Thank All of you. Maybe I understand a little better now. A SPL meter plugs into the unit, not a Mic??? AND all g68's have room correction notwithstanding how old they are?? just making double sure. cause I really wannna buy one tonight and don't want to make a dumb decision. I appreciate the help

Halej

#1 G68XXV, Bryston 14B SSt Pro, B&K 200.3, Classe'70, Canton Vento 809, 805, 802, Oppo93, Shiit Bifrost D/A, Mac Mini, Explorer, Behringer 2496, Onix Rocket UFW-10 Subs, PS3
#2 568.2MM, 562 V2, 598, (Extra stuff)