SOT: how do I test dubious speakers?

[brett]

Hi
I've got a pair of Celestion Heritage 12s in a cheap Marshall JTM60 I just bought.  But I'm worried that one or both are damaged.  How can I give them a check-up? 

Measure the voice coil resistance?  Anything else?
thanks

[R.G.]

DON'T push the cones in listening for voice coil rub. That's a good way to cause it.

Feed them a low level pure sine wave from a generator and listen for distortion at gradually increasing levels. Do that with a hifi amp, preferably. If you get up to significantly loud levels and don't get a lot of distortion, they're good.

After that, play them. They'll have early cone breakup, so be aware of that, but that's a "feature" for many Celestions.

[brett]

Thanks RG.