LS90 crossover repair/replacement..Noob Warning!!!

cletusjones
cletusjones Posts: 12
edited January 2013 in Vintage Speakers
Total Noob here and this is my first post! I saw a pair of LS90's and a cs350ls(?) at a local thrift and thought they were way too cool looking not to attempt a rescue..especially from local flippers.
Also the price was only 40$ for the set of 3. One Ls90 seems to work fine as does the 350ls; the other LS90 didn't make a sound though. I removed all the drivers and found 3 of the magnets were either off completely or partially off the drivers. I put them back on and retested and now it makes sound and all drivers work but the sound is very faint and lacking any force or power. I suspect the cross over but I know nothing about speakers. Are these replacable/ repairable and even testable ? Any thoughts you guys have are hugely appreciated including if this needs to post to a different forum. Thanks in advance and what I've heard so far from my 1 working speaker, I really like!
Post edited by cletusjones on
· Share on FacebookShare on Twitter

Comments

  • PolkieMan
    PolkieMan Posts: 2,446
    edited January 2013
    Welcome
    Well you got about $300 worth for $40. Take each driver out and at very low volume test it, it's probably the driver not the crossover.
    I would call Polk Customer Service tell them you are a Club Polk member and ask about replacements.
    I like to do my orders with Helen Yarborgh she has been there for over 30 years.
    POLK SDA 2.3 TLS BOUGHT NEW IN 1990, Gimpod/Sonic Caps/Mills RDO-198
    POLK CSI-A6 POLK MONITOR 70'S ONKYO TX NR-808 SONY CDP-333ES
    PIONEER PL-510A SONY BDP S5100
    POLK SDA 1C BOUGHT USED 2011,Gimpod/Sonic Caps/Mills RDO-194
    ONKYO HT RC-360 SONY BDP S590 TECHNICS SL BD-1
    · Share on FacebookShare on Twitter
  • treitz3
    treitz3 Posts: 19,029
    edited January 2013
    Hello, cletusjones and welcome to Club Polk. Congrat's on your latest acquisition. One thing that I'd like to emphasize. Call, don't e-mail and good luck getting them back up and running.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
    · Share on FacebookShare on Twitter
  • cletusjones
    cletusjones Posts: 12
    edited January 2013
    Should be doable as I have all 5 drivers removed now along with the crossover. Never having tested individual drivers before,do you simply crimp alligator clips onto a length of speasker wire..?
    PolkieMan wrote: »
    Welcome
    Well you got about $300 worth for $40. Take each driver out and at very low volume test it, it's probably the driver not the crossover.
    I would call Polk Customer Service tell them you are a Club Polk member and ask about replacements.
    I like to do my orders with Helen Yarborgh she has been there for over 30 years.
    · Share on FacebookShare on Twitter
  • treitz3
    treitz3 Posts: 19,029
    edited January 2013
    Just hook each driver up as you would a speaker......AT LOW VOLUMES.....being certain that the + and - wires will not touch under any circumstance. You can also perform a manual test. Place each driver [except for the tweeter] on a flat surface and without damaging the dust cap, gingerly push down on the cone. If you feel any kind of abrasion or obstruction in the path, that driver is toast. Don't even bother performing the test to see if it will work or not.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
    · Share on FacebookShare on Twitter
  • thsmith
    thsmith Posts: 6,082
    edited January 2013
    yes, hook up to each driver one at a time at low level and see if they sound normal. Be careful not to short the speaker wires or you may damage your amp/receiver/avr.


    I have LS90s and love them. I have a thread posted on starting to tweak mine.

    Congrats
    Speakers: SDA-1C (most all the goodies)
    Preamp: Joule Electra LA-150 MKII SE
    Amp: Wright WPA 50-50 EAT KT88s
    Analog: Marantz TT-15S1 MBS Glider SL| Wright WPP100C Amperex BB 6er5 and 7316 & WPM-100 SUT
    Digital: Mac mini 2.3GHz dual-core i5 8g RAM 1.5 TB HDD Music Server Amarra (memory play) - USB - W4S DAC 2
    Cables: Mits S3 IC and Spk cables| PS Audio PCs
    · Share on FacebookShare on Twitter
  • cletusjones
    cletusjones Posts: 12
    edited January 2013
    Thank you for your welcome..I am pleased I joined! I will call when I have some clue as to what I need or need to do. I've been listening to the good speaker some this morning and I am liking the sound very much. I have a Polk 5.1 speaker set up-minus the sub-in my living room so I am already impressed with Polk products but these seem kind of special sound wise. I am looking forward to using them fully!
    treitz3 wrote: »
    Hello, cletusjones and welcome to Club Polk. Congrat's on your latest acquisition. One thing that I'd like to emphasize. Call, don't e-mail and good luck getting them back up and running.

    Tom
    · Share on FacebookShare on Twitter
  • cletusjones
    cletusjones Posts: 12
    edited January 2013
    Tested them and they all sound pretty much the same, same volume same tone..even the tweeter.. have volume set at 2nd notch from bottom(-52 db)
    thsmith wrote: »
    yes, hook up to each driver one at a time at low level and see if they sound normal. Be careful not to short the speaker wires or you may damage your amp/receiver/avr.


    I have LS90s and love them. I have a thread posted on starting to tweak mine.

    Congrats
    · Share on FacebookShare on Twitter
  • treitz3
    treitz3 Posts: 19,029
    edited January 2013
    Hmmm. Do you happen to notice anything abnormal with the crossovers? I.E. burnt looking components or boards, bulging or leaking capacitors, etc...

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
    · Share on FacebookShare on Twitter
  • westmassguy
    westmassguy Posts: 6,850
    edited January 2013
    Could be crossover problems, the LS90s are pretty easy to upgrade in that respect. Are the connectors for bi-amping in place on both sets of binding posts?
    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/
    · Share on FacebookShare on Twitter
  • cletusjones
    cletusjones Posts: 12
    edited January 2013
    Just noticed a major difference..the bad speakers driver's cones will push in but they are stiff; the good speaker's cones move easily to a gentle touch. Wonder what would trash all 4 equally?
    · Share on FacebookShare on Twitter
  • PolkieMan
    PolkieMan Posts: 2,446
    edited January 2013
    Last thing, before we know it's the crossover.
    Take the driver that seems ok, it worked right, clear sound, exchange it with the same driver in the other speaker system.
    Now if the speaker system still sounds like it did then we know for sure it's not the driver.
    The reason I did not want you to do that first was if the driver had a dead short you could have screwed up the other speaker system too, right.:smile:
    POLK SDA 2.3 TLS BOUGHT NEW IN 1990, Gimpod/Sonic Caps/Mills RDO-198
    POLK CSI-A6 POLK MONITOR 70'S ONKYO TX NR-808 SONY CDP-333ES
    PIONEER PL-510A SONY BDP S5100
    POLK SDA 1C BOUGHT USED 2011,Gimpod/Sonic Caps/Mills RDO-194
    ONKYO HT RC-360 SONY BDP S590 TECHNICS SL BD-1
    · Share on FacebookShare on Twitter
  • westmassguy
    westmassguy Posts: 6,850
    edited January 2013
    cletusjones wrote: »
    Just noticed a major difference..the bad speakers driver's cones will push in but they are stiff; the good speaker's cones move easily to a gentle touch. Wonder what would trash all 4 equally?
    Sounds like the whole speaker was dropped, which separated all the magnets. Best to call Polk Monday morning and see about replacements.
    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/
    · Share on FacebookShare on Twitter
  • PolkieMan
    PolkieMan Posts: 2,446
    edited January 2013
    Ok did not see that . The magnets are rubbing the voice coil. Probably been dropped or smacked around
    cletusjones wrote: »
    Just noticed a major difference..the bad speakers driver's cones will push in but they are stiff; the good speaker's cones move easily to a gentle touch. Wonder what would trash all 4 equally?
    POLK SDA 2.3 TLS BOUGHT NEW IN 1990, Gimpod/Sonic Caps/Mills RDO-198
    POLK CSI-A6 POLK MONITOR 70'S ONKYO TX NR-808 SONY CDP-333ES
    PIONEER PL-510A SONY BDP S5100
    POLK SDA 1C BOUGHT USED 2011,Gimpod/Sonic Caps/Mills RDO-194
    ONKYO HT RC-360 SONY BDP S590 TECHNICS SL BD-1
    · Share on FacebookShare on Twitter
  • PolkieMan
    PolkieMan Posts: 2,446
    edited January 2013
    it may be possible to repair them. realign the magnet.
    http://www.polkaudio.com/forums/showthread.php?141321-SDA-1c-s-that-need-some-help.&p=1863711#post1863711
    look at #27
    POLK SDA 2.3 TLS BOUGHT NEW IN 1990, Gimpod/Sonic Caps/Mills RDO-198
    POLK CSI-A6 POLK MONITOR 70'S ONKYO TX NR-808 SONY CDP-333ES
    PIONEER PL-510A SONY BDP S5100
    POLK SDA 1C BOUGHT USED 2011,Gimpod/Sonic Caps/Mills RDO-194
    ONKYO HT RC-360 SONY BDP S590 TECHNICS SL BD-1
    · Share on FacebookShare on Twitter
  • treitz3
    treitz3 Posts: 19,029
    edited January 2013
    cletusjones wrote: »
    Just noticed a major difference..the bad speakers driver's cones will push in but they are stiff; the good speaker's cones move easily to a gentle touch. Wonder what would trash all 4 equally?

    Ahhh, there is your issue. There should be no friction or stiffness whatsoever. The speaker was dropped. Replace the drivers and you should be good to go.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
    · Share on FacebookShare on Twitter
  • cletusjones
    cletusjones Posts: 12
    edited January 2013
    not sure any of the drivers sounded clear and normal now that I think of it.Never listened to an individual driver out of a speaker before. They all sounded the same but they sounded tinny as individuals much like they did as a group. All five got hashed maybe?
    · Share on FacebookShare on Twitter
  • cletusjones
    cletusjones Posts: 12
    edited January 2013
    treitz3 wrote: »
    Ahhh, there is your issue. There should be no friction or stiffness whatsoever. The speaker was dropped. Replace the drivers and you should be good to go.

    Tom
    Tom..I think this is the aha moment! If the speaker was dropped that would explain the tweeter's magnet running loose in the cabinet as well the upper 2 driver's magnets being loose and somewhat displaced. The point of impact was in the upper half of the speaker!! Now about those new drivers....!
    · Share on FacebookShare on Twitter
  • treitz3
    treitz3 Posts: 19,029
    edited January 2013
    Just call Polk HQ on Monday, they will take care of you. Just an FYI, if you mention that you are member of the Polk forum, they will offer you a small discount. I believe that it's 5% off your purchase but I could be wrong on that.

    BTW, stick around and enjoy the forum. It's a great place to learn about audio, make new friends and discover new music. I hope that this won't be the last we hear from you.

    Tom
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
    · Share on FacebookShare on Twitter
  • cletusjones
    cletusjones Posts: 12
    edited January 2013
    It won't... I'm an audio addict now with an assemblage of rescued vintage gear to further identify me!
    · Share on FacebookShare on Twitter