PRODUCT FPD-8CZ FPD-6CZ FPD-5CZ Woofer Size 8' ' 6.5' ' 5.25' ' Voice Coil( inch) 1' ' 1' ' 1' ' Magnet( oz) 15 10 8 Tweeter( inch) 1/ 2 1/ 2 1/ 2 SPL( dB) 90 90 89 Impedance 8ohm 8ohm 8ohm RMS Power/ MAX 20/ 40W 20/ 40W 12/ 25W Freq.Resp( Hz) 30-20K 30-20K 50-20K