Technics SB-G400 - User Manual

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Summary

Specifications

SB-G400 Specifications

Detailed specifications for the SB-G400 Hi-Fi Speaker System, including type, impedance, input power, and dimensions.

SB-G500 Specifications

Detailed specifications for the SB-G500 Hi-Fi Speaker System, including type, impedance, input power, and dimensions.

Installation and Connection

Installation of Speaker System

Guidance on optimal placement of speaker systems for best sound reproduction and minimizing resonance.

Connecting the Speaker System

Instructions on how to properly connect speaker wires to the system terminals, ensuring correct polarity.

Speaker Protection Circuitry

Operation of Protection Circuitry

Procedure for resetting the speaker protection circuitry and troubleshooting interrupted sound.

Speaker Component Removal

How To Remove Speaker Components

Step-by-step instructions for removing Super Tweeter, Tweeter, Midrange, and Woofer units.

How To Remove Breaker and LED

Procedure for removing and replacing the breaker and LED indicator on the enclosure.

This document is a service manual for the Panasonic Hi-Fi Speaker Systems, specifically the SB-G400 and SB-G500 series, including their K, FE, and XFEE variants. It provides detailed information for servicing, maintenance, and understanding the functionality of these speaker systems.

Function Description

The SB-G400 and SB-G500 are multi-way Hi-Fi speaker systems designed to reproduce a wide range of audio frequencies. They incorporate a speaker-protection circuitry to safeguard the tweeter from damage due to excessive input or abnormal signals. This protection system includes an LED indicator that lights up when the input to the tweeter is cut off, and a reset button to re-engage the input. Both models also feature a level control for continuous adjustment of high-frequency sound, allowing users to tailor the audio output to room acoustics, sound sources, and personal preferences.

The SB-G400 is a 4-way 5-speaker system, while the SB-G500 is a 4-way 6-speaker system, indicating a slightly more complex and potentially more capable audio reproduction for the latter. The "K" variants (SB-G400K, SB-G500K) are noted to have a black finish. The "FE" and "XFEE" variants indicate regional availability, with "FE" models available in the Far East PX only, and "XFEE" models available in European Audio clubs.

Important Technical Specifications

SB-G400

Type: 4-way 5-speaker system
Speakers:
- Woofer: 37 cm (14-1/2"), cone type
- Midrange: 12 cm (4-3/4"), cone type
- Tweeter: 10 cm (4"), cone type
- Super Tweeter: 1.4 cm (5/8"), dome type x 2
Impedance: 8 ohms
Input Power: 200 W
Output Sound Pressure Level: 96 dB/W (1.0 m)
Crossover Frequency: 1,500 Hz, 4,000 Hz, 10,000 Hz
Frequency Range: 25 Hz ~ 25 kHz
Dimensions: 41.8(W) x 66.9(H) x 29.6(D) cm (16-7/16" x 26-5/16" x 11-5/8")
Weight: 19.5 kg (43.0 lbs.)

SB-G500

Type: 4-way 6-speaker system
Speakers:
- Woofer: 41 cm (16-1/8"), cone type
- Midrange: 12 cm (4-3/4"), cone type x 2
- Tweeter: 10 cm (4"), cone type
- Super Tweeter: 1.4 cm (5/8"), dome type x 2
Impedance: 8 ohms
Input Power: 300 W
Output Sound Pressure Level: 99 dB/W (1.0 m)
Crossover Frequency: 1,500 Hz, 4,000 Hz, 10,000 Hz
Frequency Range: 20 Hz ~ 25 kHz
Dimensions: 46.4(W) x 71.0(H) x 29.6(D) cm (18-1/4" x 28" x 11-5/8")
Weight: 21.2 kg (46.7 lbs.)

Both models feature similar crossover frequencies, indicating a consistent approach to frequency division among the drivers. The SB-G500, with its larger woofer, higher input power, and slightly better output sound pressure level, suggests a more robust and potentially louder performance compared to the SB-G400.

Usage Features

Speaker Installation: The manual emphasizes the importance of proper speaker placement for optimal sound reproduction. Speakers should be placed on a firm, level floor, and the distance between the speakers and the listener should be considered. The manual also advises against placing speakers in direct sunlight or near heat sources, and recommends using curtains or sound-absorbing materials to prevent undesirable resonance and sound reflection. For connecting the speakers, the manual provides detailed instructions on stripping wire ends, twisting them, and inserting them into the terminal holes, securing them by turning the knob clockwise.

Power-Handling Capacity: The speakers are designed to handle specific power levels, and exceeding these limits can damage the unit. The power-handling capacity is determined by the amplifier's volume control. The manual warns against increasing the amplifier volume too much, especially if the amplifier's output is so high that the amplifier's volume control is set to an excessively high level. It also notes that higher-frequency input signals are more likely to damage the tweeter.

Speaker-Protection Circuitry: This built-in circuitry protects the tweeter from damage. If excessive input occurs, the input to the tweeter is cut off, and an LED indicator lights up. To reset the protection, users must reduce the amplifier volume, check equipment, wait about 20 seconds, and then push the reset button. The manual strongly advises against increasing the amplifier volume too much after a protection event.

Level Controls: Both models include a level control for continuous adjustment of high frequencies. This allows users to customize the sound based on room acoustics, the sound source, and the characteristics of their phono cartridge and amplifier. The "normal" position is the standard setting for this control.

Maintenance Features

The manual provides comprehensive instructions for disassembling and replacing various components, which is crucial for servicing and repair.

Removing Speakers: Detailed steps are provided for removing each speaker component (Super Tweeter, Tweeter, Midrange, Woofer) for both SB-G400 and SB-G500 models. This typically involves removing setscrews (with specified hexagon wrench sizes) and disconnecting lead wires from the speaker terminals.

Removing Breaker and LED: Instructions are given for removing the breaker and LED, which involves first removing the tweeter and then accessing these components through the tweeter installing hole. Specific wiring diagrams are provided for replacing the breaker and LED, with notes to ensure quick soldering to prevent excessive heat and to avoid short-circuiting the LED ends.

Replacement Parts List: The manual includes extensive replacement parts lists for both SB-G400 and SB-G500 models. These lists detail part numbers, names, and descriptions for:

Speakers: Super Tweeter, Tweeter, Midrange, Woofer
Coils: Choke coils of various mH values
Resistors: Non-flammable, metal oxide resistors with specified wattage and resistance
Capacitors: Electrolytic capacitors of various µF and voltage ratings
Diodes: Including the light-emitting diode (LED)
Attenuator: For sound level adjustment
Breakers: For circuit protection
Cabinet parts: Such as magic tape, gaskets, bushings, panel attenuators, knobs, and spacers
Grille
Net Catch, Plate Terminal, Knob, Ornament, Diffuser, Name Plate
Screws and Washers: Various types of screws and washers for assembly
Accessories: Instruction books, felt speaker units, and speaker cords
Packing Parts: Cartons, pads, and polyethylene bags for shipping and protection

These detailed parts lists are essential for technicians to identify and order the correct components for repair, ensuring the longevity and proper functioning of the speaker systems. The manual also specifies different part numbers for "FE," "XFEE," and "KFEE" variants where applicable, indicating slight differences in components based on regional models.