Pros: Sound quality, bass, price
Cons: Connecting cables could be shorter
Logitech is well know for the quality of their products and with the Z313 they kept with that!
Being a basic set of 2.1 speakers, one should know what to expect from them. With that in mind they prove to be a really smart purchase, as they are quite cheap for the built in quality offered.
You can see that the design here was thought to be functional, but that does not mean bad looking. The Z313 has a clean desing, pleasant to the eye, and is quite portable. In you do not have that much space for connecting speakers to your device, this proves to be a good choice. The cables are a little bit to long, though. With a bit of organization you will be able to make them disappear, but if they were a bit shorter, things would not get tangled that easily.
The Z313 comes a little control that has the on and off button, the volume control, the green jack to connect to your device, and the 3.5mm headphones plug. That is quite useful and comes in handy, as you do not have to stretch all the way to the speakers themselves.
The subwoofer really makes a huge difference, specially when watching movies (and with bass-oriented songs, of course). The sound is clear and only distorts the sound when in the highest volumes possible. The basic speakers also present good sound quality, making you feel the sounds in a much more vivid way.
In short, these are great 2.1 portable speakers for general use (both music and movies). For their price, they are also a good alternative to the expensive docks out there. being able to easily replace them, as they have better sound when compared with docks in the same price range, although they do not have a built in battery.