# Should I rebuild my Cantons?



## gottavtr (Oct 24, 2011)

I have a pair of beautiful old Canton Karat 960's that I have loved for years. They sound very clean and natural. Problem is they are starting to have problems. One of them has started to pop quite a bit and the midrange output has dropped out. I opened it up yesterday and the midrange is showing about .4 ohms (still connected to the crossover.) There is also a cap that exploded and an inductor that looks to have gotten very warm. Money is pretty tight so I want to consider all options.

Should I rebuild the crossover? I assume I could find the values on the individual items and solder them on. While I am in there should I replace any other pieces? Should I redo the other speaker's crossover? Of course I need to source another midrange unless the resistance looks better once I disconnect it.

With as much as I love these speakers I love building stuff and would like more output. I completely buy into the idea of huge headroom and some day want to build some new bi-amped speakers. Maybe now is the time to start that project. Don't get me wrong, I will not toss the Cantons in the trash. They will be fixed one day.

Zach


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## mechman (Feb 8, 2007)

I moved this tot he DIY Speaker forum. You'll get more attention here than in the DIY Repair forum.


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## fbov (Aug 28, 2008)

I would start by inspecting both speakers for driver issues first. disconnect and verify they don't rub, and have a finite resistance. Refoaming a bad surround is an option, but I wouldn't recone. Next is rebuilding the XOs, replacing all caps and any resistors or inductors that looked brown. Caps and resistors are cheap (unless you want to pay $$$) and resistance tells you if you hurt a coil. Do the same to both sides. 

Then listen to see if the magic returns... which it will if the drivers are good and you rebuild the XO... until you build something newer as "newer always sounds better" especially if it's DIY!

HAve fun,
Frank


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## fusseli (May 1, 2007)

I agree, if the drivers are still in working order you should be able to fully "restore" them by repairing the crossovers. I'd replace all of the caps in both crossovers, if one exploded that tells me that they are electrolytic and they are probably at end of life. Unless your inductors physically burned I bet they are fine, same with the resistors. The resistors will be easier to identify values for and are really cheap to replace, so why not. Driver replacement could have mixed results if you can't find an exact replacement so hopefully that's not necessary. It would be a good idea to rule out drivers before starting any crossover work, though.

Just be careful as you go such that you are able to verify the crossover is still correct, needless to say you don't want to make or break a non-original connection. Do one side all at once and use the other speaker for reference, just like doing brake or suspension work on a car


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## gottavtr (Oct 24, 2011)

Thanks for the help. The effected midrange driver shows one ohm. I would assume that is a problem. I have reached out to a couple people on EBay that are selling a lot of Canton drivers. I will send Canton USA an email as well. I will start checking the crossovers. To check the resisters they have to be dismounted from the board so they are no longer soldered correct? 
When these were going bad I would hear a load pop from the speaker and the Marantz receiver would go into protection. That happened a handfull of times over a year or so. Was that the crossover shorting or do you think it was the Marantz messing up and sending a large signal to the speaker which blew the cap. 
Zach


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## fusseli (May 1, 2007)

Yikes. I'd guess that a driver or crossover component was failing as a short circuit, causing your poor Marantz to go into protection mode. The 1 ohm measured midrange is indeed a likely culprit.


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## fbov (Aug 28, 2008)

First off, a woofer or full range driver with a 1 ohm DCR is suspect, but not so a midrange, as it's not intended for direct amplifier connection. I expect that with the intended high-pass filter, impedence is just fine at all frequencies. I suggest some low power testing, sans filter, so keep the power low, to hear if there are any response anomalies. If it sounds like a properly functioning driver, use it!

The only resistors one might check are the discolored ones, and I'd just replace anyway. If it shows no signs of overheating, it's likely good, but resistors are cheap. 

Finally, my money's on the crossover shorting, not a bad driver. A loud pop would be the cap blowing through it's electrolyte, shorting the amp and causing you angst. I'm just surprised it occured more than once! And since I haven't seen it, use at least a metalized polypropylene cap; avoid electrolytics, nonpolar or otherwise, unless you need a really big value (they're cheap)

HAve fun,
Frank


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