SDA CRS Thermal Resistor??

Malisaw
Malisaw Posts: 5
edited July 2008 in Troubleshooting
Proud owner of a pair of SDA CRS's with stands (50$ at a garage sale! woot!!)

Got them with a nice older Denon Receiver -- They sound fantastic, but i have noticed I can't drive them very hard at all before they protection kicks in and clips the volume considerably.

I read a blurb about a thermal resistor possibly going bad and that this is a common thing apparently..was wondering if anyone could point me towards where I my buy a replacement and any instructions at all about how/where to replace this on/in the speaker. (Bearing in mind I'm *not* very handy.. I punch buttons for a living so screwdriver operation is some how beyond me)...
Post edited by Malisaw on
· Share on FacebookShare on Twitter

Comments

  • george daniel
    george daniel Posts: 12,096
    edited June 2008
    It's called a polyswitch,located on the crossover. Soldering skills are needed,,and they can be had from Polk,just call them,and ask nicely.

    Edit; they look like a little tan disc,,one per board.
    JC approves....he told me so. (F-1 nut)
    · Share on FacebookShare on Twitter
  • dcmeigs
    dcmeigs Posts: 708
    edited June 2008
    Congrats on your find and welcome to the forum.

    Those are very fine speakers. Do you have the interconnect cable? If not, inquire. It's important.

    They polycaps [ed. - polyswitches] can be removed if you can trust yourself not to overdrive your tweeters. I removed mine. It's one less thing in the signal path.

    If you have rowdy friends and crazy late night parties, you need polyswitches.

    Some are tan, but all that I have seen on crs boards were blue, thin and rectangular.
    The world is full of answers, some are right and some are wrong. - Neil Young
    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 50,557
    edited June 2008
    older Denon Receiver

    Hang on. Before you blame the polyswitches, where is the volume level when the poly's kick in? I suspect you are over driving the Denon into clipping. The poly's may be doing exactly what they are designed to do.
    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
  • george daniel
    george daniel Posts: 12,096
    edited June 2008
    F1nut wrote: »
    Hang on. Before you blame the polyswitches, where is the volume level when the poly's kick in? I suspect you are over driving the Denon into clipping. The poly's may be doing exactly what they are designed to do.

    Good eye,,Mr. President,,, ;)
    JC approves....he told me so. (F-1 nut)
    · Share on FacebookShare on Twitter
  • dcmeigs
    dcmeigs Posts: 708
    edited June 2008
    Malisaw wrote: »
    I can't drive them very hard at all


    Humm.
    The world is full of answers, some are right and some are wrong. - Neil Young
    · Share on FacebookShare on Twitter
  • george daniel
    george daniel Posts: 12,096
    edited June 2008
    If you picture the volume control as a clock,,what "time" is it when they trip?
    JC approves....he told me so. (F-1 nut)
    · Share on FacebookShare on Twitter
  • jon s
    jon s Posts: 905
    edited June 2008
    F1Nut is right... I have a Denon 3802 receiver and if I go past 1000-1100 on the dial, the amp clearly clips. It's fine with a 8-ohm load but Denon's amp croaks when driving a 4-ohm load.
    · Share on FacebookShare on Twitter
  • Malisaw
    Malisaw Posts: 5
    edited June 2008
    Wow, OK -- sure wouldn't expect a Denon to clip that early... I'd say it was between 11 & 1 roughly... and certainly not any where close to a "loud" volume. If it's the Denon --- sure makes me miss my old Harmon Kardon! Let me pop down in the basement and get the model number off that Denon.. It's a DRA-635R - don't know anything about it really..except for 20$ I wasn't going to leave it sitting on the table.

    I appreciate all your help folks!

    edited: Oh, and yes I do have the interconnect cable. I ordered one from Polk after I got and read about the speakers a little. Makes a world of difference!
    · Share on FacebookShare on Twitter
  • Malisaw
    Malisaw Posts: 5
    edited June 2008
    I do have a VOM... which certainly doesn't mean I know how to use one :). If some one could tell me how to test the polyswitches I can certainly give it a go.
    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 50,557
    edited June 2008
    Don't bother testing the poly's, your receiver is clipping. Your old HK would be too at that level trying to drive the SDA's. No offense, but you have a lot to learn. So, stick around and get your read on.
    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
  • awe-d-o-file
    awe-d-o-file Posts: 146
    edited July 2008
    the recording and your source; the Denon is likely< I think definitely> clipping and the TR is doing its job protecting the tweeter. Since that thing is only 80X2 it can't overdrive the TR with clean power but only with DC when the Denon clips. "11-1" often overdrives something like that.


    ET

    System: MF Trivista SACD > Placette passive> CJ passive horizontal bi-amp> MF 2500A(LF) MF2100(HF) > 1.2TL's

    Other: Speltz silver Eichmann IC's & speaker wire, Econotweaks Detail Magnifiers, PS Audio P-300(source), R. Gray 600, Al Sekala's AC R/C filters, R. Gray HT PC's, Oyaide R-1's,WPC-Z , M-1, Herbie's & DIY Isolation
    Room: Qty 7 - 4' tall 18" diam. bass traps, Qty 4 - 4' X 2' X 4" panels. All DIY - man my wife is tolerant!
    · Share on FacebookShare on Twitter