SDA 1 Cabinet rattle

Options
michael1138
michael1138 Posts: 1
in Vintage Speakers
Hi Everyone,

My right channel SDA 1 speaker has developed a rattle at loud low frequencies, typically experienced with action movie soundtracks.

I can't complain, this is the only problem I've noticed with these speakers in 35+ years.

Any recommendations for diagnosis and repair?

Many thanks,
Michael
· Share on FacebookShare on Twitter

Comments

  • Gardenstater
    Gardenstater Posts: 4,203
    Options
    You probably have a magnet that shifted and voice coil may be rubbing at certain low frequencies with prolonged tones. I'd check them all carefully with fingers spaced around the dust cap and listen/feel for scraping.
    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
    · Share on FacebookShare on Twitter
  • Gardenstater
    Gardenstater Posts: 4,203
    Options
    ^^Now that coffee has taken affect........a rattle could also be a cracked or torn spider
    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
    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 49,856
    Options
    michael1138 wrote: »
    Hi Everyone,

    My right channel SDA 1 speaker has developed a rattle at loud low frequencies, typically experienced with action movie soundtracks.

    I can't complain, this is the only problem I've noticed with these speakers in 35+ years.

    Any recommendations for diagnosis and repair?

    Many thanks,
    Michael

    A rattle sound is one thing, a popping sound is another.
    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

    · Share on FacebookShare on Twitter
  • Schurkey
    Schurkey Posts: 2,100
    edited August 2022
    Options
    A rattle at low frequencies/high volume seems to me to be more-likely a cabinet air-leak, leading to over-excursion of the midwoofers. Easily and non-invasively tested via the usual "push the bassive radiator, see how long it takes for the midwoofers to retract."

    Otherwise, I think you're gonna pull some drivers out, maybe move or remove the Dacron, and look for loose bracing, or wires rattling against the inside of the cabinet.

    Remember, after 35 years, those speakers need some repairs/updates. The Dacron is almost certainly pulled down by gravity and needs to be lifted back up into proper position, and the electrolytic capacitors are WAY beyond their expected service life. There's plenty more that can be done to improve them, but those two are essentially guaranteed to need attention.
    · Share on FacebookShare on Twitter
  • skipshot12
    skipshot12 Posts: 1,017
    Options
    Probably not related but…
    I had a rattle @ certain frequencies in one of my kappa 8’s.
    Took out the woofer to have a look. Found one of the inductors was loose, one edge not attached.
    A little metal set cured the rattle.
    · Share on FacebookShare on Twitter