SDA SRS2 '86 blade-blade. Budget upgrade. Looking for an advice.

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Hi guys.

I was happy with my SDA 2b in excellent condition for two years. I changed twitters for RD0194 early on and prepaid the crossovers upgrade for this April. But as it happens, I stumbled across SDA SRS2 for a very good price in only 140mls drive.

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So here we are. SRS2 will be in my main setup as stereo speakers for music and front for HT. 2b's will be sold later this year after the SRS2 rebuild is finished.

I had no experience disassembling vintage Polks and decided to be careful, so I carefully removed all the speakers to disconnect all the wires.

Turns out, they're not 8x MW6509, but 6x MW6509 original and 2x MW6510 from SRS2 1989.

Few questions:
1. What would you suggest doing with mids: (1) keep those I have and use MW6510 as SDA speakers on two sides matching place or (2) find a way to swap for MW6509 or (3) smth else?
2. Is there a reason to change binding posts other than esthetics?
3. I read in the past about nuts for screws. Is it critical to add those? Can you recommend a place to buy it?
4. What else could be useful to do while boxes are empty?
5. Are there any important things to remember while assembling everything back?

Few photos:
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Comments

  • F1nut
    F1nut Posts: 50,086
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    Upgrade the 2B's and sell the SRS2
    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

  • alexanikin
    alexanikin Posts: 105
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    F1nut wrote: »
    Upgrade the 2B's and sell the SRS2

    Thank you for the advice. I tested those back to back: in my room with my equipment, and for my ears, I like SRS2 better.
  • F1nut
    F1nut Posts: 50,086
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    With the 2B you can upgrade them to use the RD0198-1, which is a much better tweeter than the RD0194-1 that the SRS2 has to use. The 2B, with the AI-1 or Dreadnought can be driven with non-common ground amplification, which cannot be done with the blade/blade SRS2. The 2B has a better balanced presentation verses the rather thick sound of the SRS2.

    So, there ya go...
    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
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    I'll have to confirm--it's been years since I played with this stuff--that I have extra 6509s. If I can find 'em, I would trade for your 6510s. I have a pair of SRS2 pin/blade speakers that have been ignored for about six or seven years now.

    The SRS2 blade/blade crossovers are identical to the SDA 1B crossovers except for the value of one resistor in each cabinet. You'd do well to check-out "inspiredsports" thread from when he updated/rebuilt his SRS2 crossovers. The first half of that thread is polluted with bad information. Things clear up in the second half.

    https://forum.polkaudio.com/discussion/74946/sda-srs-2-crossover-parts-list/p1
  • F1nut
    F1nut Posts: 50,086
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    Clear as mud.
    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

  • Gardenstater
    Gardenstater Posts: 4,281
    edited March 2023
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    "1. What would you suggest doing with mids: (1) keep those I have and use MW6510 as SDA speakers on two sides matching place or (2) find a way to swap for MW6509 or (3) smth else?"


    Definitely (2). Vastly different T/S Parameters between 6509, 6510, and 6511. 3rd Gen blade-blade was 4x 6509 and 4th Gen pin-blade was 2x 6511(stereo) plus 2x 6510 (dimensional) and MUST have had a different crossover.

    1 Driver Type Q BL Compliance DC Resistance Fs

    3 MW 6501 1.470 5.96 N 3.250 E - 3N/M 7.750 Ohms 31 Hertz
    4 MW 6502 1.970 5.16 N 1.470 E - 3N/M 3.520 Ohms 44 Hertz
    5 MW 6503 1.820 5.24 N 3.550 E - 3N/M 6.540 Ohms 29 Hertz
    6 MW 6509 2.100 4.57 N 3.540 E - 3N/M 8.970 Ohms 30 Hertz
    7 MW 6510 1.390 6.32 N 3.410 E - 3N/M 6.570 Ohms 31 Hertz
    8 MW 6511 1.405 4.34 N 3.496 E - 3N/M 3.130 Ohms 29 Hertz
    9 MW 6512 1.905 4.99 N 1.588 E - 3N/M 3.466 Ohms 40 Hertz
    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
  • xschop
    xschop Posts: 4,837
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    Has anyone else actually tested their 6511's to be @ 3.1 ohms?
    I've tested all to be @3.5 ohms.
    Don't take experimental gene therapies from known eugenicists.
  • alexanikin
    alexanikin Posts: 105
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    Schurkey wrote: »
    I'll have to confirm--it's been years since I played with this stuff--that I have extra 6509s. If I can find 'em, I would trade for your 6510s. I have a pair of SRS2 pin/blade speakers that have been ignored for about six or seven years now.

    I would be happy to swap. Let me know if find them please.
  • Schurkey
    Schurkey Posts: 2,100
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    xschop wrote: »
    Has anyone else actually tested their 6511's to be @ 3.1 ohms?
    I've tested all to be @3.5 ohms.
    The new + and - test lead pair, and the original test lead pair, of my Fluke 88 multimeter both have .2 ohms resistance.

    If yours are the same, a reading of 3.5 ohms minus .2 ohms in the test leads would be 3.3 ohms for the drivers. Doesn't seem so far "off" considering the mass-market nature of the drivers.

    (Unless you put the ends of the leads together, and zero the meter before testing the driver's coil.)
  • xschop
    xschop Posts: 4,837
    edited March 2023
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    Test leads were taken into account and lowest reading was 3.4 ohms.
    I've got another burnt coil, original 6500 that I'm going to install a 3.5 ohm coil in. It's compliance is the same already as suspensions are identical, and BL should be the same as 6511 when done.

    MW 6510 1.390 6.32 N 3.410 E - 3N/M 6.570 Ohms 31 Hertz
    MW 6511 1.405 4.34 N 3.496 E - 3N/M 3.130 Ohms 29 Hertz
    Don't take experimental gene therapies from known eugenicists.
  • alexanikin
    alexanikin Posts: 105
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    Hey guys, is there any interest in following the upgrade process of one more pair?

    I mean, so many threads show essentially the same process for different models. I have my joyful moments and am happy to share my thoughts here.
  • Gardenstater
    Gardenstater Posts: 4,281
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    I'm interested!
    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
  • xschop
    xschop Posts: 4,837
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    Carry on my wayward son.
    Don't take experimental gene therapies from known eugenicists.
  • alexanikin
    alexanikin Posts: 105
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    Schurkey wrote: »
    I'll have to confirm--it's been years since I played with this stuff--that I have extra 6509s. If I can find 'em, I would trade for your 6510s. I have a pair of SRS2 pin/blade speakers that have been ignored for about six or seven years now.

    @Schurkey thank you for the exchange and for all your advice.
  • Schurkey
    Schurkey Posts: 2,100
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    I've been sick for well over a week. I've received the '6510s, but haven't even opened the box yet. Glad you got the '6509s in good condition.
  • alexanikin
    alexanikin Posts: 105
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    Schurkey wrote: »
    I've been sick for well over a week. I've received the '6510s, but haven't even opened the box yet. Glad you got the '6509s in good condition.

    Can't like your message. Get better!
  • alexanikin
    alexanikin Posts: 105
    edited April 2023
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    After crossovers have been sent to a guy for the upgrade, I've started reading this forum and a little bit of the internet to come up with a list of what I want to do with these speakers and stay at a moderate budget.

    The first thing was to find information about a successful TL upgrade for SRS2 b/b, but it turned out the guy upgrading my crossovers had this experience before.

    The grocery list:
    1. RD0198 x4 from midwestspeaker
    2. Hurricane nuts for #8-32 screws (link)
    3. Internal Threads for #8-32 screws, 10mm length (link)
    4. For mids and PRs: button head socket cap screws for 3/32" hex key, black, 1" long (list)
    5. For tweeters: flat head socket cap screws for 3/32" hex key, black, 1" long (list)
    6. For tweeter magnets: flat head socket cap screws for 3/32" hex key, black, 1/4" long (list)
    7. Washers #8 (link)
    8. Armacell TAP18230 foam for diy gaskets (link)
    9. Dynamat Xtreme (link)
    10. Loctite Epoxy x2 (link)
  • alexanikin
    alexanikin Posts: 105
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    Some introduction and disassembling process.

    I picked up these speakers in Fresno from a cool guy Ted, who wanted a project, but never had time to start. The first set of speakers in my life, which I can't move on my own. I mean, I can, but it is not fun at all ;)
    l143s1fwnjs5.jpg

    I decided to try them for a few days before disassembling. To taste what to expect later.
    0c4fqv7yg4au.jpg

    The speakers had several problems:
    1. On the right speaker, one tweeter was a bit noisy
    2. On the left one the top wood piece was wobbly
    3. And mids had a different sound

    But still, I liked these even better than my existing 2B, while I enjoy a lot.

    During disassembling, it became obvious that nobody ever opened the right speaker, but the left one had been visited a few times. The PR bolt look pretty strange to me; silver are from the left.
    msmdsrihdlm7.jpg

    Naturally, hurricane nuts were the first thing to do. The pretty easy procedure takes only diligence and a bit of patience.
    zsxf9jqzl5ij.jpg
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    There was one surprise: a slat beside two holes for the lower tweeter. For these decided to use internal threads instead of hurricane nuts.
    olglhuy621nz.jpg

    Here is the result:
    zrdwcx7x1va5.jpg

    Playing with drivers is next.
  • alexanikin
    alexanikin Posts: 105
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    7/64" drill bit was used for hurricane nuts
    1/4" drill bit was used for internal threads

    And for all the screws, I had to buy 3/32 bit, cuz I had none capable of tightening over 50 nuts into the MDF box.

    Does anybody know if these feet are genuine?
    t1vr6s2c25zu.jpg


  • F1nut
    F1nut Posts: 50,086
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    Yes
    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

  • alexanikin
    alexanikin Posts: 105
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    F1nut wrote: »
    Yes

    Would you suggest to keep or change for something else?

    I have hardwood floors.
  • F1nut
    F1nut Posts: 50,086
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    Spikes with floor discs.
    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

  • alexanikin
    alexanikin Posts: 105
    edited May 2023
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    Started with epoxy for the magnets. I thought It would be much more complicated, but it was easy and no mess. Approx 3/4 of epoxy tube and an hour per each side of the magnet for all eight drivers.

    as1qfyeenvg8.jpg
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    xcl7kzd5ou0y.jpg

    Dynamat and new gaskets took about 6-7 hours in total for 8 mids and 2 PR. The gaskets on all drivers were in a different condition, so I decided to change them altogether. Don't have photos of the process. I simply cut templates for one mid and pr, and then multiplied accordingly.

    8b39tu6bya14.jpg
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    qejtotehnb6l.jpg

    Now it tweeters' turn.
    These gaskets were okay, so we kept them. Thanks to one thread here, which I forgot to bookmark, I noticed that rd0198 is for a different screw head (flat) and possibly needs washers. Spent some time comparing sl2000 and rd0194 frames and even thinking about two washers per hole, but I passed.

    Three drops of a noname super glue + M8 washer per hole.
    hdt3ukbhp9xp.jpg

    Honestly, the original Philips screws bugged once I tried new screws matching those for mids, but flat head instead of buttons. I just don't like this mismatch. The screws are #8x32 1/4" and I found the matching set.
    crnbmu2uzdod.jpg
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    Expecting crossovers to arrive back home in the next 10 days.





  • skipshot12
    skipshot12 Posts: 1,075
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    Nice looking job on the Dynamat.
  • alexanikin
    alexanikin Posts: 105
    edited May 2023
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    alexanikin wrote: »

    I decided to try them for a few days before disassembling. To taste what to expect later.
    0c4fqv7yg4au.jpg

    Few words about my current main setup. For the last couple of years, I have tried different digital and analog music sources and different movie reproduction approaches. The current system is unified for both while considering the convenience for other people living with me who don't want (or can't) to learn how to use a complicated set of electronics. So analog sources and hi-res stuff have been stripped off for good.
    Now AppleTV remote is the only one used to control everything.

    1. Sources: NAS + Plex for movies and music + Apple Music
    2. Streamer: Apple TV and AirPlay2 over it. Limited to 48/24, but it is just enough for me
    3. Receiver: Yamaha TSR-700
    4. Amplifier for fronts: Parasound Halo A23
    5. Front speakers: Polk SDA 2b -> SRS2TL
    6. Center speaker: Polk Signature S35
    7. Surround Speakers: Polk Signature S15
    8. Interconnects: Audioquest Diamondback
    9. Speaker cables: handmade 9AWG based on a copy of Kimber Kable 12TC from Aliexpress

    nxnfzqvilyub.jpg

    I love this setup.



  • xschop
    xschop Posts: 4,837
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    Are you going to foam-frame the drivers?
    Don't take experimental gene therapies from known eugenicists.
  • alexanikin
    alexanikin Posts: 105
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    xschop wrote: »
    Are you going to foam-frame the drivers?

    Do you mean the foam inside the drivers, like here?
  • xschop
    xschop Posts: 4,837
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    Yep, some nice gains to be had there.
    Don't take experimental gene therapies from known eugenicists.
  • alexanikin
    alexanikin Posts: 105
    edited May 2023
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    tbh, I didn't consider doing this. Will take a look starting here.

    @xschop, do you know, if the same foam used for gaskets is good for the insides of the drivers? Is it only for mids or for PRs too?
  • xschop
    xschop Posts: 4,837
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    Just do the mids. The best foam is open-cell at least 3/16" thick. It's even easier (for me) to use bare foam and a thin layer of Power-Grab. Allows for easy placement and longer adjustment time.
    Don't take experimental gene therapies from known eugenicists.