^^^I have my L & R 703's sitting on top of my dual Subs. I put 6" stands under the subs to reduce "floor effect" and it turned out to be just the right height for the front pair. Perhaps it's better to spend the money on a second sub than stands, if you don't already have a second sub. The LSiM 703's are good down to mid-bass and having my subs just underneath seemed like a good idea.
Samsung UN75HU8550FXZA, SEK 3500 OCB in den, Sony XBR79X900B in LR, JVC RS600, Grandview 120" 1.3g curved screen in Batcave Mancave
Polk LSiM703 fronts, RTi-12 rears, LsiC and LSiM 706 centers, Monitor 40 Heights, Monitor 60 FW, ED A6t sides, Oppo 203
Two Emotiva XPA-5's for the Beds and TC, BasX-7 for the tops, Marantz AV7702MKII in Mancave until consumer-grade 13+ ch Pre-pro is available.