You mentioned the magic word. (JBL). Your price range does put some restrictions on you though. For a starter 5:1 setup, I’d look at the JBL Studio L series or the Venue series.
You can get 4x Studio L830 for about $600. Add a LC1 center for about $400, and a L8400P sub for about $500. There goes your $1500, but you will not be disappointed. The L830 is a bit small for the main L-R, but you could upgrade to larger mains later, the L890 is very popular, then move the L830s to 7:1 surround duty. Any of these speakers will knock your socks off.
The Venue series is more of an entry-level line, but does contain some good units. I’d look at the Stadiums for mains, the Arena for surrounds, Sub12 for sub and Voice for center. These will not have near the punch that the Studio L series does, but will save you some money.
A lot depends on what you’re using to drive the speakers.