I need some help tuning my amps with a oscilloscope

[Snuskgamer]

I have an fluke 43B power quality analyser.
And I'm having trouble with reading the rca voltage, I'm getting a output of 0.2 volts and my head unit is supposed to have a rca voltage of 2 volts.

 

[Jimi77]

The rca is suppose to have ~2 vac before clipping but my HU is only producing 0.2 vac clean before clipping.

Edit: there is coming sound out of the sub and speakers I just want to know how much I can tune it before it's clipping

You can also do the same test with a 0db sine wave, say 1khz or 2.5khz sine wave. Turn up the gain or volume, you'll hear the pitch of the sine wave change and that's clipping. When you hear the clipping, turn the gain down 2-3 db. If you have really good ears, you can turn it down just 1db.

 

[Snuskgamer]

You can also do the same test with a 0db sine wave, say 1khz or 2.5khz sine wave. Turn up the gain or volume, you'll hear the pitch of the sine wave change and that's clipping. When you hear the clipping, turn the gain down 2-3 db. If you have really good ears, you can turn it down just 1db.

Yeah but how will i tune my subwoofer?

 

[Jimi77]

Yeah but how will i tune my subwoofer?

Turn the subwoofer output to max. Turn the gain down on the amp to where you're comfortable the the amp isn't clipping. Play a 0db sine wave at say 50-60hz and turn the volume up on the radio until you here the pitch/tone of the sine wave change - it'll get higher, it may take on a more mechanical or harsh sound. That's clipping. Now you've identified where you can hear clipping from the HU pre-amps. Keep your volume 2,3 db below where you can hear clipping and you should be good. You should probably repeat the process a few times so your ears can become accustomed to what a clipped sine wave sounds like. There may be comparison tracks floating around on the internet to help your train your ears.