Has anyone here used a set of Logitech LS21 2.1 Stereo Speakers? Are they decent speakers? I’m thinking of buying a set ($25.00 eBay). The price seems pretty low for anything of quality, but I’m going by the Logitech name. I play a lot of music through my computer and need good sound quality.
Anyone?? 
I don’t know about Logitech but I have a Harmon/Kardon sub/sat kit that is very good and have just given away a Cambridge sub/sat set and replaced it with an Harmon/Kardon hifi amp and a pair of Jamo speakers. Second hand kit from eBay, only cost £73 including postage and it is leagues better than the ‘computer’ speakers.
Both the HK and the Cambridge kits were £300 each.
If you have a decent hifi try plugging your computer into it and hear the results for yourself.
There’s 338 reviews for the item on Newegg.com, which is where I go to read up on (and buy) all my computer junk.
Comparing Harmon Khardon’s to Logitechs is like comparing a Mercedes with a VW; they’re two different beasties.
I wouldn’t trust the logitech brand for media products. They’re well known for input devices like mice and keyboards but are nothing special for speakers and even their input hardware has gone downhill in the last decade.
I’m not sure I’m best qualified to answer here, so I’ll just give you an anecdote.
I have THESE Logitech speakers. I’m not an audiophile by any means but to me they sound fine. The one complaint I would have would be that sometimes I just can’t get them loud enough, but that’s probably an issue with my computer and the media I play and not so much the speakers’ fault. When the media is loud, the speakers are plenty loud enough! I have to keep the bass down since it’s up on a shelf instead of down on the floor, and I have upstairs neighbors.
Also, like all physical volume knobs seem to do, the volume dial on this will sciz out sometimes, requiring multiple adjustments to get the sound to actually, ya know, work at all. But everything I’ve ever used with a physical (as opposed to digital/electronic, ie: probably a rheostat) volume control has had the same problem, so who knows. I leave it turned up all the way and control the volume through my computer.
If it’s cheap enough and you’re willing to take the risk, go for it. If you’re the kind of guy who claims to be able to tell the difference between Monster stereo cables and the ones you get for $5 at Wal-Mart’s clearance bin, pass 'em by.
As above. You get what you pay for. Don’t kid yourself that $25 gets you anything but junk, no matter who makes it.
Harmon Kardan do make good stuff, I have a set of SoundSticks, and they provide remarkable quality for the money. But if you actually want good sound quality for long term listening, and not just crud sound for games or background music, these are just a starting point. You can spend any amount of money. $25 is less than single night out. One suspects you would be short-changing yourself to spend such a pitiful amount on something you actually want to enjoy long term.
Computer speakers do have a particular issue, because they are usually placed on a desk close to the listening position they need to be designed for both a nearer listening position (often incorrectly termed “near field”) and they may be designed to cope with the presence of the desk surface, which can cause annoying frequency response issues due to a reflection off the desk surface.
There are lots of good speakers around that would suit, and you don’t need to pay big money to get something quite satisfactory. Some of the home studio monitors might be a good place to start. For instance Behringer have reputation for cheap but useful stuff (but not exactly pro quality), you would be hard pressed to beat these speakers (which have an internal amplifier).
Look for a used set of Logitech Z2300 on eBay or your local Craigslist. It’s one of the better computer speaker sets out there and I’ve seen them go pretty cheap on Craigslist.
The Klipsch iFi is the best computer speaker set I’ve heard, although it was sold as an Ipod system. It has reliability issues with the amp so it can be hard to find a working system. And the subwoofer is pretty big, so it might be too big to fit under a desk.
If you have a lot of space, get a good pair of bookshelf speakers and a stereo receiver. You could hide the on the floor or somewhere else out of sight. It could be across the room.
I have what I think are teh ones you are talking about (at least, they look just the same as those in ZipperJJ’s link, and they were in that price range). I have been pretty happy with them. However, I do not use them very much for playing music. The over all sound quality seems fine to me, but you will not be able to get very heavy bass, and, if you like your music very loud, you will be disappointed. The volume is fine for most purposes, but you are not going to blast your socks off with it. You may have some configuration issues too. The sound configuration screen may be frustrating too. It does not seem to recognize the subwoofer when you do a sound test, although the subwoofer does seem to work (though it isn’t very powerful) when you actually use it to play music.