Summary: I was very excited to get these speakers and very disappointed when they came. I love Logitech and prefer them for all of my peripherals, but these were a huge letdown. I received a horrible humming feedback when I first plugged them in. I unplugged the 9-pin connector and reseated it, screwing it ALL the way in. This took care of the hum; however as soon as my foot touched the slack cable, the humming came back.
Summary: I bought these speakers for my girlfriend as a gift because of many good reviews, but I was SO disappointet of the sound when I finally heard them I am amazed how little sound have improved since my first Creative set (Inspire 4.1 4400), a very cheap one indeed, almost same price as this one, and it was back in 2002. The z-523 offers almost only mid-tone sound, which is horrible for both music and games, and the bass is nothing compared to it's giant size.
Summary: Logitech was known to create good sounding computer speakers at an affordable price . The prevoius set I had, the X203 was great. It still sound perfect after all these years. The Z523 however break all the rules we would expect from Logitech. They just does not sound right, and on those rare occasions where one want to turn up the volume, the sub rattle quite badly.
Summary: I bought these speakers about a year ago and just today it decided it wanted to die on me. They were decent speakers but whenever it was turned on too high, it would make crackling noises. Today my left speakers gave out...so I unplugged it and left the right ones in, and now it sounds like there's a thunderstorm inside my room... never purchasing these speakers again.