Yamaha RX-V365 Owner's Manual

Contents

11In 1988, Yamaha brought to the marketplace speakersystems utilizing YST (Yamaha Active Servo Technology)to give powerful, high quality bass reproduction. Thistechnique uses a direct connection between the amplifierand speaker, allowing accurate signal transmission andprecise speaker control.As this technology uses speaker units controlled by thenegative impedance drive of the amplifier and resonancegenerated between the speaker cabinet volume and port, itcreates more resonant energy (the “air woofer” concept)than the standard bass reflex method. This allows for bassreproduction from much smaller cabinets than waspreviously possible.Yamaha’s newly developed Advanced YST II adds manyrefinements to Yamaha Active Servo Technology,allowing better control of the forces driving the amplifierand speaker. From the amplifier’s point of view, thespeaker impedance changes depending on the soundfrequency. Yamaha developed a new circuit designcombining negative-impedance and constant-currentdrives, which provides a more stable performance andclear bass reproduction without any murkiness.ADVANCED YAMAHA ACTIVE SERVO TECHNOLOGY IIHigh-amplitudebass sound PortCabinetAdvanced impedanceConverterActive ServoProcessingAmplifierSignals of low amplitudeAir woofer(Helmholtz resonator)Signals