Set different volume levels for each app in ALSA (fuck pulseaudio) + you can record sound from soundcard

.asoundrc

#
# Defaults
#
# Step 1: Put this file to $HOME
# Step 2: Configure your application http://www.zimagez.com/zimage/2017-03-1121-55-45.php
# Have fun! http://www.zimagez.com/zimage/2017-03-1121-56-31.php

#
# Defaults
#

pcm.dmixer {
		type dmix
		ipc_key 1024
	slave {
		pcm "hw:0,0"
		period_time 0
		period_size 1024
		buffer_size 4096
		rate 48000
	}
	bindings {
		0 0
		1 1
	}
}

# global volume
pcm.master {
	type softvol
	slave {
		pcm "dmixer"
	}
	control {
		name "Master"
		card 0
	}
}

pcm.!default {
	type plug
	slave.pcm {
		@func getenv
		vars [ ALSA_PCM ]
		default "out"
	}
}

#
# Loopback support (modprobe snd-loop)
#

# to record and hear the output we need this
pcm.out {
    type plug
    slave.pcm "multi"
    route_policy "duplicate"
}

pcm.multi {
        type multi

        slaves.a.pcm "loopback"
        slaves.a.channels 2
        slaves.b.pcm "master"
        slaves.b.channels 2

        bindings.0.slave a
        bindings.0.channel 0
        bindings.1.slave a
        bindings.1.channel 1
        bindings.2.slave b
        bindings.2.channel 0
        bindings.3.slave b
        bindings.3.channel 1
}

# to change loopback volume
pcm.loopback {
	type softvol
	slave {
		pcm "hw:Loopback" 
	}
	control {
		name "Loopback"
		card 0
	}
}

#
# Applications
#

pcm.firefox {
	type softvol
	slave {
		pcm "out" 
	}
	control {
		name "Firefox Master"
		card 0
	}
}