default_gain.conf modding? topic

Hello there

I would be glad if someone could give a short tutorial about how to change volume gains in default_gain.conf. For example: how to boost microphone sensitivity. My problem is: i dont understand all commands, so I dont know what to change. can someone explain, which command is useful for what? Here are the command names (its form input voice):

Modifier "Voice" {
SupportedDevice {
"Headset In"
}
Enable {
{ "AIF1ADC1 HPF Mode", 1 },
{ "AIF1ADC1 HPF Switch", 1 },
{ "IN1L Volume", 18 },
{ "MIXINL IN1L Volume", 0 },
{ "AIF1ADC1 Volume", 96 },
}
Disable {
{ "AIF1ADC1 HPF Mode", 0 },
{ "AIF1ADC1 HPF Switch", 0 },
{ "IN1L Volume", 11 },
{ "MIXINL IN1L Volume", 0 },
{ "AIF1ADC1 Volume", 96 },

Let me tell you what I know so far:
- AIF1ADC1 HPF Mode is for disabling or enabling high pass filter. But what is high pass filter?
- AIF1ADC1 HPF Switch is the filter for low or high frequence vioce. You can set the focus on low or high frequences.
- IN1L Volume is probable the mic sensitivity...? I dont know.

My questions:
- Whats the difference between enable and disable options?
- What are AIF1ADC1 Volume, MIXINL IN1L Volume and IN1L Volume for?
- If my previous knowledge right so far, what exactly are AIF1ADC1 HPF Mode and AIF1ADC1 HPF Switch good for?

Yeah I looked up the words and explained above, what I know. BUt to be honest, Im still confused. So lets say I dont know anything bout the commands above.