SDA 1B

Recently aquired. All stock, original interconnect cable.
Very warm sound. Mid frequencies subdued compared with various other speakers.
I decided to replace all the Capacitors, and redo the interconnect with Speak-on connectors.
First listen, they sound different.
The "SDA effect" is diminished, and the mid frequencies are much more pronounced, I don't find myself turning it up as loud now to hear....
And the bass in diminished. Well, maybe diminished is not the right word....I think the bass is still there, but not as pronounced because there is more presence? I keep finding myself wanting to turn the treble up.
I'm not sure I like the change.
Parts used, because on a budget....
Dayton metalized poly for HF board
Dayton non-polarized electrolytic for LF board
Dayton audio grade non inductive resistors
Poly switch removed with jumper. Any thoughts and advice will be appreciated
«1

Comments

  • pitdogg2
    pitdogg2 Posts: 24,474
    edited January 2019
    Start over


    Not all speak-on connectors are air tight. That would be a problem for bass in a sealed system. How did you wire on the connectors? The wire on the big blade on one speaker is opposite on the other speaker (small blade) and vice versa. So if you put big blade wire on 1+ on one side, then it needs to be on 1- on the opposite side. Using a jumper instead of a .5 ohm resistor makes the tweeters more pronounced (hotter).


    did you have air leakage in the cabinets? Are your gaskets good?
  • F1nut
    F1nut Posts: 49,704
    Not a good choice of capacitors.

    Sounds like you may have connected something wrong. The sound stage and bass should be better than stock.
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  • Coupe1985
    Coupe1985 Posts: 34
    edited January 2019
    I sealed around the pins of the speak-on connector with hot glue after I soldered the wires on.
    I sealed them to the cabinet with black windshield sealing cord
    I wired the plugs according to the diagram in the SDA manual, and it appears to be working, if I unplug the cord the outside drivers shut off
    The cabinets pass the 3 second test when pushing on the passive radiator
  • pitdogg2
    pitdogg2 Posts: 24,474
    well most of us here would not of went with any electrolytic's . How many hours you have on the new caps? There are definitely better film caps that are not much more than the Daytons. If someone was to use Daytons it would not of been in the high pass section for most of us. Clarity cap is one you can use for a less expensive cap. Most of us like Sonicaps, they just seem to go so well with SDA's. How far off from the original value are the daytons?
  • I get that I went against the norm with regards to the Caps. But what I used is still higher quality and tolerance than the originals.
    In the HP section the Caps were exact matches
    The LP Caps were not....
    The 55 uf went to 50uf
    The 130 uf went to 125uf
    The 34 uf went to 33uf
    I am not opposed to doing it again with higher quality parts, also plan to buy rdo194's in near future
  • I should also advise that I did not put the 750pf Caps back in
  • Just noticed that I took out a 4.4 from left speaker, and a 4.0 from the right......what's up with that?
  • xschop
    xschop Posts: 4,635
    Assuming the tweeters are SL2000's, do they look clear or cloudy/opaque?
    Reason being the opaque ones are so old/oxidized that it indeed affects their sound IMO. The 5uf cap differences will affect a Small portion of the frequency range.
    Don't take experimental gene therapies from known eugenicists.
  • Yes, they are sl2000's. Not cloudy, can see magnet and felt behind the domes
    They do ALL look like they were pushed in at some point, and then pulled back out.
    All measure about 7.7 ohms
  • pitdogg2
    pitdogg2 Posts: 24,474
    Coupe1985 wrote: »
    I should also advise that I did not put the 750pf Caps back in

    Good move they're no longer needed with better caps.
  • xschop
    xschop Posts: 4,635
    Hopefully you have some good amplification. Otherwise be thankful F1nut is in timeout.
    Don't take experimental gene therapies from known eugenicists.
  • pitdogg2
    pitdogg2 Posts: 24,474
    Coupe1985 wrote: »
    I get that I went against the norm with regards to the Caps. But what I used is still higher quality and tolerance than the originals.
    In the HP section the Caps were exact matches
    The LP Caps were not....
    The 55 uf went to 50uf
    The 130 uf went to 125uf
    The 34 uf went to 33uf
    I am not opposed to doing it again with higher quality parts, also plan to buy rdo194's in near future

    Ok so what were the +/- tolerance with the new caps? 10% ? Most of the better caps are about a 3% tolerance i believe.
    The reason i ask i believe the old were also 10%+/- so once you change value and then have that 10%+/- also it has a bigger possibility to really change the crossover.
  • The poly Caps are 3% the electrlytics are, well, I don't remember off hand, and the resistors are 5% IIRC
    xschop wrote: »
    Hopefully you have some good amplification. Otherwise be thankful F1nut is in timeout.

    I have a Nikko Alpha 440, and a Crown XLS2502. Mostly use the Crown
  • pitdogg2
    pitdogg2 Posts: 24,474
    edited January 2019
    How many hours have you put on the xo since rebuild?
    Most of us will use Vashay-Mills 1% 12 watt wirewound resistor. They are very cheap yet very good. Much better than the ceramic.
  • pitdogg2 wrote: »
    How many hours have you put on the xo since rebuild?
    Most of us will use Vashay-Mills 1% 12 watt wirewound resistor. They are very cheap yet very good. Much better than the ceramic.

    Only about 2 or 3 hours on them. Mostly at low volumes.
    I was having a very hard time finding all the parts in one location, and with Sonicaps and Mills resistors I was at around $300. Almost the cost of the speakers.....was trying not to go that route, but if need be I will
  • audioluvr
    audioluvr Posts: 5,420
    Your components are not what we here would recommend or use and the values are all over the place making it virtually impossible for us to help you. What we do here on the Vintage forum is more of an investment to restore our speakers to better than new (hopefully...). The good thing about duplicating what's widely accepted here is all the research and development done prior. Essentially you don't have to reinvent the wheel.
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  • gmcman
    gmcman Posts: 1,739
    Coupe1985 wrote: »
    ... with Sonicaps and Mills resistors I was at around $300. Almost the cost of the speakers.....was trying not to go that route, but if need be I will

    The end result will likely be greater than a $600 pair of speakers....well worth it.
  • TennMan
    TennMan Posts: 1,261
    I would check for all the drivers being in phase with a 1.5 volt battery. Disconnect the interconnect cable before doing the test. All the drivers should move outward when you momentarily connect the battery (observing polarity) to the speaker terminals. If any of the drivers are out of phase it would explain the diminished bass and SDA effect.
    • SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
    • Crossover upgrades by westmassguy
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  • TennMan wrote: »
    I would check for all the drivers being in phase with a 1.5 volt battery. Disconnect the interconnect cable before doing the test. All the drivers should move outward when you momentarily connect the battery (observing polarity) to the speaker terminals. If any of the drivers are out of phase it would explain the diminished bass and SDA effect.

    That's the 1st thing I though of. All 4 move out with battery.
    I guess I'm just going to bite the bullet and go the whole 9 yards. Going to build the crossovers from scratch with the recommended components and glue and dynamat the drivers and secure with bolts and hurricane nuts. Why not? It's only money, and money doesn't make beautiful music like the Polk's do
  • pitdogg2
    pitdogg2 Posts: 24,474
    edited January 2019
    It takes a lot more hours than that before most poly caps burn in. You need to give it time.

    Yes we never find it all in one location. No biggie we invest in our speakers knowing full well we will never get 100% of that investment back. Consider it lucky if you get 50% back.
  • tonyp063
    tonyp063 Posts: 1,044
    ^^^^
    This.

    @Coupe1985 , pay attention to wessmassguy. He knows of what he speaks.
  • Make sure the grounds leads for the stereo and dimensional woofer harnesses weren't mixed by mistake. It can happen easily if they were not wire tied originally.
    It can cause odd imaging, and the interaural crosstalk cancellation will not be functioning properly.

    Are you referring to the harness that connects to the drivers? The SDA handbook only shows the wire colors for the 1C.....white=ground on dimensional drivers, and green=ground on stereo drivers. Correct?
  • westmassguy
    westmassguy Posts: 6,850
    Coupe1985 wrote: »
    Make sure the grounds leads for the stereo and dimensional woofer harnesses weren't mixed by mistake. It can happen easily if they were not wire tied originally.
    It can cause odd imaging, and the interaural crosstalk cancellation will not be functioning properly.

    Are you referring to the harness that connects to the drivers? The SDA handbook only shows the wire colors for the 1C.....white=ground on dimensional drivers, and green=ground on stereo drivers. Correct?

    I've seen all manner of wire color combinations, however black is always positive for the stereo woofers, and blue is always positive for the dimensional woofers. The grounds may be all white or all green, or mixed.
    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
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  • Schurkey
    Schurkey Posts: 2,100
    edited January 2019
    Coupe1985 wrote: »
    I get that I went against the norm with regards to the Caps. But what I used is still higher quality and tolerance than the originals.
    I get that. New electrolytics have got to be better than ancient electrolytics. That's not what I chose to do, but I can see the validity if price is a big concern.
    Coupe1985 wrote: »
    In the HP section the Caps were exact matches
    The LP Caps were not....
    The 55 uf went to 50uf
    The 130 uf went to 125uf
    The 34 uf went to 33uf
    I am not opposed to doing it again with higher quality parts, also plan to buy rdo194's in near future
    BOTH SDA capacitors 55/50 and 130/125 are 5uF shy as installed, 10uF total. The 130 + 55 caps are wired together to provide 185uF. You've got 175uF. You'd have been better off to get a 125 and a 65, or a pair of ~90uF per cabinet. I bought two pair of 91uF film caps from ERSE--182uF--to stuff in my 1Bs.
    http://www.erseaudio.com/Products/PulseXAll/MPX25-03-91-00

    34/33 is inconsequential.

    Although some folks disapprove, there's a long thread about using RD0-198s in the 1Bs, based on comments by Matthew Himself. I did. You'll need a pair of 5.8uF caps for the HF crossover (5.6uF is easier to source, and acceptable.)
    http://www.erseaudio.com/Products/PulseXAll/MPX25-03-5-60
    The thread is 6 pages long, and you can pretty much disregard the first three pages. Here's page 6:
    https://forum.polkaudio.com/discussion/74946/sda-srs-2-crossover-parts-list


    Coupe1985 wrote: »
    I wired the plugs according to the diagram in the SDA manual, and it appears to be working, if I unplug the cord the outside drivers shut off
    CHECK YOUR WIRING CONNECTIONS. That is NOT correct. This is probably why your bass is lacking. The SDA drivers should be reinforcing the bass below a certain frequency (100 hz???) based on the giant inductor behind the crossover board. The SDA drivers should continue to provide sound (bass) even with the SDA interconnect disconnected.

    Wild Guess: Open circuit on the SDA inductor--bad solder joint, broken wire, something like that.

    Post edited by Schurkey on
  • Schurkey
    Schurkey Posts: 2,100
    xschop wrote: »
    be thankful F1nut is in timeout.
    What'd he do? I disagree with F1nut from time to time, but he's a valuable member here.

  • Schurkey
    Schurkey Posts: 2,100
    Coupe1985 wrote: »
    Just noticed that I took out a 4.4 from left speaker, and a 4.0 from the right......what's up with that?
    Polk ran out of the correct part, substituted something "close"???

    Factory Mistake???

    Good thing those caps are no longer installed.

  • westmassguy
    westmassguy Posts: 6,850
    You cannot "TL" 1Bs, or SRS-2s simply by changing the 4.4uf to 5.8uf. It wasn't correct then, and 9 years later, it's still not correct.
    Home Theater/2 Channel:
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    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/
  • In the quest to do this again the right way, I am thinking about crossover boards from Gimpod?
    Are they one board fits all, or only SRS?