I'm wondering if these outputs sound right when calibrating the input sensitivity on a JL 500/1v2.

Components I have:
1.) Alpine CDA-9813
2.) JL 500/1v2
3.) JL 10W6v2

I see that the chart says while playing a pure 50hz tone at -0db for a 2 ohm load (10W6v2-4) the output should be 31.6 volts with the volume **** at 75% of max (I had it at volume #27).

I set the voltage to 31.6. The thing that doesn't seem right is when i put the volume down one notch to 26, the voltage dropped to 21. Does this sound right or is there something fishy going on?

 

nope its correct. every head unit has an output voltage. this can range from 1v to 8v of non-clipped signal. It can be a lot higher with a clipped signal but this also add distortion and possible speaker damage as well.

Alpine deck typically put out max non-clipped signal from 22-24 on the volume. you could set you deck to 23 as the max and adjust the amp accordingly.

 

your Gain is a Multiplier of the input signal. I didn't look up your head unit, but most alpine's have a 4v pre-out. The Analog Pot on the amp just amplifies that input signal via the amplifer. As far as your actual output in Vout, i don't know what the figure would be, but as long as your signal is not clipping your fine.

 

Sounds correct to me. 94