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how to measure the impedance during a burp? Also, why does the imp. change when the amp is turned on? I have dual 2 ohm subs, but when the amps are on some will read like 5 ohms and some wont read anything Thanks for the replies!!!
-------------------- Scottie Johnson Sound Pressure Technologies
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When the amps are turned on you will be reading both the resistance of the sub and some internall resistance inside the amp. I believe this is where you are getting the change in resistance.
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I was sure I posted this yesterday, but I guess better late then never
You can't measure resistance on a live circuit with a multimeter. A DMM measures resistance by putting a constant current through the device tested and measuring the voltage created. With the amp on there will be current flowing through the circuit from the DMM and the amp and the DMM will be very confused. The only way to measure impedance while the subs are playing is to measure the current and voltage at the same time and doing the math. You can use a clamp on current meter to measure the current, while using a DMM to measure the voltage. Another option is to get a current shunt, a low value resistor that can handle the high current, and measure the voltage across that to figure out the current, and again measure the voltage across the subs with the DMM.
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