Re: Why is PulseAudio the default mixer in Ubuntu?
There's no reason why your laptop speakers would work with Alsa and not with Pulseaudio.
Pulseaudio is just a layer on top of Alsa. Pulseaudio doesn't contain any drivers, it just mixes sounds together and feeds them to Alsa. I suggest that you probably just needed to change a wonky default setting in the Pulseaudio mixer.
The reason why Pulseaudio is default in Ubuntu is simply because it allows for additional features that can't be done, or can't be done easily and reliably, in Alsa. The reason you see so many people saying that they remove Pulseaudio is because it didn't work so well in 2008, and even people whose audio works perfectly well in Pulseaudio today will remove it because that's what they used to have to do.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.