I thought the gain setting was to get the right match for the signal from your source stereo; to your amplifier?? Also, I've heard regularly that the gain knob is not a volume knob, If the gain isn't set to match the source output, wouldn't that affect the quality of the signal?? Someone help me better understand the previous replies regarding setting the gain. Thanks
The gain is to match WITH the head unit's output in order to achieve the desired amp output. (I need a better analogy, but you're not trying to find your twin to marry, you're trying to find your best partner, in order to have the best kid). It's not matching as an equal, but as in a collaboration. A better word is probably a partnership, or a cooperation, but don't expect that to take. It's not matching with, it's matching up with. It's not H = A, it's H x A = S
So lets say your volume knob is 1-26, and your head unit has a 5v preout. 1-26 is adjusting the voltage output. The signal might be sent out as:
1 .2v
2 .4v
3 .6v
etc..
25 5v
26 5.5v (an extra 10% over top for fun).
Before I get to the amp, here is where people get in trouble. They set their gain to the max number on the volume because it's max. This may already be clipping. A cheap head unit might even be clipping before rated voltage. Your rated preout voltage might be below the max volume the knob can go to. That can cause clipping.
The gain is amplifying the voltage, you are adjusting the percentage of how much. This is why people prefer higher voltage preouts, because the gain doesn't need to be turned as high/ You don't need to amplify/ work the amp as hard to get the same output as you do on a 5v preout.
I know it's called a gain, but it might help to think of it as a limiter. You have the output/wattage that you want to send to your speakers. To set your gain, you turn your volume head unit up, (so that it is not a variable) and you set your gain for that wattage (by using ohm's law to convert wattage to AC voltage needed). Now you have the max output you can achieve. Then your volume knob becomes the variable.
Rated power is factored with THD. I have an alpine amp that is rated at 4 x 150w RMS @ 4ohms with .04THD. I've tested that amp to 1% THD and got over 440w RMS. Every amp SHOULD be able to produce more power than what its rating is. If you just turned the gain up, you would clip and blow your speakers.
) without any issue...like stated above, I just had the gain set pretty conservatively...
