I am...amazed. Flatly amazed.
These speakers take up so little room on my desk, yet they put out such a big sound. When I first opened the shipping box I was thinking "This box is much too light to be this big.". Then when I got the shipping box open and found the product box inside and it was less than half the size of the shipping box I was stunned. It was almost tiny.
The two speakers are about "normal" size for PC speakers. It's the subwoofer that's the surprising bit. It's approx 6 inches tall and 6 inches deep and 4 inches wide. And it hardly weighs much of anything. But it feels solid. Knocking on the sides you can tell that there's no internal bracing. It sounds hollow. And there's not much to the weight of it, so you know that there's hardly any material to the box itself; meaning that the sides are probably fairly thin. Maybe a quarter inch. But since the power output is only about 20 watts for the sub, then the box doesn't need much mass.
After a 2 week break-in period I sat down with various pieces of music to get an all round feel for the sound these speakers are capable of.
Pushing the speakers at 3/4 volume (sub set at 4/9) with Bad Company's "Electric Land", the bass was solid without a trace of flabbiness. Though the speakers did sound a little strained at the high sound level. Backing off slightly makes all the difference in the world. The fact that the speakers are bi-polar makes them actually disappear in the sound stage. Though, because the speakers only contain "one" driver they can't give you "room filling sound". You can definitely tell that these are small speakers.
Leaving the settings exactly the same, and testing with various genre (except rap and opera, because I can't stand rap or opera) reveals that this initial impression was good across the spectrum.
For $50 these PC speakers are spectacular performers.

(PS: If they don't survive long or fail in some way before a years time, I'll come back and update this review.)

Logitech Speaker System Z323 with Subwoofer I purchased these as a replacement for my old setup. I needed one with a sub that was adjustable and preferred a 2-speaker setup as I was upgrading from an old surround system that I only used the front and subs on, which was getting old and starting to get a short in the cable.

While the audio is pretty good for the price (especially the sub, no disappointment there), the speakers themselves are definitely a noticeable downgrade from what I was using. They definitely sound like the treble is turned way down, giving it a sort of muffled feel like you were using the speakers on a laptop or a monitor. For the price I guess you get what you pay for, but definitely had higher expectations based on the reviews.

Well, my cat chewed all of my 2002 HK speakers that worked great for 15 years.
The Logitech Z323 with Subwoofer perform just as well or in most cases better than the $200 HK I bought 15 years ago.
The cables from the Sub to the L&R speakers are longer than described, which worked out great for the location I have them in.
These are great PC speakers, I was very surprised how well they sound for the money and size.
Buy them, you won't be disappointed!

Tested the Sound range with Ledisi "Stay Together" For R&B bass. Also tested with Disney's Fantasia for Orchestrial Range.. I know HATE my cars factory speakers bc i now tell the difference between BOOM BOOM Bass and Intrumental Bass like upright bass, Bass Guitar, Trombones etc. I love Bass but I LOVE Orchestral and Intrumental music with the FULL Range of sounds. This speaker WILL do your music justice. BOOM BOOM as well as full ranged music. I am a music enthusiast not audiophile/band director.

For $50 Bucks these speakers are a great deal. First time I buy speakers from Logitech. (compatible with my Logitech bluetooth receiver) Thisis how we stream music, it has plenty of power and the subwoofer is great to add that base!. We are going to use these for a small wedding. Also will be buying a wireless microphone. I may update this review when I have that microphone.