Whenever I try to do this in emplode it takes at least 5 minutes to download one average size track. This is over ethernet so surely it should only take a few seconds
Correct, it shouldn't take that long per song. I would check your network connections, wiring, and driver configurations. For example, do you have a piece of firewall software running that filters all incoming data? Does your hub show tons of collisions during the download?
Another reason I've seen for slow ethernet transfers is when a gamer has run some kind of "optimization" utility that's supposed to speed up your ping times when using a dial-up modem to play internet games. These often change things like the MaxMTU variable and the packet size, which are supposed to speed things up for modems. The problem is that these slow down ethernet sometimes.