I have LCR Polk Audio TL1 speakers that all read zero Ohms but still function correctly...any thoughts?
First of all, are you measuring the speakers at the terminals completed disconnected from everything else including the wiring?
What meter are you using, and what scale setting are you using?
If you are getting a very low DC resistance, the speakers will not be playing normally.
If the speakers have been over driven, then some of the insulation of the VC wire can be fried, shorting VC turns. These speakers can produce sound, and draw very excessive current from the amplifier and destroy it. I have seen this happen.
Lastly because there will always be one or more caps in series with the tweeter, when you measure the impedance of the speakers at it terminals, you are reading the DC resistance of the woofer only, and getting no information about the tweeter.
If your meter is accurate, as measured by testing a resistor of known value, then you should remove the woofers and test them at their terminals. If you then get a very low DC resistance measurement, then those speakers are destroyed.