Yamaha NS-SW700: ADVANCED YAMAHA ACTIVE SERVO TECHNOLOGY II

ADVANCED YAMAHA ACTIVE SERVO TECHNOLOGY II

In 1988, Yamaha brought to the marketplace speaker

Yamaha’s newly developed Advanced YST II adds many

systems utilizing YST (Yamaha Active Servo Technology)

refinements to Yamaha Active Servo Technology,

to give powerful, high quality bass reproduction. This

allowing better control of the forces driving the amplifier

technique uses a direct connection between the amplifier

and speaker. From the amplifier’s point of view, the

and speaker, allowing accurate signal transmission and

speaker impedance changes depending on the sound

precise speaker control.

frequency. Yamaha developed a new circuit design

combining negative-impedance and constant-current

drives, which provides a more stable performance and

As this technology uses speaker units controlled by the

clear bass reproduction, without any murkiness.

negative impedance drive of the amplifier and resonance

generated between the speaker cabinet volume and port, it

creates more resonant energy (the “air woofer” concept)

than the standard bass reflex method. This allows for bass

reproduction from much smaller cabinets than was

previously possible.

Cabinet

Air woofer

(Helmholtz resonator)

High-amplitude

Port

bass sound

Advanced impedance

Converter

Active

Servo

Signals

Processing

Amplifier

Signals of low amplitude

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