[beat]

hey all,
does anyone know how to tell if you are producing one watt from your amp? I would like to evaluate speaker efficiency...I just picked up a nice spl meter...as well as a tube tester>> Woohooo! with all this new lab stuff, I'm starting to feel like a real sciematician

[JohnR]

Because speaker impedance varies so much, what is done in practice is to provide a voltage that represents a nominal 1 watt into an resistive 8 ohm load, i.e. 2.83 V RMS.

An SPL meter won't give you an accurate result because of room reflections...