Problem with SDA 1B's
Hi everyone.
This is a great Forum. I have enjoyed reading many of the older threads.
I am having a problem with my pair of SDA 1B's and turn to you for help. The problem is with the left speaker. It is just not as loud as the right speaker. It sounds underpowered. The music from the speakers is still great but I know something is amiss.
I purchased these speakers in Houston, Texas in 1987. The store had a promotion in 1986 and would allow you trade in any speakers purchased within one year for a full price discount on a higher priced item. I originally bought a set of Monitor 10B's which I thought were fabulous (and without stands). However, the SDA 1's always had my attention (and ear) so I did the trade-in nearly a year later. The receipt says the speakers are natural walnut SDA 1A's but I believe them to be 1B's based on the configuration of the tweeters and woofers with the screens removed. They are still beautiful and I still have the original boxes. Attached below is a picture of the right speaker.
The speakers are powered by a Yamaha A-520 integrated amplifier rated at 75 Watts per channel purchased in 1986 with the Polk Monitor 10's. My CD player is a Denon 1300.
I followed the SDA test by TennMan, posted November 2019, to wit:
"Here a few basic tests that I do to my SDAs to ensure they are in phase and the SDA is working. Use a music CD for the tests below - not the audio setup CD.
Test 1) Disconnect all the cables from the speaker. Then momentarily connect a 1.5 volt battery across the + and - terminals of the left speaker observing proper polarity. All the mid-woofers should move outward when the battery is connected. Repeat the test for the right speaker.
Test 2) With the interconnect cable disconnected, play some music at moderate levels. Then turn the balance knob all the way to the left. You should hear music coming from the left speaker and NO sound from the right speaker. Next, turn the balance knob all the way to the right. You should hear music coming from the right speaker and NO sound from the left speaker.
Test 3) With the interconnect cable connected, play some music at moderate levels. Then turn the balance knob all the way to the left. You should hear music coming from the left speaker and you should also hear music coming from only the dimensional speakers of the RIGHT speaker at a lower level. Next, turn the balance knob all the way to the right. You should hear music coming from the right speaker and you should also hear music coming from only the dimensional speakers of the LEFT speaker at a lower level.
If your speakers pass all these tests, check your speaker wire connections at the speakers and the amplifier to make sure the polarity is correct. And as pitdogg2 said, make sure the nuts on the binding terminals haven't been swapped,
You should also remove the tweeters and visually inspect them to make sure they are connected properly to ensure they are in proper phase
"Joshua" just kept reinterrating that I would not be getting the Full SDA effect without the interconnect cable connected. He is correct. Without the cable connected you will only get normal stereo sound which defeats the purpose of owning a pair of SDA speakers. "
My results:
Test 1: My speakers performed perfectly with the battery test for Test 1.
Test 2: This was the problem. With the interconnect cable disconnected, only the right speaker would play. When I turned the balance knob all the way to the left for the left speaker - no sound. When I turned the balance knob all the way to the right - only the right speaker played.
Test 3: I believe my speakers passed this test with the interconnect cable connected. I could hear music from both speakers when the balance knob was turned all the way to the right and then all the way to the left. If the dimensional speakers are the two speakers on the left facing the left speaker and on the right when facing the right speaker, what I call the 2 outside speakers, then I believe my speakers passed this test.
All help and responses would be greatly appreciated. Do I have a speaker problem? Or maybe an amplifier problem? I am living in Northern Kentucky, just south of Cincinnati. Any recommendations for a good repair shop, if needed, would also be appreciated.
TD_
This is a great Forum. I have enjoyed reading many of the older threads.
I am having a problem with my pair of SDA 1B's and turn to you for help. The problem is with the left speaker. It is just not as loud as the right speaker. It sounds underpowered. The music from the speakers is still great but I know something is amiss.
I purchased these speakers in Houston, Texas in 1987. The store had a promotion in 1986 and would allow you trade in any speakers purchased within one year for a full price discount on a higher priced item. I originally bought a set of Monitor 10B's which I thought were fabulous (and without stands). However, the SDA 1's always had my attention (and ear) so I did the trade-in nearly a year later. The receipt says the speakers are natural walnut SDA 1A's but I believe them to be 1B's based on the configuration of the tweeters and woofers with the screens removed. They are still beautiful and I still have the original boxes. Attached below is a picture of the right speaker.
The speakers are powered by a Yamaha A-520 integrated amplifier rated at 75 Watts per channel purchased in 1986 with the Polk Monitor 10's. My CD player is a Denon 1300.
I followed the SDA test by TennMan, posted November 2019, to wit:
"Here a few basic tests that I do to my SDAs to ensure they are in phase and the SDA is working. Use a music CD for the tests below - not the audio setup CD.
Test 1) Disconnect all the cables from the speaker. Then momentarily connect a 1.5 volt battery across the + and - terminals of the left speaker observing proper polarity. All the mid-woofers should move outward when the battery is connected. Repeat the test for the right speaker.
Test 2) With the interconnect cable disconnected, play some music at moderate levels. Then turn the balance knob all the way to the left. You should hear music coming from the left speaker and NO sound from the right speaker. Next, turn the balance knob all the way to the right. You should hear music coming from the right speaker and NO sound from the left speaker.
Test 3) With the interconnect cable connected, play some music at moderate levels. Then turn the balance knob all the way to the left. You should hear music coming from the left speaker and you should also hear music coming from only the dimensional speakers of the RIGHT speaker at a lower level. Next, turn the balance knob all the way to the right. You should hear music coming from the right speaker and you should also hear music coming from only the dimensional speakers of the LEFT speaker at a lower level.
If your speakers pass all these tests, check your speaker wire connections at the speakers and the amplifier to make sure the polarity is correct. And as pitdogg2 said, make sure the nuts on the binding terminals haven't been swapped,
You should also remove the tweeters and visually inspect them to make sure they are connected properly to ensure they are in proper phase
"Joshua" just kept reinterrating that I would not be getting the Full SDA effect without the interconnect cable connected. He is correct. Without the cable connected you will only get normal stereo sound which defeats the purpose of owning a pair of SDA speakers. "
My results:
Test 1: My speakers performed perfectly with the battery test for Test 1.
Test 2: This was the problem. With the interconnect cable disconnected, only the right speaker would play. When I turned the balance knob all the way to the left for the left speaker - no sound. When I turned the balance knob all the way to the right - only the right speaker played.
Test 3: I believe my speakers passed this test with the interconnect cable connected. I could hear music from both speakers when the balance knob was turned all the way to the right and then all the way to the left. If the dimensional speakers are the two speakers on the left facing the left speaker and on the right when facing the right speaker, what I call the 2 outside speakers, then I believe my speakers passed this test.
All help and responses would be greatly appreciated. Do I have a speaker problem? Or maybe an amplifier problem? I am living in Northern Kentucky, just south of Cincinnati. Any recommendations for a good repair shop, if needed, would also be appreciated.
TD_
Comments
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Are there any fuses or polyswitches on these speakers? They should be checked.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
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 -
Polyswitch will not affect the woofers and IIRC they dropped fuses with the SDA 1a
Time to check woofers for magnet slippage. Gently put your fingers around the dust cap gently push straight in trying not to push more on one side or the other. If you can push all the way down to a stop gently and release with your fingers always on the speaker cone around the dust cap push in and follow in and out and feel for a scraping feeling. If it doesn't want to push in don't Force it the magnet has slipped and pinched The voice coil. if you feel the scratchiness and it still pushes in and comes out and you feel the scratchiness all the way in and out still you have a magnet that has slipped and has yet to completely pinched the voice coil.
Those mw6509's are very rare. -
I appreciate the responses.
I am not sure I feel comfortable pushing on the woofers. I have read spare parts are difficult to find for the SDA's so I don't want to inadvertently break something that is not broken. Is there any other way to tell if the magnets have slipped.
Is the banana plug where the two wires from the speakers connect into the amplifier? -
If you hold a 9V battery to the midbass momentarily you should get a fair amount of displacement of the cone.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
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 -
Have you another pair of speakers to connect to your amp/speaker cables to see if you get both channels operating, taking the SDAs out of the equation?
Have you tried reversing your speaker cables to see if the left speaker remains silent, or whether the problem switches sides, L to R?
It would be good to determine if the problem is in the last link of the chain (your speakers) or if it's something earlier such as amp or speaker cables/connections.
Good luck!Jay
SDA 2BTL * Musical Fidelity A5cr amp * Oppo BDP-93 * Modded Adcom GDA-600 DAC * Rythmik F8 (x2)
Micro Seiki DQ-50 * Hagerman Cornet 2 Phono * A hodgepodge of cabling * Belkin PF60
Preamp rotation: Krell KSL (SCompRacer recapped) * Manley Shrimp * PS Audio 5.0 -
This is a great forum. I knew I had a great set of speakers when I made the purchase in 1987. I figured these would be my last set of speakers and so far, that is how it has worked out. That is one reason I opted for the more expensive natural walnut exterior. I always thought I would upgrade my amplifier but never really found the need.
butterbean got me to thinking and working on the problem with the equipment at hand. No, agfrost, I do not have another set of speakers but with your and butterbean's comments, I decided to start swapping things out, Upon moving the problem left speaker to the right side (with the interconnect cable disconnected) I learned that the speaker functioned perfectly in stereo mode. I also moved the right speaker to the left side and encountered the same problem. I thought I had the problem narrowed down to my amplifier but when I swapped around the cables, both speakers worked as they were supposed to (but on opposite or the wrong sides of the room) Moving the speakers back to the proper position, everything worked great. Hooking up the interconnect cable and my SDA sound was back!
I have never liked how the speaker cables connect to the back of the Yamaha A-520 amplifier. It appears that I did not have a good connection on the left side. Moving everything around I must have made the proper connection and the magic returned.
Of course, something still could be wrong as this is very old equipment. I will give it another test later today. Flim and the BB's Tricyle CD sure sounded good. Then on to some Supertramp! Pink Floyd today...
Any ideas on what to do with or how to modify the factory Yamaha cable connectors would be appreciated.
If any problems arise, I will be back with an update. In the meantime, I enjoyed spending time reading the old POLK literature and I had saved all these years. I may have a few questions in the Vintage Speaker forum.
Again, this is a great place on the Internet. -
From what I can see the binding posts on your Yamaha accept banana plugs, spades and bare wire. What type of termination do your speaker cables have?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,
Thank you for your reply.
My speaker cables have bare wire on both ends. The speaker cable ends drop in a hole on the back of the Polk speakers and the red and black plastic knobs tighten against the wire.
The amplifier has red and black knobs that partially unscrew and allow the bare cable wire to be inserted in a small slot. The knobs are then tightened to make the connection.
The Yamaha A-520 manual states:
"Loosen the speaker terminal knobs, insert the speaker cord and then tighten up the speaker terminal knobs." -
F1nut,
Thank you for your reply.
My speaker cables have bare wire on both ends. The speaker cable ends drop in a hole on the back of the Polk speakers and the red and black plastic knobs tighten against the wire.
The amplifier has red and black knobs that partially unscrew and allow the bare cable wire to be inserted in a small slot. The knobs are then tightened to make the connection.
The Yamaha A-520 manual states:
"Loosen the speaker terminal knobs, insert the speaker cord and then tighten up the speaker terminal knobs."
Banana plugs, even spades are a better option than bare wire. Banana plug designs vary wildly and most these days use screws to clamp the wire. I prefer the type that allows a solder connection and have large solid shaft through the middle ending in a dome. This is an example, https://www.thecableco.com/reference-banana-set-of-2.htmlPolitical 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 -
What’s wrong with bare wire , besides the convenience factor ?
I would think bare wire would actually provide the greatest contact surface area .
BkPS Audio S300 , WiiM Ultra , Yamaha wxc-50 , Salk SuperCharged Songtowers , Kimber Kable 4TC, Sony 48” - BEDROOM
B&K EX-442 ( it will go in my casket when I die ... ) , PS Audio 4.6 preamp ( old school , but it still jams on ... ) , Eversolo DMP-A6 , Boston Acoustic voyager 7’s - POOL
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Onkyo TX-nr609 , Polk atrium 7 , Boston acoustic sound ware (4) , Boston acoustic sub , B&W center , Sony 65” TV - PATIO -
butterbean and F1nut,
Thank you for your replies. If I understand completely, the banana plug on the end of the speaker wire would drop in the vertical hole on the speaker post on the Polk speaker and allow the red and black plastic knobs to tighten down on the plug. Same with the amplifier: the banana plug would drop in the slot and allow the plastic knobs to tighten down on the plug, thereby creating a solid connection.
And I always thought banana plugs were only for plug-in applications! -
Copper oxidation issues and definitely not the largest contact.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 -
butterbean and F1nut,
Thank you for your replies. If I understand completely, the banana plug on the end of the speaker wire would drop in the vertical hole on the speaker post on the Polk speaker and allow the red and black plastic knobs to tighten down on the plug. Same with the amplifier: the banana plug would drop in the slot and allow the plastic knobs to tighten down on the plug, thereby creating a solid connection.
And I always thought banana plugs were only for plug-in applications! -
The plastic knobs don't come into play at all when using banana plugs. You would want to screw them all the way down though probably. I don't use them.George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
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 -
butterbean and F1nut,
Thank you for your replies. If I understand completely, the banana plug on the end of the speaker wire would drop in the vertical hole on the speaker post on the Polk speaker and allow the red and black plastic knobs to tighten down on the plug. Same with the amplifier: the banana plug would drop in the slot and allow the plastic knobs to tighten down on the plug, thereby creating a solid connection.
And I always thought banana plugs were only for plug-in applications!
Oh hell no! The banana plug is inserted into the hole that would be staring you in the face.
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 -
This is way off base, The banana plugs will plug into your speaker's binding post as shown below. Banana plugs should insert into your amp's binding post the same way. Ignore my interconnect cable connection. It has been upgraded and will be different from yours.butterbean and F1nut,
Thank you for your replies. If I understand completely, the banana plug on the end of the speaker wire would drop in the vertical hole on the speaker post on the Polk speaker and allow the red and black plastic knobs to tighten down on the plug. Same with the amplifier: the banana plug would drop in the slot and allow the plastic knobs to tighten down on the plug, thereby creating a solid connection.
And I always thought banana plugs were only for plug-in applications!
I'm happy to hear the testing instructions helped you find your problem.
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You owe me a new monitor cause I just blew my drink all over mine .. -
ken brydson wrote: »
You owe me a new monitor cause I just blew my drink all over mine ..
you still got that kind of range at your age ?... OH WAIT..... you said drink.... nevermind move along nothing to see here.... -
I apologize for the duplicate posts. I am on another computer today so that may have an impact on my ability to post. Maybe a moderator can delete those posts.
butterbean and F1nut,
Thank you for the information on the banana plugs. Thanks to the picture by TennMan, I can tell banana clips would certainly work in my SDA speakers. I am still not sure about the knobs on the A-520 Yamaha amplifier. I am attaching a picture of the speaker connector terminals on my A-520 along with an excerpt from the manual.
I noted the knobs do not have a metal center as the example picture posted by F1nut. That said, do you think these speaker connector terminals will accept a banana plug?
I am using 16 gauge Monster Cable.
TennMan,
Your instructions for testing SDA speakers was great!
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For some stupid reason some Japanese manufacturers such as Sony installed binding posts with holes that looked like they would accept banana plugs, but don't. Yours might be one of those. You could buy a cheap banana plug to test with.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 -
For some stupid reason some Japanese manufacturers such as Sony installed binding posts with holes that looked like they would accept banana plugs, but don't. Yours might be one of those. You could buy a cheap banana plug to test with.
So did Onkyo! My Integra M504 wont except a standard banana plug.
--Gary--
Onkyo Integra M504, Bottlehead Foreplay III, Denon SACD, Thiel CS2.3, NHT VT-2, VT-3 and Evolution T6, Infinity RSIIIa, SDA1C and a few dozen other speakers around the house I change in and out. -
F1nut,
"For some stupid reason some Japanese....." You are correct, sir. Regarding the "cheap banana plugs," our Best Buy store had an open box special on 4 banana plugs that was impossible to resist. The plugs did not work on the amplifier but worked great on the Polk SDAs. I researched the promotional literature I saved for the A-520 and found the terminal connectors were actually a feature, not some stupid Japanese...
For your reading pleasure:
All that said, I cannot complain about a $329 amplifier that was rated at 75 Watts Per Channel - and has lasted nearly 34 years. I really wanted the A-720 at 100 Watts Per Channel but it cost $469! Further review of some other period literature I saved showed the higher end Yamaha AX amplifier series terminal connectors would accept banana plugs - but they started at over $500
I am very thankful for everyone's comments and suggestions. My system is running great and the speakers sound as magnificent as the day they were delivered. This is a great place to be if you love Polk speakers. The SDA 1B's are simply fantastic. I have a friend, still in Houston, who purchased a pair of Vandersteen's during the same time frame with NAD electronics. I enjoy listening to his Vandersteen's when we visit but I still prefer Mathew Polk's speakers. -
I researched the promotional literature I saved for the A-520 and found the terminal connectors were actually a feature, not some stupid Japanese...
That's not a feature, it's a disservice and it's stupid. The Japanese were the only ones doing that back in the '80/90's. Look at current Japanese gear, even their cheap consumer grade gear allows for the use of banana plugs.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 -
I researched the promotional literature I saved for the A-520 and found the terminal connectors were actually a feature, not some stupid Japanese...
That's not a feature, it's a disservice and it's stupid. The Japanese were the only ones doing that back in the '80/90's. Look at current Japanese gear, even their cheap consumer grade gear allows for the use of banana plugs.
Hey Jesse, we have a thread just for you...”Feel the Hate” just let it out, tell us how you feel
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erat interfectorem cesar et **** dictatorem dicere a -
I'd get banned in a heartbeat if I just let it out.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
