SDA1b (or early c) - opinions?

JayMX
JayMX Posts: 434
edited October 2018 in Vintage Speakers
Picking these up tomorrow for a song. No interconnect, but can build one. Opinions? Suggestions? Thoughts? Where do these fall on the ol Polk desirability scale?
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Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
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Comments

  • JayMX
    JayMX Posts: 434
    What are the differences between the 1B’s & early 1C’s other than driver loading?
    u3pcd5knzkc6.jpeg
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • mlistens03
    mlistens03 Posts: 2,767
    Looks like the SDA 1C uses the MW6511 for stereo drivers and 6510 for dimensional, 1B seems to use MW6509 for both. I’d guess one is easier to driver, or something.
    Value wise? No clue.
  • westmassguy
    westmassguy Posts: 6,850
    Completely different generations. The 1B is 3rd, 1C is 4th. 1C is more desirable, and relatively easier to drive. 1B is 4 ohm, 1C 6 ohm nominal.
    Some early 1Cs used leftover circuit boards from the 1Bs.
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer

    dhsspeakerservice.com/
  • mlistens03
    mlistens03 Posts: 2,767
    JayMX wrote: »
    What are the differences between the 1B’s & early 1C’s other than driver loading?

    🤦🏻‍♂️Missed that, sorry.
  • JayMX
    JayMX Posts: 434
    edited October 2018
    Completely different generations. The 1B is 3rd, 1C is 4th. 1C is more desirable,....

    Some early 1Cs used leftover circuit boards from the 1Bs.

    So they may be C’s even if they are blade/blade... if are loaded with 6510’s & 11’s they should be usable with isolation transformer/mono blocks? Correct?
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • Dennis Gardner
    Dennis Gardner Posts: 4,860
    edited October 2018
    Those serial numbers indicate that they can't be used with monoblocks.

    https://us.v-cdn.net/5021930/uploads/attachments/6/4/8/2/8/9806.jpg
    HT Optoma HD25 LV on 80" DIY Screen, Anthem MRX 300 Receiver, Pioneer Elite BDP 51FD Polk CS350LS, Polk SDA1C, Polk FX300, Polk RT55, Dual EBS Adire Shiva 320watt tuned to 17hz, ICs-DIY Twisted Prs, Speaker-Raymond Cable

    2 Channel Thorens TD 318 Grado ZF1, SACD/CD Marantz 8260, Soundstream/Krell DAC1, Audio Mirror PP1, Odyssey Stratos, ADS L-1290, ICs-DIY Twisted , Speaker-Raymond Cable
  • Malbec
    Malbec Posts: 548
    These don't appear to be compatible with the isolation transformer.

    NOTE: Some early units of SDA-1C and all units of SDA-2B require plug adapters and some internal modifications to the crossover to be used with the Non-Common Ground Amplifier Interface. The affected SDA-1C units can be identified by serial number as follows:
    Right Channel #6001 through 6310 and #6501 through 6678 Left Channel #5975 through 6370 and #6532 through 6656

    If the serial numbers of your speakers fall within these limits, please contact Polk Audio for modification details.
  • JayMX
    JayMX Posts: 434
    perfect. This helps me with determining what to offer the guy selling. The cabinets look rough, hoping to get them for less than a Benjamin! We will see what this afternoon holds. Thanks all.
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • JayMX
    JayMX Posts: 434
    @la2vegas - if I actually sang, he would prob kick me out. He mentioned a hundo, ima see if I can talk him down a bit. Wish me luck!
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • JayMX
    JayMX Posts: 434
    edited October 2018
    Definitely B’s loaded with 6509’s. Pretty thrashed. Two bad tweets, three locked up mids. Cracked cabinet. Rough vinyl veneer. And free cobwebs! All for $80!! I will bring them back from the brink of death though. This I swear. 🤘🏻
    axefbqqspxsd.jpeg
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    bgy2hhl94fc9.jpeg


    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • xschop
    xschop Posts: 4,636
    Halloween specials right there. Can't wait to see the resto-mod.
    Don't take experimental gene therapies from known eugenicists.
  • verb
    verb Posts: 10,176
    Nice find @JayMX ! Nothing that can’t be fixed! Just needs some love. Be sure to document your journey!
    Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
    Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
    Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
    Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
    Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
    Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD.
  • The very first SDA’s I ever owned were a pair of 1b’s that looked just like these. They forced me to buy a new Receiver as the impedance dips pretty low on these. I had a Realistic receiver (remember THOSE???) when I got these and it would play just fine until I turned up the volume. Then you would hear a loud *clack* come from the receiver and the sound would cut out (meaning the protection circuit would disconnect the amp from the signal path) Once I turned the volume down the sound would come back. I replaced it with an NAD receiver and was very happy (at least until a friend who liked to brag about his Luxman receiver accepted my challenge to bring it over and I discovered it sounded way better than my NAD! :s )
  • Schurkey
    Schurkey Posts: 2,100
    edited October 2018
    Those serial numbers indicate that they can't be used with monoblocks.

    https://us.v-cdn.net/5021930/uploads/attachments/6/4/8/2/8/9806.jpg
    Malbec wrote: »
    These don't appear to be compatible with the isolation transformer.

    NOTE: Some early units of SDA-1C and all units of SDA-2B require plug adapters and some internal modifications to the crossover to be used with the Non-Common Ground Amplifier Interface. The affected SDA-1C units can be identified by serial number as follows:
    Right Channel #6001 through 6310 and #6501 through 6678 Left Channel #5975 through 6370 and #6532 through 6656

    If the serial numbers of your speakers fall within these limits, please contact Polk Audio for modification details.
    The early 1Cs are ABSOLUTELY compatible with an isolation transformer IF you are willing to add ~eight inches of wire and change the socket that the interconnect cable attaches to.

    In fact, if you're making your own interconnect cable to go with your Dreadnought, you just tie the ground side of the transformer to the negative binding post and you don't need the eight inches of wire inside the cabinet.

    Seems the "hot tip" is to remove the OEM socket for the interconnect cable, and replace it with a Speakon-style connector, so again you'd need a little wire added inside the cabinet.

    Many ways to skin this cat--IF these are early 1Cs. If they're 1Bs, you're pretty well screwed in terms of an isolation transformer.

    http://forum.polkaudio.com/discussion/131691/2b-and-early-1c-ai-1-modifications#latest

    Given the very-low serial numbers, I expect these are 1Bs, but a look at the midwoofer model numbers will confirm.

    I've had 1Bs since about 1986, bought them as "store demo" when the 1B was being replaced with the 1C. They're terrific-sounding speakers, even moreso when the crossovers are gone through, and you pull all the Dacron back up where it belongs, add the updated tweeters, etc.

  • F1nut
    F1nut Posts: 49,704
    Ummmm......."Definitely B’s loaded with 6509’s."
    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

  • Schurkey
    Schurkey Posts: 2,100
    F1nut wrote: »
    Ummmm......."Definitely B’s loaded with 6509’s."
    Mia Culpa.
  • JayMX
    JayMX Posts: 434
    So I’ve finally got these to a point where they’re somewhat decent to look at. And they work for the most part. I went through all eight of the MW6509's, six of which were locked up. I aligned and glued all of them. When I finally reassembled I found that I didn’t do a good job on one of them. How hard is it to break the bond on loctite red and powergrab?
    7g00ent3lwpa.jpeg
    r33hjs30jyrc.jpeg
    ydq1iqskr31f.jpeg
    jslxf2rhwe91.jpeg
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • FestYboy
    FestYboy Posts: 3,861
    The power grab will be the worst of it. Just break loose the pole plate and align from there with your PVC rig.
  • audioluvr
    audioluvr Posts: 5,420
    Nice job! They look great!
    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
  • Schurkey
    Schurkey Posts: 2,100
    JayMX wrote: »
    So I’ve finally got these to a point where they’re somewhat decent to look at.
    No shiit! They're beautiful!
    JayMX wrote: »
    And they work for the most part. I went through all eight of the MW6509's, six of which were locked up. I aligned and glued all of them. When I finally reassembled I found that I didn’t do a good job on one of them. How hard is it to break the bond on loctite red and powergrab?
    You won't have any fun breaking them apart again. I don't expect the powergrab to be a big deal, but the anaerobic Loctite will be...interesting. Theoretically, you'd need heat to soften the adhesive, but doing that puts the rest of the driver in danger. I would heat only the pole piece and see what happens.

    Leave the magnet attached to the basket. Then clean up the pole piece and the facing part of the magnet. Center the pole piece in the voice coil, instead of trying to center the pole piece AND the magnet.

  • monepolk
    monepolk Posts: 1,140
    Great job! They look fantastic.
  • txcoastal1
    txcoastal1 Posts: 13,124
    Like breathing life into Frankenstein
    Great work
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • JayMX
    JayMX Posts: 434
    I forgot I had this photo. This little one was building the webs...
    5z5drp8qv8sg.jpeg
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (3x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • audioluvr
    audioluvr Posts: 5,420
    AAAa cute! Momma must be near by though... :#:#
    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
  • verb
    verb Posts: 10,176
    Fabulous job! Especially considering the condition when you started! Looking good! :smile:
    Basement: Polk SDA SRS 1.2tl's, Cary SLP-05 Pre with ultimate upgrade,McIntosh MCD301 CD/SACD player, Northstar Designs Excelsio DAC, Cambridge 851N streamer, McIntosh MC300 Amp, Silnote Morpheus Ref2, Series2 Digital Cables, Silnote Morpheus Ref2 Series2 XLR's, Furman 15PFi Power Conditioner, Pangea Power Cables, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
    Office: PC, EAR Acute CD Player, EAR 834L Pre, Northstar Designs Intenso DAC, Antique Sound Labs AV8 Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
    Spare Room: Dayens Ampino Integrated Amp, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's, Shunyata Hydra 8 Power Conditioner
    Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Rotel RCD-1072 CD player, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
    Garage #1: Cambridge Audio 640A Integrated Amp, Project Box-E BT Streamer, Polk Tsi200 Bookies, Douglas Speaker Cables, Shunyata Power Conditioner
    Garage #2: Cambridge Audio EVO150 Integrated Amplifier, Polk L200's, Analysis Plus Silver Oval 2 Speaker Cables, IC's TBD.
  • gmcman
    gmcman Posts: 1,739
    Excellent work! They look great.

    Coincidentally, my evening started...sorta similarly.

    rcp5ggzphj78.jpg


    I have 8 extra 6510's I plan to glue up, started with these 6. One driver in perfect condition, when I finished I snagged it with my nitrile glove and pulled it off the table. I juggled it for a split second and it hit the floor....magnet shifted and completely frozen now.

    I'm pretty sure my 10yo heard a new word from the other room... :*

    I'm also going to start re-aligning a few original drivers from my 2B's and some spares..now I have an extra to practice on.
  • Faustin
    Faustin Posts: 1,149
    Very nice work. Not very many people would have taken on that project.
  • Mike Reeter
    Mike Reeter Posts: 4,314
    Nice work on those cabinets Jay, quite a transformation!
  • xschop
    xschop Posts: 4,636
    Those went from fugly to eye candy. Nice skills.
    Don't take experimental gene therapies from known eugenicists.