's your IC.Good luck--keep us posted,, I won't begin to tell you the things I've done with SDA's as part of my learning process,,such as reversing the speaker cables when using a tubed pre that inverts phase,,but I never blew anything up.Good luck.JC approves....he told me so. (F-1 nut)
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JC approves....he told me so. (F-1 nut)
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Gavin.Wright wrote: »looking at the schematic for the SDA-2 it looks like if I reverse the connections on the IC it will directly connect the positive Left and Right sides of my amplifier together which I would prefer to avoid :biggrin: oh dear.
It looks that way to me too. I might suggest that you recheck the connectors on your IC and make sure you don't have a connection between the small and large blade. A stray wire, solder bridge etc.. or that you inadvertently crossed the wires without noticing stranger things have happened Hope this helps“The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain -
that's for all the help - i have reconfirmed my IC connections and I really think that the left channel dimensional woofer is just incorrectly wired. When i reverse the connections i'm getting very 3-dimensional sound - just finished listening to brothers in arms and I swear the strings were directly to my left and right - i had to check and make sure I was running in stereo mode and not surround. The other track I tried was aqua lung's "if i fall" from their strange and beautiful album - the intro notes seem to come from directly to my left - when I reverse the dimensional speaker this intro sounds muted and comes from the right side speaker. this is all so confusing!
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the bass is good - if i pan left/right it is equal on both sides and additive when both channels are run. if i reverse the connections to the left side dimensional woofer the bass becomes flimsy out of that speaker but only with the IC cable connected (which makes sense if the dimensional woofer were to have been wired out of phase with the rest of that left side speaker). Thoughts?
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Boy you got me. The only other thing I can think of is to see if that driver is wired the same at the crossover for both speakers.
I think they may have been smoking a little herb back then. :rolleyes:
“The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain -
Okay - so get this.
I removed the dimensional woofers from both speakers and hooked them directly up to a separate amp and sent them a low frequency signal. I first tested them both hooked up correctly - positive to positive, negative to negative. This gave very limited bass output. I then reversed the connection of one speaker and the bass returned! I then grabbed a couple of "known to be good" yamaha 6.5" woofers and used them to figure out which polk woofer was internally wired backwards. I was able to determine which woofer was backwards but I just don't understand how this could happen... perhaps the terminals are simply mislabeled on this speaker? What gives speakers "phase" anyhow...
anyone? -
Is the "bad" driver one of the ones you had to fix if so it could have a damaged voice coil. You might try and take your DVM and check to see if there is continuity between the basket and terminal. This is one reason why fixing a frozen driver has such a high failure rate. Also check the Ohm reading between the two drivers they should be the same. I would start looking for some replacement drivers.“The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
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I think this is one that was repaired. I just checked the DC resistance and it reads right around 7.6ohms - same as the other speakers in the cab. I do not have any continuity between the basket and either the positive or negative terminals. The speaker seems to play fine.
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Wow,, this kind of issue really taxes the troubleshooting process-- good on you--I hope these sound fantastic,,Lord knows you've earned it.
JC approves....he told me so. (F-1 nut) -
I was able to determine which woofer was backwards but I just don't understand how this could happen...
And here's your answer....Is the "bad" driver one of the ones you had to fixPolitical Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
F1nut - any idea how repairing one of these speakers could cause the phase to reverse? It seems odd that the speaker is fully functional other than the reversed phase...
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Phase refers to the timing relationship of two or more signals or sound waves. You always want to insure that your stereo speakers [and all associated drivers within] are playing "in phase." This means that the drivers of your right and left speakers are all moving in and out at the same time and not opposite of each other, which is the way you had it hooked up.Gavin.Wright wrote: »What gives speakers "phase" anyhow...
If your stereo speakers are out of phase [that is, with one set of positive and negative leads reversed] you'll hear significantly less bass, and instead of producing a strong center image, the sound tends to stay localized at the speakers. So long as everything is now in phase, you are good to go.~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~ -
Gavin.Wright wrote: »F1nut - any idea how repairing one of these speakers could cause the phase to reverse? It seems odd that the speaker is fully functional other than the reversed phase...
Nope, but obviously something happened.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk
