In this instructable ill show you how see the speaker resistance with Tester.
Needed Materials :
Step 1: Set Tester .
1) Turn On the tester and select the resistance measuring (set on 200 Ω)
2) Take the tester terminals on the speaker terminals and wait the number displayed .
If the resistance number is major then speaker resistance,is good, if instead is minor the speaker it lost resistance (but work however).
You cannot do anything to increase the resistance,only replace the speaker with new one.