Technics SB-AS40 - User Manual

Teclmics
Active subwoofer system
SB-AS40
Operating Instructions
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Speaker lost (4 pcs,: Stereo connection cable
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Summary

Precautions

Safety

Safety instructions for power source, polarization, power cord protection, and nonuse periods.

Installation

Guidance on installing the unit considering environment and placement.

Maintenance

Instructions for cleaning and care of the unit's exterior.

Service

Information on when and how to get the unit serviced by qualified personnel.

Listening Caution

Advice on safe listening levels to prevent hearing damage.

Positioning the Speakers

Attaching Speaker Feet

How to attach speaker feet to prevent movement during loud volumes.

Note When Positioning

Guidelines for optimal placement of the subwoofer near the TV.

Operation

Power Indicator

Explanation of the power indicator lights and standby mode behavior.

Connections

Connecting to Receiver with Subwoofer Terminals

Diagram and instructions for connecting the subwoofer to a receiver with dedicated terminals.

Connecting to Receiver Without Subwoofer Terminals

Diagram and instructions for connecting the subwoofer to a receiver lacking specific subwoofer outputs.

Connecting to Receiver with One Subwoofer Terminal

Guidance on connecting when the receiver has only a single subwoofer terminal.

Connecting Speaker Cables

Instructions on how to properly connect speaker cables to prevent damage.

Protection Circuitry

Troubleshooting Protection Circuitry

Steps to take if the unit's protection circuitry is activated, causing no sound.

Important Notes

Key usage, cleaning, and handling precautions to avoid damage or distortion.

Technical Specifications

Detailed specifications including amplifier, speaker, and general dimensions/weight.

Overview

1. Function Description
2. Usage Features
3. Maintenance Features

The Technics SB-AS40 is an active subwoofer system designed to enhance the audio experience by providing deep, rich bass frequencies. This unit integrates a built-in amplifier, making it a self-contained solution for adding powerful low-end sound to a home audio setup. It is intended to be used in conjunction with a stereo receiver and front speakers, complementing their sound output rather than replacing them.

Function Description

The primary function of the SB-AS40 is to reproduce low-frequency sounds, commonly known as bass, that smaller front speakers might struggle to produce effectively. By handling these lower frequencies, the subwoofer allows the main speakers to focus on mid-range and high-range sounds, resulting in a clearer, more balanced, and impactful overall audio presentation. The "active" designation means it has its own power amplifier, eliminating the need for an external amplifier to drive it.

The subwoofer features a low pass filter, which is crucial for its integration into an existing audio system. This filter allows the user to set a specific frequency cutoff, ensuring that only frequencies below this point are sent to the subwoofer. This prevents the subwoofer from attempting to reproduce higher frequencies that are already handled by the front speakers, avoiding muddy or overlapping sound. The manual provides frequency response graphs to guide users in selecting an appropriate low pass filter setting based on the characteristics of their front speakers.

Another key control is the volume adjustment, which allows users to balance the subwoofer's output with that of their main speakers. This ensures that the bass is neither overwhelming nor too subtle, creating a cohesive soundstage. Like the low pass filter, the manual includes frequency response graphs to assist in setting the volume to a suitable level.

The SB-AS40 also incorporates a phase switching function, offering "NOM" (Normal) and "REV" (Reverse) options. This feature is vital for ensuring that the subwoofer's sound waves are in sync with those of the front speakers. If the subwoofer and front speakers are out of phase, their sound waves can cancel each other out, leading to a perceived lack of bass or a muffled sound. Adjusting the phase helps to achieve optimal acoustic integration and a more natural playback.

The unit is equipped with various input terminals to accommodate different receiver configurations. It can be connected to a receiver with dedicated subwoofer terminals using a stereo connection cable. Alternatively, for receivers without a subwoofer output, the SB-AS40 can be integrated by connecting the speaker output from the receiver to the subwoofer's input terminals, and then connecting the front speakers to the subwoofer's output terminals. This flexibility ensures compatibility with a wide range of audio systems.

An automatic standby feature is included for energy efficiency. If no audio signal is received for approximately 10 minutes after the unit is powered on, the subwoofer will automatically enter standby mode (indicated by a red power indicator). Once a signal is detected again, it will automatically resume normal operation (indicated by a green power indicator).

Usage Features

The SB-AS40 is designed for straightforward setup and operation. The manual emphasizes the importance of proper placement and connection to achieve the best sound quality and ensure safety.

• Placement: The subwoofer should be positioned on a flat, level surface, ideally on its longer side as shown in the illustrations, to ensure stability and optimal sound dispersion. It should be placed at a reasonable distance from the TV and other magnetic field-generating devices to prevent interference. Adequate ventilation is crucial, with a recommended 10 cm (4") clearance from the rear of the unit to prevent overheating. The manual advises against placing heavy objects on top of the unit.
• Speaker Feet: The accessory speaker feet are provided to prevent the subwoofer from moving due to vibrations, especially when playing at loud volumes. These feet are attached to the bottom of the unit, and the manual suggests laying the subwoofer on a soft cloth during attachment to prevent damage.
• Connections: Clear instructions are provided for connecting the subwoofer to a receiver, both with and without dedicated subwoofer output terminals. The importance of connecting positive (+) wires to positive (+) terminals and negative (-) wires to negative (-) terminals is highlighted to prevent damage to the circuitry. Users are also reminded to switch off the power to both the subwoofer and the receiver before making any connections.
• Sound Adjustment: The low pass filter, volume, and phase controls allow for fine-tuning the subwoofer's output to match the acoustic characteristics of the room and the front speakers. Users are encouraged to experiment with these settings while listening to music to achieve a balanced and natural sound. The provided frequency response graphs serve as a visual aid for understanding the effect of different settings.
• Safety Precautions: The manual outlines several safety precautions, including ensuring the unit is connected to the correct power source, proper polarization of the power plug, and protecting the power cord from damage. It also advises against using the unit near water or heat sources and in environments with excessive smoke, dust, or vibration.

Maintenance Features

Maintaining the SB-AS40 is simple and primarily involves routine cleaning and adherence to safety guidelines.

• Cleaning: The cabinet, panel, and controls can be cleaned with a soft cloth lightly moistened with a mild detergent solution. The manual specifically warns against using abrasive pads, scouring powder, or solvents like alcohol or benzine, as these can damage the finish.
• Protection Circuitry: The unit incorporates protection circuitry designed to prevent damage in case of issues like short-circuited speaker wires or using speakers with an impedance lower than recommended. If the protection circuitry activates (e.g., no sound or sound stops), the user is instructed to turn off the power, identify and correct the cause of the problem, and then turn the power back on. This self-protection mechanism helps prolong the life of the unit.
• Nonuse Periods: For extended periods of nonuse, it is recommended to turn off the power and unplug the unit from the household AC outlet to prevent potential issues and save energy.
• Professional Servicing: The manual clearly states that users should not attempt to service the unit beyond what is described in the operating instructions. All other servicing should be referred to qualified service personnel. This ensures that any complex repairs are handled safely and correctly, preserving the unit's functionality and warranty. Contact information for authorized service centers is provided for U.S.A. customers.
• Diaphragm Care: Users are advised not to touch the speaker diaphragms, as this can cause distortion in the sound.

Overall, the Technics SB-AS40 is designed to be a user-friendly and effective addition to any home audio system, providing enhanced bass performance with built-in amplification and essential controls for optimal integration.

Technics SB-AS40 Specifications

General

Brand	Technics
Model	SB-AS40
Category	Subwoofer
Language	English