You probably need a .asoundrc to tell it which microphone to use. Or have and use pulseaudio to make that determination. A lot of devices have multiple soundcards now. Your motherboard, your video card, your webcam, and probably something else USB for a mic that doesn't suck.
$ cat /proc/asound/cards
To determine which cards you have and the index value for the one you want to use. Note that this value can change between reboots. Unless you specifically index your cards.
alsa only for an index value of 1 for ~/.asoundrc:
Code:
defaults.ctl.card 1
defaults.pcm.card 1
defaults.pcm.device 0
If you don't have a .asoundrc, then the default card index that gets used is 0.
pulse audio for ~/.asoundrc:
Code:
pcm.pulse { type pulse }
ctl.pulse { type pulse }
pcm.!default { type pulse }
ctl.!default { type pulse }
And pavucontrol to select your card(s).