SDA 2B: One speaker louder than the other

I'm using a pair of SDA2B (completely unmodified) with a Rotel RX-1050 receiver. One speaker is 2-3DB louder than the other. I've swapped the left and right to confirm the right speaker is the louder one so it shouldn't be the source (a Macbook) or anything on the receiver. I confirmed the difference with a pink noise test tone and DB level app. Not the most scientific of ways but good enough to confirm that I'm not a total nut with one blown out ear.

What would cause this? I don't ever remember them sounding like this before. I don't think it's room acoustics as they're in a very square bedroom.

Comments

  • TennManTennMan Posts: 1,052
    Could be a bad mid-woofer. You can test by momentarily connecting a 1.5 volt battery to the speaker terminals and watch to see if they move.
    SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat · Crossover upgrades by westmassguy
    Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
    Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
    Pioneer DV-610AV DVD/CD player
    SDA CRS+ · Hidden away in the closet
  • boston1450boston1450 Posts: 6,363
    Just a thought. Did you try clean the contact where your speaker cables/wires hook into your receiver. Also keep in mind 30+ year old speakers may need refresh on crossover parts. Hope u find issue-feel your pain
    ...
    ...
    Randy / Maine
    SDA-CRS+ 198 tweeters. WMG upgraded crossovers.
    Larry's rings. Stands w/Polk Logo & Spiked nicely
    RTA15TL 198 tweeters. WMG upgraded crossovers.
    Larry's rings. Gloss tops shine. Spiked nicely
    Cs1000p-Yamaha-Parasound-Acurus
    MIT speaker cables-Pangea powercords
  • BlueFoxBlueFox Posts: 12,032
    Is the setup behind both speakers the same, or different? For example, is one speaker close to a corner, and the other near a hallway.
    Bud - Silicon Valley

    Lumin X1
    Sony XA-5400ES SACD
    Pass XP-22 pre, X600.5 amps
    Magico S5 MKII Mcast Rose speakers, SPOD spikes

    Shunyata Triton v3/Typhon QR on preamp, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • boston1450boston1450 Posts: 6,363
    edited May 31
    Deleted
    ...
    ...
    Randy / Maine
    SDA-CRS+ 198 tweeters. WMG upgraded crossovers.
    Larry's rings. Stands w/Polk Logo & Spiked nicely
    RTA15TL 198 tweeters. WMG upgraded crossovers.
    Larry's rings. Gloss tops shine. Spiked nicely
    Cs1000p-Yamaha-Parasound-Acurus
    MIT speaker cables-Pangea powercords
  • Airplay355Airplay355 Posts: 4,294
    edited May 31
    Setup behind both speakers is completely identical. I thought first maybe it was because one wall has a window and that speaker was louder. After the speaker swap, that windowless side is louder.

    Would it have to be the SDA driver that's bad? Both drivers seem like they're making sound just fine without any obvious crackling or anything and move freely when I push in the PR.

    I haven't tried cleaning anything receiver side but figured since the quietness is following the left speaker and not the left side the receiver/source were fine. Am I thinking about that wrong? If the left speaker is swapped to the right, then the right side isn't as loud. If I swap them back, the left side isn't loud.

    Could I check out the crossover and see if anything is damaged by removing the PR? Do crossover bits slowly go bad? I was expecting something to go all at once and I'd lose the tweeter completely or something like that.
  • F1nutF1nut Posts: 42,677
    The electrolytic caps in your speakers are at least 30 years old, way past their lifespan. So, logic dictates that is likely the problem. Swap crossovers and if the issue follows it's time to upgrade the components.
    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

  • Airplay355Airplay355 Posts: 4,294
    I had hoped that wasn't the issue since everything seemed to work fine (until now) even though I knew the components are old. Thanks for the XO swap idea. I'll try that and see how it goes.
  • BlueFoxBlueFox Posts: 12,032
    edited May 31
    Everything wears out over time. Especially mechanical/electronic gear.
    Bud - Silicon Valley

    Lumin X1
    Sony XA-5400ES SACD
    Pass XP-22 pre, X600.5 amps
    Magico S5 MKII Mcast Rose speakers, SPOD spikes

    Shunyata Triton v3/Typhon QR on preamp, Denali 2000 (2) on amps
    Shunyata Sigma XLR analog ICs, Sigma speaker cables
    Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables

    Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
    Three 20 amp circuits.
  • polrbehrpolrbehr Posts: 2,382
    Look at the bright side, if you liked them as they were, they are only going to get better with any mods you do ;). It's not even worth considering NOT doing.
    So, are you willing to put forth a little effort or are you happy sitting in your skeptical poo pile?


    http://audiomilitia.proboards.com/
  • Airplay355Airplay355 Posts: 4,294
    Trying to take the XO out of the left speaker. It seems like there's a bolt/screw holding it in place. I've tried loosening the screw and it just spins. I've tried spinning the XO while holding the screw and it just spins.

    Am I doing something stupid?
  • F1nutF1nut Posts: 42,677
    The glue holding the nut has failed. You'll have to remove the crossover board from the 4 standoffs, then use pliers or the like to hold the nut while unscrewing the bolt. Once you have everything apart resecure the nut with epoxy and wait a day before reassembly.
    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

  • jbail2011jbail2011 Posts: 49
    Could this be a non common ground amp issue?
    Polk Audio SDA 2B TL mod
    Carver M 1.0 MK2 Opt 2
    Carver CT Seven Preamp
    Bluesound Node 2i
    Abacus Aikido Custom Tube Preamp
  • audioluvraudioluvr Posts: 1,334
    Doubtful. If all your drivers and tweeters are working and speaker cables are not out of phase and everything else has been eliminated I'd follow @F1's advice and refresh the crossovers.
    Home System:
    SDA 1C's - Full mod with the help by Dave...
    1000 Va Dreadnought- w/ WireWorld Mini-Eclipse cables
    WireWorld Mini-Eclipse 7 speaker cables
    WireWorld Silver Eclipse IC's
    Cambridge Audio Azur 851N - DAC/Streamer
    B&K Reference 50 Pre/Pro
    B&K M200 Sonata Monoblocks
    BLE-Design 16mm Power Cables
    Denon DVD 2900

    Barn system:
    SDA SRS 2.3's Full mod done by myself
    Carver C-1 pre
    Carver M1.5t
    BluDenso - Bluetooth receiver/DAC
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!