I think people blame crackling sounds on drivers because reinstalling drivers is an easy fix. I've only ever encountered driver-induced speaker noise once.
The vast majority of times I've encountered crackling, it's because one of the wires carrying the signal to the speaker is loose. The crackling is due to the intermittent contact of the wire, causing the speaker to try to generate square waves (suddenly goes from no signal, to a signal, back to no signal). If the crackling increases when you move or shake the laptop, it's almost definitely a loose wire.
If you're handy with a soldering iron, in most cases this is an easy fix. Find the offending wire, and solder it back into place (usually you don't even need solder - just heat the existing solder on the speaker until it melts, then stick the wire in). If the bad solder joint is on the motherboard, that's a little trickier because the motherboard solder joints tend to be a lot smaller. But the same procedure usually works there. Rarely, the break is in the middle of the wire, which may necessitate replacing it.