I have the schematics for my laptop and it has 1uF ceramics on the speaker PA inputs, that's why I linked to that particular one. The other common values I've seen are 2u2 and 4u7, which is a little more expensive but will give more bass --- not that it really matters on a tinny little laptop speaker anyway. At least I'm happy to know that I won't burn out the speakers on my laptop with DC.