KLH 12's crossover?

[Guest]

Hello.

I have just gotten a pair of KLH 12's. With the crossovers, both woofers work although 1 only works right depending on the switch position. The midrange and the tweeters are bairly audible.I have tested all drivers without the crossovers and they work fine.I have cleaned the switches as suggested in another posting.

Does anyone know the value of the capacitors. I'm sure I could replace them if I knew what ones to get.

If anyone has replaced the capacitors I would sure like to hear about your results.

Any other information or suggestions would be appreciated.

[mrdb]

I just rebuilt a pair of KLH Fives. Your crossover is probably similar to mine in the upper two frequency ranges. I found that the non-polar electrolytic caps are likely to fail. The same dual-section cap was open in both of my units. This prevented tweeter output. You could have something similar wrong with your Twelves. The cap values are marked on the parts and will say something like "25 UF 50 VNP", which is a 25 microfarad, 50 volt non-polar part. I would replace all of the caps with your favorite brand of polypropylene capacitors. A non-functioning woofer path will require some circuit tracing. You said that the woofer driver is OK so there could be an open connection on either lead. Don't overlook the ground path: My Fives returned all driver grounds through the crossover chassis and some grounds were oxidized where the terminal strips were riveted to the chassis. The poly caps will be physically larger than the electrolytics, so you may need to secure them differently. I used hot-melt glue. I was worried that the cap cases would melt but they seem OK.

My Five schematic is due to be placed in the KLH section soon. The existing one on the site does not agree with my physical crossovers.

Bob

[administrator]

I should be able to get to the KLH updates today .. thanks again for sending that information over!

Mark

[administrator]

Thanks to Bob, aka mrdb, we have both a picture and schematic online of his KLH 5 crossover. Bob also sent over a MS Word document detailing his project which is an interesting read!

Until my domain (arsenal.net) points at the new webserver, you can get to it by using this link:

http://168.143.114.212/speakers/speakers.htm

Mark

[Guest]

Bob .Thanks for your reply.

Have read about your rebuild and viewed the picture on your model 5's. I am going to rebuild the model 12 crossovers.I will replace all the caps and resistors as recommended by Stephen from Layne audio.

The model 12 crossovers are external. Everything is mounted on a piece of plywood so I don't think there is a ground problem. There are 4 switches on the crossover (contour control)300-800/800-2500/2500-7000/ and 7000-20000. I'm also going to try to find some of that adhesive to reseal the surrounds.

Gary.