I am trying to measure the maximum power of the board and the power of the speakers with the oscilloscope. Here is what I mean to do:

First, I get the maximum power of the speakers by using the source of 1000Hz sine wave. Next, I put the 2 probes of the oscilloscope and stuck them to 2 leads of the speaker. Then I use VAC view to see the max voltage. Then I can determine the power by using the formula P =U^2/R.

For the power of the board, I also have a DC power supplier. I still use the input source as same as above. Then, I can get the board power by using the formula P =UI.

Is this right, I hope you guys can help me.

Thank you so much!