... amplifier speaker 2.4.1ch circuit design 3.USB,SD,FM function 4.OEM service 5.VFD display New design 4.1 amplifier speaker ... 1.Hot 4.1 speaker , solemn and delicate overlook, both ... remote control.3. 5.25" composite cone speaker adopted in bass part, enable low-mid section ... 40HQ1632 sets Hot 4.1 amplifier speaker with USB/SD/FM function and VFD display ...