Comparing amp power used vs amp power delivered

[mikey210]

Just to preface this: I'm trying to just use a clamp current meter and DMM to calculate power i/o

I'm trying to figure out why my calculations are wrong when measuring my amp's input power vs its output power on my ~1 ohm subs (my subs meter in at 800mohm at DC).

I tested with a 50Hz tone and measured the input voltage at the amp to be 12.6VDC (used DMM) at 45A (used current clamp). At the output of the amp (terminals) the VAC measured was 36.25VAC (RMS) @ 50Hz. Given these measurements... this doesn't add up.

567W (DC input) vs 1314.06 V/A ((36.25*36.25)/1=1314.06)

(i understand that Pf !=1 here but still assuming it's negligible given the massive "calculated" power difference)

Anyone see a flaw in the methodology here?

Thanks

[ckeeler11]

at 50 Hz you are not going to be at 1 ohm. You are chasing your tail since resistance will change as frequency changes so unless you are only playing tones there is no point.

[Kyblack76]