If you are thinking 4 M770 why would you not go 4 Bullets? IF you are concerned about the sound projection at wakeboarding lengths behind the boat the Bullets win hands down. If don't care about hearing the tunes at wakeboarding speeds go with the JL's. The HLCD's are not that harsh at the closer length of surfing if you have a Wetsounds 420 SQ . You can adjust the mids lows and highs to take a bit of the sharpness out of the HLCD speaker at the shorter distances created by surfing. However no matter how hard you try you can't drive those JL's to wakeboarding ranges.
If you plan on listening to tunes at all while wakeboarding that hands down Bullets. Even if its only 2.
2000 X-Star, 3000lbs ballast, LTR 330, Acme 1235 14.5X14.25prop.