SemiLive,

The price difference is explained in part by the fact that Carvins are made in the USA, whereas Behringers are made in China, so you can find solace in the fact that the extra money you paid has kept some American gainfully employed

The other difference between Logitechs and any "pro" gear, is that the "pro" manufacturers produce perhaps hundreds of units, whereas Logitech has tens or hundreds of thousands of the speaker sets made (probaby somewhere in Indonesia). So the economies of scale come into play bigtime (you could pay 2-3 times as much if these were made one at a time, like the Carvins).

And of course, with the Logitechs you need to use an external mixer.