PhonoPhi
Headphoneus Supremus
ZS10, as the number states, have 10 drivers: 4 BAs + DD per side.I know it's probably been mentioned already, but the KZ ZS10 Pro ($40-$50) are a stellar set of IEMs for their price. Reviews typically give them very high marks, and even stacked up against midrange IEMs that I have they are a solid budget contender (in my experience). For bassheads, and anyone searching for a wider soundstage, plus they are quite compact for a 5BA + 1DD build.
Are you sure that you are not talking about the newest ZSX, which are 5 +1, and are really great (I am currently enjoying music with them).
ZS10 pro are nice, but more V-shape and are a bit less universal and capable.