JBL JBL400 - User Manual

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Summary

Speaker Placement

Mounting Options

Details various methods for positioning speakers, including on shelves and wall mounting.

Speaker Connections

Connection Tips

Provides essential guidance on correctly connecting speaker wires to the amplifier for optimal sound.

Troubleshooting

Surround Speaker No Sound

Steps to diagnose and resolve issues when surround speakers do not produce audio output.

Center Speaker No Sound

Guidance to fix problems where the center channel speaker fails to deliver sound.

System Shuts Off at Low Volume

Troubleshooting steps for when the audio system unexpectedly powers down as volume increases.

Summary

Speaker Placement

Mounting Options

Details various methods for positioning speakers, including on shelves and wall mounting.

Speaker Connections

Connection Tips

Provides essential guidance on correctly connecting speaker wires to the amplifier for optimal sound.

Troubleshooting

Surround Speaker No Sound

Steps to diagnose and resolve issues when surround speakers do not produce audio output.

Center Speaker No Sound

Guidance to fix problems where the center channel speaker fails to deliver sound.

System Shuts Off at Low Volume

Troubleshooting steps for when the audio system unexpectedly powers down as volume increases.

The JBL400 is a compact speaker system designed for home audio environments, leveraging JBL's extensive experience in sound recording and reproduction spanning over 50 years. This simple setup guide emphasizes ease of installation and connection, ensuring users can quickly integrate the speakers into their existing home theater or stereo systems.

Function Description:

The JBL400 speakers are designed to reproduce audio with clarity and fidelity, suitable for various applications including music listening, movie playback, and general home entertainment. They can be used as part of a stereo setup or integrated into a multi-channel surround sound system as front, center, or surround speakers, depending on the user's receiver/amplifier capabilities and desired audio configuration. The system aims to deliver a balanced sound profile, from detailed high frequencies to robust bass, contributing to an immersive listening experience.

Important Technical Specifications:

High-Frequency Transducer: 1/2" poly dome. This indicates the type and size of the tweeter responsible for reproducing high-pitched sounds, contributing to the clarity and detail of the audio.
Low Frequency (high-polymer laminate): 4-1/2". This specifies the size and material of the woofer, which handles the mid-range and bass frequencies. The "high-polymer laminate" material suggests a design aimed at achieving good rigidity and damping for accurate bass reproduction.
Crossover Frequency: 9.0kHz. This is the frequency at which the audio signal is divided between the high-frequency and low-frequency transducers. A crossover frequency of 9.0kHz means that frequencies below this point are primarily handled by the woofer, and frequencies above it by the tweeter.
Frequency Response (−6dB): 100Hz – 20kHz. This range indicates the frequencies the speaker can reproduce effectively, with a drop of no more than 6 decibels at the extremes. A response starting at 100Hz suggests that while the speakers provide good mid-bass, for very deep bass, a subwoofer might be beneficial in a full home theater setup. The 20kHz upper limit covers the typical range of human hearing.
Sensitivity (1 watt/1 meter): 90dB. This specification measures how efficiently the speaker converts amplifier power into sound. A sensitivity of 90dB means that the speaker will produce 90 decibels of sound pressure level (SPL) when supplied with 1 watt of power at a distance of 1 meter. This indicates a relatively efficient speaker that can achieve good volume levels with moderate amplifier power.
Nominal Impedance: 8 ohms. This is the electrical resistance the speaker presents to the amplifier. An 8-ohm impedance is common and compatible with most home audio receivers and amplifiers.
Recommended Maximum Power Handling*: 50 watts. This is the maximum continuous power the speaker can safely handle from an amplifier. The asterisk clarifies that this rating ensures proper system headroom for occasional peaks and does not recommend sustained operation at these maximum levels. This helps users select an amplifier that won't damage the speakers.
Dimensions (H x W x D): 8-11/16 x 5-7/8 x 5-1/4" (221 x 149 x 133mm). These compact dimensions make the JBL400 suitable for placement in various locations without occupying excessive space.
Weight: 5 lbs/2.3 kg. The relatively light weight contributes to ease of handling and mounting.

Usage Features:

Speaker Placement Options: The manual provides guidance on optimal speaker placement to achieve the best soundstage and imaging. It illustrates placement on shelves, suggesting that the speakers can be positioned on flat surfaces such as bookshelves, entertainment units, or dedicated speaker stands. Additionally, it shows options for wall mounting, indicating flexibility in installation. For wall mounting, the customer is responsible for selecting and using appropriate hardware to ensure safe and secure installation.
Connection Tips: The JBL400 uses standard speaker wire connections. The manual emphasizes the importance of correctly connecting the positive (+) and negative (-) terminals of the speakers to the corresponding terminals on the amplifier. It warns against "out of phase" wiring, which can lead to a thin sound, weak bass, and a poor stereo image, highlighting the critical role of proper polarity for optimal audio performance.
Troubleshooting Guide: The manual includes a comprehensive troubleshooting section to address common issues users might encounter:
- No sound from surround speakers: Advises checking all wire connections for fraying, cuts, or punctures, reviewing the receiver/amplifier's surround-sound features, and ensuring the content being played is recorded in Dolby Surround or that other surround modes are utilized.
- No sound from the center speaker: Recommends verifying the receiver's Center Channel Mode is set to "normal" or "wide" (not "phantom") and checking all connections between the processor/amplifier and the center speaker.
- System plays at low volumes but shuts off when volume is increased: Suggests checking all wire connections for damage and verifying the minimum impedance requirements of the receiver/amplifier, especially if multiple pairs of main speakers are in use.

Maintenance Features:

The manual does not explicitly detail specific maintenance procedures for the JBL400 speakers. However, general best practices for speaker care would apply:

Dusting: Regularly wipe down the speaker cabinets with a soft, dry cloth to prevent dust buildup, which can affect aesthetics and potentially accumulate in driver gaps over time.
Protection from Elements: Keep the speakers away from direct sunlight, extreme temperatures, and high humidity to prevent damage to the cabinet finish and internal components.
Gentle Handling: Avoid pressing on the speaker cones or domes, as this can cause irreversible damage to the drivers.
Secure Connections: Periodically check that speaker wire connections are secure and free from corrosion to maintain optimal signal transfer.

The JBL400 is presented as a reliable and user-friendly speaker system, backed by JBL's legacy in audio engineering. The inclusion of detailed setup and troubleshooting information aims to empower users to achieve the best possible sound quality from their investment. The company also encourages users to complete a profile card to stay informed about advancements and help JBL understand customer needs for future product development.