how can i test my amps wattage?

[vn_v6]

hi all, i have a 800w mono block amp, or so it says because it seems to be struggling to power 2 subs, it has 2 25a fuses, but i removed one, and it still works ? lol will that affect its output? and how would i test it?

[StoneX]

14v x 25A = 350W
Amp is only about 80% efficient at turning power into sound, so;
350 x 0.8 = 280W

What amp?

See this

[thedeadwalk]

love the link