Yamaha YST-FSW050: Advanced Yamaha Active Servo Technology II

Advanced Yamaha Active Servo Technology II

In 1998, Yamaha brought to the marketplace

reflex method. This allows for bass reproduction

speaker systems utilizing YST (Yamaha Active

from much smaller cabinets than was previously

Servo Technology) to give powerful, high quality

possible.

bass reproduction. This technique uses a direct

Yamaha’s newly developed Advanced YST II, with

connection between the amplifier and speaker,

many refinements to Yamaha Active Servo

allowing accurate signal transmission and precise

Technology, allows better control of the forces

speaker control.

driving the amplifier and speakers. From the

amplifier’s point of view, the speaker impedance

As this technology uses speaker units controlled by

changes depending on the sound frequency.

the negative impedance drive of the amplifier and

Yamaha developed a new circuit design combining

resonance generated between the speaker cabinet

negative-impedance and constant-current drives,

volume and port, it creates more resonant energy

which provides a more stable performance and

(the “air woofer” concept) than the standard bass

clear bass reproduction with less murkiness.

Cabinet

Air woofer

Signals

High-amplitude

(Helmholtz resonator)

bass sound

Active Servo Processing

Amplifier

Port

Advanced

impedance

Converter

Signals of low

amplitude

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