crossover vs tweeter failure

[skykomish]

hi all

I am very new to this forum and speaker repair, came by a pair of thiel cs 3's cheaply, but found out the dynaudio d28 tweeters aren't playing. The speakers were supposed to have belonged to a DJ before, so there is a good chance they are blown. But with new ones costing 200 each, I have decided to try to repair them or replace them with another set of tweeters. I would appreciate any advice on how to find out if the tweeters are blown or if the crossovers are messed up, also what would be a good replacemnt, thanks

[Dave Bullet]

To see if the tweeter is goosed, use an ohmmeter across the tweeter terminals and see if there is any resistance - none indicates an open circuit (ie. break in the voice coil / burnt out voice coil).

[Cal Weldon]

Originally posted by Dave Bullet
none indicates an open circuit

None indicates a short.

[skykomish]

Thanks for the tip, should the speakers be playing when I check with the ohmmeter?

[Geek]

Originally posted by skykomish
...should the speakers be playing when I check with the ohmmeter?

Nope!

Not playing and unhooked from their wires. The crossover (and amp) will mess up the meter reading.

Cheers!

[discreteouts]

No, they should not be playing or even hooked to the crossover while testing for ohms. Even if you conclude that the tweeters are in fact blown, that won't rule out the crossovers, as the cause of their failure. As far as replacement tweeters, you might want to look into having them repaired or their voice coils replaced. You might be able to do it yourself if the coils are available as replacements. This can be a fairly easy task on some types of tweeters, but very difficult on others. In any event, make certain that the crossovers are healthy, otherwise you will just be replacing the tweeters again. Don't attempt testing the tweeters by connecting them directly to an amp's output, damage to the tweeters and/or source could result. You could, however, quasi-test the crossovers with some cheapo "sacrificial" $1-$2 tweeters(or a full range driver), but there are certainly better, more accurate ways. You would need to know what load the xovers are designed to operate at(4-8ohms, etc). Circuit protection(between the xovers and drivers) for the tweeters might have saved their destruction. Good luck. -discreteouts
PS Of course, you could always replace them with some budget units, but it may throw the xovers out of their design specs, at least for the hi pass section.