SDA 1c lacks wide sound stage - asking for guidance
POLK3429
Posts: 26
I just acquired my second set of SDA speakers - a pair of modified SDA 1c's.
My first set are SDA SRS 2's (blade/blade) - they have a wide sound stage.
I simply swapped the speaker cables from the SDA SRS 2's to the SDA 1c's and was very disappointed with the sound of the 1c's. No wide sound stage and I can tell the sound is coming from the speakers. One test track is Neil Diamond's Soolaimon, and things happen outside both speakers on the SDA SRS 2's, but not on the SDA 1c's.
The seller modified the 1c's a few years ago. They provided the receipts of the various parts:
- Gen I Sonicap capacitors
- Mills resistors
- RD0194 tweeters
- New binding posts
Trouble shooting so far:
- measure continuity of the interconnect cable (both wires) and it checks out
- Test 1 in the SDA handbook - not everything checked out, but I did not record the outcomes of the various tests
- Test 2 - remove the negative connection to each speaker & balance control in the center, and the sound (white noise) did disappear
Does anyone have any tips that I could try prior to disassembling the speakers? Or, is the next step disassembly to validate crossover modifications and driver connections.
My first set are SDA SRS 2's (blade/blade) - they have a wide sound stage.
I simply swapped the speaker cables from the SDA SRS 2's to the SDA 1c's and was very disappointed with the sound of the 1c's. No wide sound stage and I can tell the sound is coming from the speakers. One test track is Neil Diamond's Soolaimon, and things happen outside both speakers on the SDA SRS 2's, but not on the SDA 1c's.
The seller modified the 1c's a few years ago. They provided the receipts of the various parts:
- Gen I Sonicap capacitors
- Mills resistors
- RD0194 tweeters
- New binding posts
Trouble shooting so far:
- measure continuity of the interconnect cable (both wires) and it checks out
- Test 1 in the SDA handbook - not everything checked out, but I did not record the outcomes of the various tests
- Test 2 - remove the negative connection to each speaker & balance control in the center, and the sound (white noise) did disappear
Does anyone have any tips that I could try prior to disassembling the speakers? Or, is the next step disassembly to validate crossover modifications and driver connections.
Comments
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Let me just say this, the SDA 1c will never have as wide a soundstage that the SDA SRS 2 has. The wider driver arrangement on the SDA SRS 2 is directly responsible for the wider soundstage.
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Driver wired incorrectlyPolitical 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 -
Other than a slightly more defined bottom register, they should be very similar in soundstage. Something is amiss with the wiring or crossover build. Maybe shoot us a picture of the setup when you are doing your A/B comparison.
My first set are SDA SRS 2's (blade/blade) - they have a wide sound stage.
Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
Long sigh .......... I just need to suck it up and do the work. Plan will be to:
- remove all of the drivers, and catalog model numbers, locations, connections, etc.
If all that checks out:
- remove the crossovers, trace & draw the circuits, and cross check against the OEM circuit drawing
I was hoping to use the SDA 1c's as my main pair (straight away) while I modified the SDA SRS 2's. Oh well. -
Other than a slightly more defined bottom register, they should be very similar in soundstage. Something is amiss with the wiring or crossover build. Maybe shoot us a picture of the setup when you are doing your A/B comparison.
My first set are SDA SRS 2's (blade/blade) - they have a wide sound stage.
My A/B comparison for the SDA 1c's was to simply place the SDA 1c's in front of the SDA SRS 2's, attach the interconnect cable and move the speaker cables to the 1c's. Thus, the width of the speaker placement was the same as the SRS 2's, but the listening position for the 1c's would have been 12-18 inches shorter. -
I’m far from an SDA expert, but I think that’s an apples and oranges comparison. Aren’t SDAs supposed to be up against a wall? Your positioning might be affecting the bass response enough to collapse the soundstage? Might be worth checking out before tearing into them.
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 -
I’m far from an SDA expert, but I think that’s an apples and oranges comparison. Aren’t SDAs supposed to be up against a wall? Your positioning might be affecting the bass response enough to collapse the soundstage? Might be worth checking out before tearing into them.
The rear of the SDA SRS 2's are normally about 21 inches from the wall behind them, so they are not normally against a wall anyway. However, I moved the SDA SRS 2's farther away from the rear wall, to the position where I had the SDA 1c's, and the SDA SRS 2's still provide a wide sound stage (beyond the speaker's physical location).
Closing my eyes and pointing to the sound source, I point right at the SDA 1c's. That is not the case with the SDA SRS 2's.
I do not expect the SDA 1c's to sound identical to the SDA SRS 2's, but I was expecting a sound stage that extends beyond the physical location of each speaker due to the SDA technology.
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So the ideal positioning of the SDA's is about 6" from the back wall and 6 ft. apart with a listening area about 8ft or more out. When I A/B speakers, I put them in line and right beside one another (so the distance apart is the same for each pair. BUT, I think you're on the right path with troubleshooting the internals. Could be something simple like @F1nut said. Good Luck.Gustard X26 Pro DAC
Belles 21A Pre modded with Mundorf Supreme caps
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
My 1Cs extend about 2-3 ft past the sides for most content, some stuff is more but generally that's what I've heard. Both my untouched pair and rebuilt have the same soundstage size2 channel: MXN10, Anthem MRX740, Anthem MCA5, SDA1c recap/RDO, JL Fathom F112V2, Tributaries series 8A, Tara labs RSC
Theater: Above plus Paradigm reference studio 100, Polk FX300i
Party/1st floor: iPad, Marantz SR5005, Paradigm reference S100v2, monster bulk cable
B&O H9 Gen3 -
The rear of the SDA SRS 2's are normally about 21 inches from the wall behind them, so they are not normally against a wall anyway. However, I moved the SDA SRS 2's farther away from the rear wall, to the position where I had the SDA 1c's, and the SDA SRS 2's still provide a wide sound stage (beyond the speaker's physical location).
5 to 6 inches off the wall is pretty much standard with a 1/2 inch making or breaking it. 21 inches is way too far 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 -
The 1c set I had here was easily throwing 20 ft plus wide stage, great listening session!- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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5 to 6 inches off the wall is pretty much standard with a 1/2 inch making or breaking it. 21 inches is way too far out.
Listened to the SDA SRS 2's at 21" off the wall
* Moved the SDA SRS 2's to 6" off the wall and the sound stage did not sound any different to me - both distances from the wall had a good sound stage and "stuff" was happening outside the speakers
Moved the SDA SRS 2's out and replaced them with the SDA 1c's, 6" off the wall
* I could still pinpoint sound coming from the SDA 1c's
* I flipped the interconnect, just for the heck of it, and no change
* Next phase will be to disassemble
Thanks for the advice so far. -
The reason to place them close to the wall is for the bass response. It has absolutely nothing to do with the soundstage.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 -
So do it already! (just kidding)
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 -
The reason to place them close to the wall is for the bass response. It has absolutely nothing to do with the soundstage.
Kinda/sorta figured, but new to SDA and did it anyway. Got in a mini workout as a bonus with all the moving. The SDA SRS 2's are not lightweight speakers.
The workshop area is 2 floors down so I am going to need a helper to move the SDA 1c's. Hope to move them this weekend. Fingers crossed it is just a polarity issue. -
I had a pair of SDA's come in with a similar situation. Discovered one driver was wired in reverse.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 -
Yeah I think polarity is the answer as well- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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Quick update ......... just started disassembly and there are definitely some wiring issues (plural) at a minimum.
Starting with the right channel 6-1/2" drivers:
1) Top SDA speaker: the (-) wire was NOT even connected
2) The stereo speakers are wired incorrectly. There is a wire that connects the top driver's (+) terminal to the bottom driver's (-) terminal.
I will keep going with a complete disassembly and wiring -
You should glue the magnets while you're at it.
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You should glue the magnets while you're at it.
What is the preferred method? Epoxy? Silicone? Other? -
Original JB Weld two part metal epoxy.
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And some craft sticks (a.k.a. Popsicle sticks.) Have fun. One of the most mind-numbingly dull times of my life, but nice not to have to worry about the potential consequences.
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 -
Stereo array is in series (positive going to negative is correct potentially)
- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit. -
Stereo array is in series (positive going to negative is correct potentially)
Good catch!
The SDA SRS 2 stereo drivers are in parallel ............ but the SDA 1c's stereo drivers are in series. -
Never use RTV silicone in speakers or electronics.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 -
Good catch!
The SDA SRS 2 stereo drivers are in parallel ............ but the SDA 1c's stereo drivers are in series.
Enquiring minds need to know.....was it a black wire with a white tape wrap on the other end or a white wire with black tape 🤣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 -
Nice find….
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So some of you guys are still around? Howdy! Been a while since I was on the forum. My SDA-1Cs benefited mightily from your advice. And you guys who are brave enough to tackle the wiring harness on the SDA Polks, anyone interested in replacing mine with 21st Century wire?Polk SDA-1Cs with RD0194-1 upgrade tweeters, SoniCaps, Clarity PX, Gimpod boards, Cardas BPs, Erse inductors, Canare 4S11 IC; Michi P5; Yamaha M-80; Yamaha CD-S1000; Oppo BDP-95; Sony UBP-X800M2; EverSolo DMP-A6; Topping DX-7 Pro +; Technics SL-1400 with Ortofon 2M Bronze PnP; Vincent Pho 701; PS Audio Dectet; AudioQuest Red River ICs; AudioQuest NRG-Z3 PCs; RapcoHorizon High Def High 413-Strand 10AWG Speaker Cable; Auralex Isolation Pads
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Well, it took a minute, but I was able to go through all the driver connections this weekend. I found 2 issues, both with the upper SDA drivers:
1) Right channel: the (-) wire was NOT connected to the upper SDA driver. Thus, I connected it.
2) Left channel: the upper SDA driver was wired with the opposite polarity of the bottom SDA driver. The bottom SDA driver looked correct according to the wiring diagram (see above), but the upper SDA driver was connected with the opposite polarity. I swapped connections on the upper SDA driver to match the bottom SDA driver.
I played some SDA test tracks after making the above mentioned connections:
a) I can hear some "stuff" outside the physical enclosure for the left channel
b) Right channel still does not exhibit the SDA effect - close your eyes and I still point to the physical cabinet for the origination of all sounds.
My SDA SRS 2's still sound as expected with the same source material.
Any ideas for next step troubleshooting for these SDA 1c's?
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I would start tracing the components on the crossover since the previous owner doesn't seem to know what they were doing.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
