hmmm same 600 series but different number coding instead of 601 602 etc - 683 684 685 686. same dog different collar? wait n see for the specs, editorial & user reviews
noticed sa subwoofer uses class D amp. ano kaya ito?
"The ASW610XP combines an up-rated 250mm carbon/paper composite driver with a 400-Watt Class D amplifier in, again, a slightly larger enclosure."