The Yamaha YST-FSW150/YST-FSW050 is a subwoofer system designed to enhance the low-frequency sound reproduction of your audio setup, providing a more realistic and immersive home theater experience. This subwoofer system incorporates Yamaha's Advanced Active Servo Technology II (Advanced YST II), a proprietary technology developed to deliver powerful, high-quality bass sound from compact cabinets.
Function Description:
The primary function of this subwoofer is to reproduce super-bass frequencies, adding depth and impact to music, movies, and other audio content. It is designed to integrate seamlessly into various audio systems, including multi-channel speaker systems and setups featuring Yamaha Digital Sound Projectors. The Advanced YST II technology utilizes a direct connection between the amplifier and the speaker, enabling accurate signal transmission and precise speaker control. This technique leverages the resonance generated between the speaker cabinet volume and a port (referred to as the "air woofer" concept) to create more resonant energy than traditional bass reflex methods, allowing for robust bass reproduction from smaller enclosures. The newly developed Advanced YST II further refines this by combining negative-impedance and constant-current drives, resulting in more stable performance and clearer bass with reduced murkiness.
The subwoofer features a built-in power amplifier, which generates heat that radiates from the bottom panel. Adequate ventilation space (at least 10 cm on top, 20 cm on the left and right, and 20 cm on the back) is required to prevent overheating and potential damage. The unit is equipped with a POWER button that allows you to turn the subwoofer on or off, or to set it to an OFF/SYSTEM mode for system control. A VOLUME control is provided to adjust the bass level, allowing users to balance the subwoofer's output with their main speakers. An INPUT terminal accepts line-level signals from an AV amplifier, receiver, or TV.
For enhanced system integration, the subwoofer includes a SYSTEM CONNECTOR jack. When connected to a compatible Yamaha component (such as a Digital Sound Projector) using the supplied system control cable, the subwoofer's power mode (ON, OFF/SYSTEM) can be controlled by the power button of the connected component. If the subwoofer's POWER button is set to OFF/SYSTEM, the connected component can turn the subwoofer on or off. If the POWER button is set to ON, the subwoofer will remain on regardless of the connected component's power status.
Usage Features:
The Yamaha YST-FSW150/YST-FSW050 offers flexible placement options. It can be placed horizontally, which is facilitated by its unique and compact design. For the YST-FSW150 model, a supplied stand and screws allow for vertical placement, with non-skid pads to ensure stability. When placing vertically, the bottom side (where the feet are attached) should face a wall. The subwoofer can also be placed in a TV rack or similar furniture.
Before initial use, the subwoofer's volume needs to be pre-adjusted to achieve a balanced sound with the front speakers. This involves setting the VOLUME control to minimum, powering on all other components, then pressing the subwoofer's POWER button to the ON position (or turning on the connected component if using system control). Users should play a source with low-frequency sounds, adjust the amplifier's volume to the desired level, and then gradually increase the subwoofer's volume until it is barely distinguishable from other speakers, aiming for a natural bass sound. For multi-channel home theater systems, setting the VOLUME control to a middle position is recommended.
The magnetically shielded design helps prevent interference with TV picture color, though it is still advisable to maintain some distance from the TV set. The unit is designed to consume a very small quantity of power even when turned off but still connected to an AC outlet.
Maintenance Features:
To ensure optimal performance and longevity, several maintenance and safety guidelines are provided. The unit should be installed in a cool, dry, clean place, away from windows, heat sources, excessive vibration, dust, moisture, and cold. Sources of humming (transformers, motors) should also be avoided. The cabinet should never be opened, and any internal issues should be referred to qualified service personnel.
The subwoofer should not be placed on or under other components in a pile, as its vibrations could cause system failure. Adequate ventilation space around the unit (10 cm top, 20 cm left/right, 20 cm back) is crucial to prevent heat buildup. Covering the unit with items like newspapers or tablecloths is discouraged as it obstructs heat radiation.
Care should be taken to avoid placing fragile objects (glass, china, small metallic items, burning candles, or vessels with water) on the unit, as vibrations could cause them to fall, break, or spill, leading to injury, fire, or damage to the speaker. Foreign objects or liquids should not be allowed to fall into the unit. The YST port on the front should not be used as a handle when moving the unit, nor should fragile objects be placed near it, as air pressure could cause them to fall.
Cleaning the unit should be done with a clean, dry cloth; chemical solvents are not recommended as they may damage the finish. If the unit is not to be used for an extended period (e.g., during a vacation), the AC power plug should be disconnected from the wall outlet. In regions with a VOLTAGE SELECTOR switch (Asia and General models), it must be set to the local main voltage before plugging the unit into the AC supply.
Troubleshooting tips are provided for common issues such as no power, no sound, or low sound level, guiding users to check power connections, cable connections, volume settings, and source material. If these steps do not resolve the problem, users are advised to disconnect the power cable and contact an authorized Yamaha dealer or service center.