lkahn Posted January 10, 2003 Share Posted January 10, 2003 Help! I recently bought an old pair of BK's that (as I attempt to decipher the serial number) seem to be from '82, with AA networks. One of them sounds just plain bad, and I don't know where to start looking for the problem. The bad one: has good bass seems to have all 3 drivers working very muddy, distant, lifeless, mids and highs If these were dynamic drivers, I'd say the cones were blown. I have no experience with horns, so I can't say what's going on. I've checked phase, I've switched the (300B)amps, but no change. My question: Do I start by looking at the drivers or the networks? As you can tell, I'm no DIY'er when it comes to electronics. Thanks for your help. lkahndc@prodigy.net Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted January 10, 2003 Share Posted January 10, 2003 Look for leakage around the oil filled caps on the crossover, see if any leads are touching or disconnected/unsoldered, tighten down all the screws on the crossover as well. Remove any dust with a small paintbrush or with a can of compressed air. Get some Caig's D5 DeOxit to spray on the spade lugs and contact points. Check the polarity of the squawker and tweeter as connected to the crossover + (red stripe) to +, - (solid white) to - usually when drivers blow they emit no sound at all. Try moving the speaker that sounds bad over and connect it to the leads where the other speaker is hooked up. Perhaps it is not the amp, but the preamp or source that is generating the bad sound out of that particular channel. See if any of these suggestions work for you. The squawkers unscrew and you probably have spring terminals on them, try swapping the midrange drivers and see if the sound in the one speaker improves any. Let us know how you make out. Quote Link to comment Share on other sites More sharing options...
lkahn Posted January 10, 2003 Author Share Posted January 10, 2003 I get the feeling you've done this before! My mid drivers do have spring terminals, so if your other suggestions don't lead to a quick fix, I will try swapping them. I'll let you know. Thank you. lkahn. Quote Link to comment Share on other sites More sharing options...
lynnm Posted January 10, 2003 Share Posted January 10, 2003 I concur with Frzninvt the problem is with the signal path to the midrange driver. The most likely problem is a poor connection somewhere although there is the ( rather unlikely) possibility of a blown midrange driver. I would rough up all of the connections to the speaker - right from the main inputs up to and including the crossover outputs. I would also examine the connections at the Midrange driver to rule out at bad joint. Be sure also to check out the connections at the rear of your amp. My best guess remains however that there is something impairing the signal from the crossover to the midrange driver. Quote Link to comment Share on other sites More sharing options...
WMcD Posted January 11, 2003 Share Posted January 11, 2003 Natually, all the advice given above is very good. When I have a similar problem, I first try to "go back to basics". It is an annoying phrase used by pedants who have no real technical insights. Still, sometimes it works. Allowing the pedants to be smug, for no reason. So do check all the wires are where they are supposed to be, and the connections are clean. None the less, I certainly agree that the most audible problem is likely to be with the midrange. Is there any chance the wires to the midrange and tweeter got switched? The proper connection should be obvious from the labels on the crossover. Again, please let us know what you find. Gil Quote Link to comment Share on other sites More sharing options...
WMcD Posted January 11, 2003 Share Posted January 11, 2003 The attached may help you understand the crossover. Gil Quote Link to comment Share on other sites More sharing options...
lynnm Posted January 11, 2003 Share Posted January 11, 2003 Nice call WFM ! I know that I have acknowledged your TS skills before but if you ever get sick of making a decent living - Remember you would make a damned good computer tech ! Quote Link to comment Share on other sites More sharing options...
lkahn Posted January 12, 2003 Author Share Posted January 12, 2003 Somehow I just can't imagine even finding any forum for, let's say, Watt Puppies. And then, even if there was, would there be knowledgeable people around who give serious answers that don't involve spending thousands on some scanning-tunnelling-orbital-shifting paperweight made of the same material as the floors in the entrance hall of Versailles palace. The answer to my question, as you guys immediately suspected, was.......dust. That, and a lost connection between the front and back parts of one input. Funny how things like that make a difference. Now I can set about figuring out how BK's play music. Thanks again for helping me out. L Kahn. Quote Link to comment Share on other sites More sharing options...
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