[atledreier]

My definition of transparent is how well you are able to locate your speakers with your ears. In my system sound can be coming from the position of one of my speakers, but still not seem to come from the speaker box itself. To me, that's transparency.

Soundstage to me is the system's ability to convey the size and properties of the recording venue. A recording from a concert hall will sound big and spacious, a recording from a small club will sound smaller and with all the ambiance intact. Studio recordings often lack an overall soundstage, but if the engineer have some skill it can be faked pretty good.

Speed to me is more about agility, really. A system that can keep up with fast changes in musical pace, and that have good timing and are able to go silent quickly sound fast to me. Also, many seem to think that mid-bass punch signifies a fast system, and a system with good extention is slower. Basically what Wayne said.