tony61 Posted May 12, 2003 Share Posted May 12, 2003 Hey everyone I just got my '78 C'walls and the problem is that the volume of the tweeters is very low. I thought they weren't working at all untill I did the following: I disconnected the leads going to the mids and the woofers. Then turned the low freq. test tone on my Yamaha HTR-5280 on the "wide" setting (somewhere above 250 hz) The sound from the tweeter is inaudible until the volume is turned up to around -22db on the display. They sound good when hooked up normally, but when I put my ear up to the tweeter under mormal listening conditions (around -60db)I can't hear anything. When listening to classical music through my DirecTV with just the tweeters hooked up I have the same result, no sound untill the volume is set to -22db.The sound being output doesn't seem to be distorted or anything, just real low. They have type "B" crossovers, all of the connections are good. In fact everything looks brand spankin' new on the inside. It just seems as though my Heresys had a much higher output when set at the same level. I could put my ear up to their tweeters and hear sound at normal listening levels. What do you think the problem is? Thanks in advance for your learned input Quote Link to comment Share on other sites More sharing options...
JohnA Posted May 12, 2003 Share Posted May 12, 2003 Use a multimeter to check the voice coil resistance of both tweeters after they have been disconnected from the crossover. They should read 6 ohms +/- 0.5. Is the sound from the tweeters distorted? Do you hear any rubbing (ringing) sounds? That could indicate an overheated voice coil that is partially stuck in the magnet gap. You'll need new diaphragms to fix that. If that's O.K., look at the screw terminals for corrosion and clean it off. Last, resolder the connections in the crossover for the tweeter circuit. Test after each step to see it that one worked. The last resort would be to completely rebuild the crossover with new parts. Quote Link to comment Share on other sites More sharing options...
tony61 Posted May 12, 2003 Author Share Posted May 12, 2003 Thanks John, I new I had come to the right place! I'll check resistance A.S.A.P. The sound isn't distorted and there is no ringing to speak of. I'll go ahead now and clean everything up and resolder the circuit. I'll resolder the connection at the tweeter itself as well, just to cover all the bases. If we're looking at a Xover rebuild, do you have any idea what kind of $$$ are we talking? Thanks again for your help. Quote Link to comment Share on other sites More sharing options...
formica Posted May 13, 2003 Share Posted May 13, 2003 If everything checks out, but before you consider a x-over rebuild... i would try flipping the tweeter out of your Cornwalls into the Heresy and vice-versa ... A simple test just to see if the problem follows the tweeter or the x-over. There is always a possibility that the K77 diaphragm has fatigued. Just a thought... Rob Quote Link to comment Share on other sites More sharing options...
Dflip Posted May 13, 2003 Share Posted May 13, 2003 To rebuild the crossovers (Cornwall B network): You need 1 - 2.o uF cap (better quality advised) 1 - 4.0 uF cap (can go less expensive) 1 - 2.4 mH solid wire inductor, 12awg is recommended, but you can use 14 awg Soldering iron and good solder, There is some choice in the type of cap/expense, but here are some options from a company west of Toronto. http://www.partsConneXion.com/catalog/capacitors.html Prices below are in US dollars. Hovland 2.0uF cap $20.55 Auricap 2.0 $8.95 DynamiCap $20.95 Solen PPE $2.00 Solen Polypropylene $ 12.95 Auricap 4.0uF $14.95 Solen PPE $3.35 (this will work fine) Multicap $9.00 Solen 2.4 mHy 12 awg solid wire inductor $36.90 (14 awg for $23.40) Quote Link to comment Share on other sites More sharing options...
oosting Posted May 14, 2003 Share Posted May 14, 2003 I had the same problem with my '78 LaScala's. I replaced the tweeter diaphrams and everything is fine. You can get them from ElectroVoice (or Klipsch). Ed Quote Link to comment Share on other sites More sharing options...
ChrisK Posted May 14, 2003 Share Posted May 14, 2003 Ditto the same problem on my '78 Cornwall's. Replaced the diaphragms with new ones from EV and everything is fine. Good Luck, Chris Quote Link to comment Share on other sites More sharing options...
IndyKlipschFan Posted May 28, 2003 Share Posted May 28, 2003 Chris...if those are your Cornwalls those are BEAUTIFUL!!! BTW for anyone looking to replace the drivers diaphram. This is a MUST link. Might want to print it out just in case it dissapears like I did, http://www3.sympatico.ca/bonaz/Klipsch/K77-diaphram/K77-diaphram.htm Quote Link to comment Share on other sites More sharing options...
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