Summary: I have had these situated underneath/behind my monitor for 2 years now, and they've been doing a fantastic job for my basic audio needs. They are an efficient investment for your mid-range audio needs, but if you're looking for lots of bass and high volume speakers I would look elsewhere.
Pros: Compact size Cost-effective Light
Cons: Not suited for high volume Can lose some lighter musical tones Easy to knock over
Summary: I've been in music forever, both as a musician and home recording. I was amazed at the volume of sound that came from these. And the sound is pretty good. There's bass, but the mids and highs are kind of muffled. But it's way better than using the speakers on my Mac.
Summary: You get what you pay for: in this case, what I feel is the best speakers $20 can buy. Are there better speakers? Of course, but these are great for a guest room or workspace where sound quality isn't incredibly important.
Pros: Cheap, tiny, decent sound
Cons: Ordered two sets, one was defective. Return worked fine. Sound is only decent.
Pros: Small and has the rubber bottom so they don't slide around. Nice and clear sound, but nothing amazing. Pretty much little to no bass, but that is expect. For the price, they are great speakers when you need to listen to something.
Pros: Incredibly cheap and small but produce a quality sound. I use these for my Xbox 360 which connects to my Monitor which doesn't have built in speakers. USB powered from my PC means I don't need to further clutter my room with AC power cords.
Cons: Unable to adjust the height to make it lay flat which would be nice when used with a laptop.