Hello guys,
I have just purchased that Logitech Z5500 sound system. I am trying it just now and I must say it sounds quite well. But I think that the producer of this equipment has invented a perpetum mobile. In user manual they say it has 500 Wats(RMS) of output power. But, next to the el. input socket on the rear panel of subwoofer there is written 230Volt / 1.5Amper and there is 2A fuse (european model). So 230x1.5=345 Wats of input power. So even if we admit 100percent of efficiency (common power amplifiers has about 60 percent), it must be a Perpetum Mobile :-)
Jarda