You sure about that model number? I used to have a pair of the ARC 30 bookshelf speakers, and the manual I have only lists the ARC10, ARC30, ARC100 and ARC Center. (The manual is online in PDF format at http://manuals.harman.com/jbl/hom/Owner's%20Manual/ARC30%20om.pdf)
The ARC100 sounds like what you are talking about, a 10" 3 way.