Need Help Troubleshooting Polk 7

I have a pair of early Polk 7s: Peerless tweeters, single fuses on back. One of the speakers works flawlessly. But the other one exhibits an irregular break-up of high frequencies. Seems like it needs a certain combo of freq and volume to occur. It's not a drop out of sound, but more like a raspy sound or distortion in audio quality.

It's hard to replicate, but something is not right. Sometimes I find myself thinking it healed itself, only to find that it reappears. I've switched channels, tried diff amps, and different sources.

Just looking for some thoughts on where to look, or what it might be. I was first going to clean the connections at the binding posts, fuses, and drivers. Anything else to check/clean?

I always thought these Peerless tweeters either worked or they didn't. Is it possible it could be an internal problem with the tweeter?

Thanks, in advance, for any suggestions!

Comments

  • pitdogg2pitdogg2 Posts: 17,961
    edited August 2020
    I was first going to clean the connections at the binding posts, fuses, and drivers. Anything else to check/clean?
    I'd start with that thought


    I bet the wire is corroded at the fuse block as well
  • GardenstaterGardenstater Posts: 1,662
    My fuse wires are thoroughly sealed with gobs of hotmelt on the inside of the cups. I have no clue what the attachments of the wires to the fuse block look like but I will soon find out when I put Cardas Binding Posts in and 11.5 gauge Cardas Litz. My Peerless tweeters were soldered but if yours have fastons you could check and clean those connections as well. If they do have fastons it should be relatively simple to swap the tweeters and see if the problem stays with the speaker or follows the tweeter. If you want to switch to fastons and do the experiment anyway, you may have to be careful like I did and cut the tweeter wires about 1 in. from the tweeter and put on a male faston on that wire and a female faston on the wire coming from the crossover. Gold plated brass ones (at least for the females) are available from the Auto Parts stores. I think it's Dorman brand and I forget if it was PepDudes, Advance, or Autozone that I found them. For the tweeters the proper size is 7/64" (2.8mm). You can get some overpriced ones from Partsconnexion.com The WBT's.

    To clean the fuseholders and other connections, 2000 grit paper works well. Or did I use 3000? Either one is fine.
    George / NJ

    Polk 7B main speakers, most mods comp. (1979, orig owner)
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