MB Quart Reference RCE268 6"x8" component speaker system 6"x8" polypropylene woofer with rubber surround 3/4" titanium dome tweeter with composite surround surface-, flush-, or coaxial-mounting options composite ABS/fiberglass basket outboard2-way crossover (4,200 Hz at 12 dB per octave) with 4-level tweeter output adjustment