I am trying to play Super Smash Bros Brawl on the Dolphin Emulator but the speed of the game is incredibly slow.
What can I do to prevent this problem, so that I get faster character animations and movement?
Here are a few things you can do, to improve the speed on Dolphin: (Source: Dolphin Wiki Performance Guide)
The bold options may greatly improve performance. Keep in mind, though, that some games require some options to be enabled/disabled, even if this would reduce performance. For example: Skip EFB Access from CPU is an option that greatly reduces emulation speed, but is needed for Super Mario Galaxy.
If messing around with these options do not help achieving a fast enough speed, you may always try this:
Emulation -> Frame Skipping increase the value
This improves the emulation speed, but also results in laggy animations (as a result of skipping frames). The higher the value, the faster the emulation and the laggier the animations will be.
Setting it to 1 or 2 is usually good enough.
If all else fail: Get a faster CPU.
According to the Devs, Dolphin does not benefit from more than 2 cores. Also: More GHz == better (Intel and AMD CPUs do not perform the same at the same clock speed, though, so you might want to keep that in mind before purchase).