SDA SRS new to me

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Comments

  • xschop
    xschop Posts: 4,636
    Oh boy.
    Don't take experimental gene therapies from known eugenicists.
  • audioluvr
    audioluvr Posts: 5,420
    edited August 2022
    Did you glue a washer on the inside hole so as not to break the plastic frame?

    This is what I did. This is an old pic so the rope seal has been replaced with armacell.

    h9qxsx8001t0.png
    Post edited by audioluvr on
    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
  • F1nut
    F1nut Posts: 49,711
    edited August 2022
    xschop wrote: »
    Unless you perform the foam/frame modification yourself, you'll never reap the benefits of it's function, which absorbs unwanted backwaves, dialing in higher midrange resolution.

    Those backwaves are what drives the passive radiator to produce the low bass. Absorb too much of the backwave and you kill the bass response. Many discovered this when they added too much BH5.

    Edit: a 4x4 or 3x3 piece of BH5 or the like mounted to the rear wall behind each mid-driver results in a slight increase in midrange clarity without affecting the bass response. That is the tried and true perfect balance.

    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

  • xschop
    xschop Posts: 4,636
    Keyword "Midrange"
    Don't take experimental gene therapies from known eugenicists.
  • F1nut
    F1nut Posts: 49,711
    xschop wrote: »
    Keyword "Midrange"

    If you want to sacrifice bass response for midrange have at it, but that's not a balanced speaker.
    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

  • xschop
    xschop Posts: 4,636
    It's actually more balanced and correct in it's midrange, due to the fact that the passive radiators decouple long before the midrange frequencies involved come into play.
    Don't take experimental gene therapies from known eugenicists.
  • Gardenstater
    Gardenstater Posts: 4,137
    I actually got a bit tighter bass, but the Armacell *inside* the basket doesn't absorb much bass. Too thin, way too thin. What bass it does absorb is bass that would've either impacted the rear of the cone, muddying the intended response by out of phase time delayed sound waves and it also probably absorbs some small amount of bass that would've bounced multiple times inside the MW before exiting the windows and affecting the passive with the same muddying effect.

    We're talking minutae here with respect to effect upon bass but I found it was slightly beneficial.

    Mainly midrange clarity as Rob stated.

    Nobody who has done the mod so far has had one single negative thing to say, all positive.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    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
  • F1nut
    F1nut Posts: 49,711
    Rob, the foam inside the basket is too close to the backwaves preventing the bass waves to properly form as bass waves are long and need free space to form. That's why BH5 or the like mounted to the rear wall works.
    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

  • skipshot12
    skipshot12 Posts: 990
    I did not do the washers behind.
    The original gaskets are in excellent shape & still soft.
    Re-used those.

    Keep the tips coming gentlemen.

    My plan is to do a listening session as I do each mod.
    After I get the left speaker done with the 194’s I’d like to absorb the difference then carry on….
  • skipshot12
    skipshot12 Posts: 990
    I’m now on the fence with the foam on the inside of the MW baskets.
    Just read the response on my question about that.

  • skipshot12
    skipshot12 Posts: 990
    Reason I took the Dremel to that lip my thinking was the back of the 194 wasn’t seating with the gasket. Want to make sure I keep the sealed cabinet intact.
    Did the pressure test on the right speaker after replacement of the 4 tweets.
    All is well….
  • skipshot12
    skipshot12 Posts: 990
    edited August 2022
    Two things popped up that made me wonder why the front of the tweeter wasn’t flush like the 2000’s.
    First was it wasn’t flush.
    Second was it started to raise the vinyl covering on the front baffle. Couldn’t accept that so I started looking.
    Luckily it didn’t start to separate.

    Couldn’t live with myself if I screwed something up after the original owner kept them in such beautiful condition.

    And my ocd wouldn’t never have let me sleep tonight 🤣
  • xschop
    xschop Posts: 4,636
    Until a couple large SDA owners report back on any bass attenuation, then I'll agree to disagree. This is a forum BTW. As far as the smaller 5Bs and 8TLs and 1 custom 5Jr set that Ive done, no such bass response loss has occurred, just improved midrange.
    Don't take experimental gene therapies from known eugenicists.
  • pitdogg2
    pitdogg2 Posts: 24,481
    The reason for the washers super glued the the back is to bring the corners up so not to "crush" at the corners. They are not as stiff and just a scosche shorter that the old sl2000, 3000. I needed to also do that on my RD0198's. Some members squished them so much at the corners it may have been creating a vc buzz. That seemed to be a complaint at one time.
  • F1nut
    F1nut Posts: 49,711
    Another possible issue is they can crack at the corners.
    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

  • skipshot12
    skipshot12 Posts: 990
    Installed the other 4 194’s in the left speaker. Got som Al Stewart on a loop for a little break-in.

    Think I’ll try the foam tape on the inside of the mw baskets.

    I’m finding on some recordings the mids will sound like vocals thru a megaphone.
    I’m hoping doing the mw mods will get rid of some of that.

    I would like to get a clearer mid range sound, wondering if a cap upgrade may help?
  • skipshot12
    skipshot12 Posts: 990
    I can see where those corners could crack.
    Seems like the 194’s are a notch down on the quality of the original’s.

    They do sound nice…
    Seem smoother than the 2000’s.
  • F1nut
    F1nut Posts: 49,711
    skipshot12 wrote: »
    Installed the other 4 194’s in the left speaker. Got som Al Stewart on a loop for a little break-in.

    Think I’ll try the foam tape on the inside of the mw baskets.

    I’m finding on some recordings the mids will sound like vocals thru a megaphone.
    I’m hoping doing the mw mods will get rid of some of that.

    I would like to get a clearer mid range sound, wondering if a cap upgrade may help?

    Add BH5 or the like to the rear wall and upgrade the crossovers.
    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

  • audioluvr
    audioluvr Posts: 5,420
    skipshot12 wrote: »
    I’m finding on some recordings the mids will sound like vocals thru a megaphone.
    I’m hoping doing the mw mods will get rid of some of that.

    I would like to get a clearer mid range sound, wondering if a cap upgrade may help?

    Old caps can make music sound like that.
    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
  • skipshot12
    skipshot12 Posts: 990
    Sweet.

    Got to crank some buster poindexter
    Berserk cd today.
    194’s a nice step up.
  • skipshot12
    skipshot12 Posts: 990
    Hats off to those that have done the mw mods.
    Man is that a tedious undertaking.

    First driver done with dynamat & jb weld for the magnets.

    Used way too much jb weld on the first try.
  • skipshot12
    skipshot12 Posts: 990
    Found that some jb on a toothpick, while rolling it on, makes it a lot easier to apply.
  • pitdogg2
    pitdogg2 Posts: 24,481
    skipshot12 wrote: »
    Found that some jb on a toothpick, while rolling it on, makes it a lot easier to apply.

    popcicle or craft sticks work to.
  • skipshot12
    skipshot12 Posts: 990
    Tanks for the tip.
    Trip to ace to see what I can find to spread the jb.

    Just waiting on the BH 5 for the cabinet and the armacell for the insides of the baskets.

    I like what I read about the inside basket treatment some of you’s have reported on.
    I would really like to get more definition in the midrange.

    I like the idea of mechanical upgrades. I’m a tinkerer…..
    Will save the electrical upgrade of the crossover for last.

    This is a fun trip for me to play mad scientist 😬
  • F1nut
    F1nut Posts: 49,711
    Just waiting on the BH 5 for the cabinet and the armacell for the insides of the baskets.

    Do one or the other, but not both and I strongly recommend doing the BH5.
    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

  • skipshot12
    skipshot12 Posts: 990
    Tanks F1.

    First MW hanging to dry...
    kpjhtoncfgsr.jpg
  • skipshot12
    skipshot12 Posts: 990
    Dynamat & JB weld....

    n4gtegve61ce.jpg


    1kw1hn1t9a4l.jpg
  • skipshot12
    skipshot12 Posts: 990
    Way too much JB but came out nice after a shart-ton of removing the excess. Looks like it could survive a fall from the Eiffel Tower but wasn't worth the effort.
    Did the magnet closest to the basket with a toothpick to apply and am getting the hang of it. Took me two days on the first driver.
    Ended up with JB Weld on everything, body, shirt, eating doily, cocktail table etc.
    Got the stink eye from the whiff. Will be more careful on the rest.

    Really enjoying the journey...
  • skipshot12
    skipshot12 Posts: 990
    Another mod that I found while doing searches, sealing the cabinet. Sounds worthwhile.

    Looks like a crazy long time, from here, to completion seeing the amount of work ahead.
    My whiff keeps telling me a little at a time and it won't seem so overwhelming, not looking at the whole picture will help to keep me going.
    Take small steps for each mod and before long, it's done.

    Time for another frosty beverage....
  • F1nut
    F1nut Posts: 49,711
    edited August 2022
    Ima gonna add to your long list.

    The end caps are attached with threaded studs. The nuts tend to loosen over time, which will result in an air leak. So, be sure to check if they are loose. I recommend adding a lock washer to prevent the nuts from ever loosening again.
    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