WARNING- This does deal with some minor electricity, I seriously doubt you could be injured but, regardless, YOU are responsible for YOUR OWN actions.
Step 1: Materials
-Old speaker, preferably one with a tweeter
-Computer fan, doesn't need to be lit but I had one and it looks cooler
-Toggle switch (optional)
-Maybe some wire
-Activated carbon (buy at a pet store in the fish section)
-12 Volt DC power pack
-Dremel, X-ACTO knife, or similar cutting tool.
-Sabre Saw (optional)