CLAMPING MY AMP?!?!?! Weird readings?!?!

[XORstatus 10+ year member]

I am apparently doing something wrong, I'm making this assumption due to the weird readings that I'm getting from my clamp and multimeter.

I clampped first the hot speaker terminal of my amp, then I tried the negative.

The highest amp reading that I got was about 20, at full tilt on an AUDIOPIPE 1.5k.

I sylimitaneiously multi'ed the voltage of the speaker terminals, which was ridiculously misleading. I got readings of 2 to 5 volts but they were jumping all over the place.

There is apparently something I'm forgetting or am just negligent about.

Pointers?

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[ahole-ic]

Play a tone. NOT MUSIC. VAC on the multimeter. AC current on the clamp meter and place it around the positive lead. It really shouldn't matter on that but just do that for consistency's sake.

 

[TheUnderFighter 10+ year member]

^ this. haha. I made the mistake forgetting to put my test tone CD in a few weeks ago, and was like, WTF is wrong with my multimeter??? ohh, yea...

 

[akheathen Premium Member]

oh, yah, you need to have it on ac between speaker wires. if you don't clamp with an amp meter, then you are not getting accurate, box rise will change the impedance significantly. it is possible to get a reading off music with the correct peak/hold setting on the meter, but it will not be that close to realistic. also, for a true rms, you need to see the wave on an o-scope to see where distortion starts.