As mentioned, DC resistance is about 80% of impedance.
If I ever thought there was a problem in a speaker I was testing for simple resistance, comparing the other identical one would usually confirm whether I had a problem or not.
TOA ZM-104 (plenty on eBay) is a pretty standard unit in the industry.
These are also pretty indispensable in 70v troubleshooting, where a DVM is useless.
On October 29, 2019 at 10:19, Fins said...
It’s in ceiling Def Ted speakers on a C4 amp.
The customer plays them so loud he is deaf Ted?
If they are Def Tech, you could wire two in series to keep the amp from shutting down.
