If you measure the AC voltage and current while still hooked up to your speaker you can find the power your amp is producing into your load accurately.



So we can see that if we multiply voltage by amperes we will get watts.

 

or voltage squared divided by impedence, like i said, many way to figure out the same number

 

Yup, any of those will work, yours is easier without a clamp on ammeter that will read larger amperages, most DMM's are only good for about 10 amps then they blow fuses.

 

there are 2 possible problems I see with defro's method (no dis intended, just kind of thinking outloud, feel free to correct me)

1) unless you have a 'good' dmm like a fluke that shows true rms the meter kinda fudges the number and will only be accurate with a 60hz tone (wich is easily done)

2) it's my understanding that the resistance you read off the speaker terminals is not the same as the impedance the amp will see when music is being played, as I understand it the impedance changes all the time.

so the only true way to measure the output would be with a clamp on ammeter and a volt meter(that reads tru rms or use a 60hz tone). unless of course you have the equiptment to map out the impedance graph

again I've never tried this, just thinking out loud ...flame me as you wish [img]smile.gif[/img]

 

the method i recommended can be done by anyone with even a 29.99$ meter from canadian tire. its very accurate with individual tones only, 36hz, 42hz, the frequency doesnt matter as this test will on;y tell you ac voltage at 1 frequency at a time,the test is accurate as is done with a resistive load, aka hooked up to speakers, but like dwvw said there are many ways to get the same answer

 

yes use the same method to level match the amps, make sure you so this with the woofers hooked up to the amp for testing and remove the wires from the amp to get your initial impedance reading.

 

To level match amps, all you really need to do is play a test tone through it and measure the AC voltage and set the other gain to match.