This has come up before so to clear things up:

SPLIT - parties and radio show run by Ben and Chris Finke www.splitmusic.net

RETROVERT - parties run by Ben Sims and his girlfriend Sunny
www.retroverts.com

FLUX - parties and label run by Chris Finke and Andi Hawes
www.fluxrecordings.com

SPLIT is a combination of the RETROVERT and FLUX