XTI SUB 300 - Subwoofer JBL - Free user manual and instructions

Product Type	Passive Subwoofer
Brand	JBL
Model	XTI SUB 300
Recommended Distance from Walls	At least 75 cm from the rear wall, 75 cm to 1 m from side walls
Listening Positioning	Equilateral triangle relative to listening position
Recommended Cable Gauge	Minimum 1 mm² for distances <5 m, heavier gauge for longer lengths
Connection Type	Binding posts with bi-wiring options
Bi-wiring	Possible by removing jumper bars
Spikes	Yes, supplied for mechanical decoupling
Removable Grille	Yes, held by studs
Maintenance	Dust with a soft dry cloth; stains: non-ammonia glass cleaner on cloth
Break-in	8 to 12 hours of operation for maximum efficiency
Cabinet Material	Luxurious materials (not specified)
Protection	No fuse or circuit breaker between amplifier and speakers
Warranty	Not specified

Frequently Asked Questions - XTI SUB 300 JBL

How should I position my XTI SUB 300 subwoofer for optimal sound?

For optimal performance, place your subwoofer to form an equilateral triangle with your listening position. Keep it at least 75 cm from the rear wall and 75 cm to 1 m from side walls. An authorized JBL dealer can help refine this placement.

What is the minimum distance to maintain between the subwoofer and walls?

It is recommended to leave at least 75 cm behind the subwoofer and 75 cm to 1 m on the sides. This avoids unwanted reflections and optimizes bass response.

How do I connect my subwoofer to the amplifier?

Before any connection, ensure the amplifier is turned off. Use speaker cables of at least 1 mm² for distances under 5 meters. Connect the stripped wires (8-10 mm) to the binding posts respecting polarity (red terminal for positive). Avoid any loose strands that could cause a short circuit.

What is bi-wiring and how do I implement it?

Bi-wiring consists of connecting the amplifier to each section of the internal filter (bass and mid-high) with separate cables. To do this, remove the original jumper bars between the terminals. Use four conductors (two pairs): one pair for bass, one for mid-high. This reduces interference and improves clarity. Never connect two amplifiers without removing the jumpers.

How do I adjust the spikes on my subwoofer?

The spikes are inserted into the threads at the four corners of the base. Adjust each spike so that it is firmly in contact with the floor, then tighten the lock nuts. This ensures good mechanical decoupling and optimal stability.

How do I clean the grille and cabinet of the subwoofer?

For the grille, gently brush it or use a vacuum cleaner. For the cabinet, dust with a soft, dry cloth. For stains, use a non-ammonia glass cleaner sprayed on the cloth, then wipe gently. Never use solvents or abrasives.

Why do my speakers seem out of phase?

A polarity inversion between speakers can cause loss of stereo image and reduced bass. Check that the red terminals are connected to the positive of the amplifier. To test, reverse the cables on one speaker and listen: if the bass is stronger, the speakers were out of phase. Correct by reversing both speakers simultaneously.

What should I do if a speaker stops working?

Start by checking the entire wiring. Swap the cables between speakers: if the problem follows the cable, the cable is defective; if it stays on the same speaker, the issue is internal. In that case, contact your authorized JBL dealer. Never return a product without prior authorization.

Can I use a cable with a gauge smaller than 1 mm²?

For distances under 5 meters, a gauge of 1 mm² is the minimum recommended. A smaller gauge would increase resistance and could degrade sound quality, especially in the bass. For longer lengths, use a heavier gauge to avoid losses.

How long does it take to break in my subwoofer?

New speakers require a break-in period of 8 to 12 hours of operation to reach maximum efficiency. During this time, use varied music at a moderate volume to allow the suspensions to loosen.

USER MANUAL XTI SUB 300 JBL

JBL craftsmen have been involved in the art of sound for more than two generations – signal and source, wood and fabric, transducers and acoustics – all of it.

JBL loudspeakers are carefully engineered instruments, painstakingly crafted and assembled to watchmaker standards. JBL transducers and electronics offer what has been characterized by devoted music listeners as "the incomparable JBL sound".

By following the few simple suggestions contained in this booklet, you can look forward to superb high fidelity reproduction that will retain its clarity and realism year after year.

We strongly suggest that you keep the packing material for future purposes, in case you are moving or your loud-speakers should require service.

PLACEMENT

Your JBL XTi-Series speakers offer satisfying sound in a great variety of listening rooms when set up in an equilateral triangle with respect to the listener. However, careful setup will always be rewarded, and for best results we recommend placement well away from the boundaries of the room with preferably minimum 0.75 m (30 in) distance to the wall behind the speakers, and 0.75-1.0 m (30-40 in) distance to the side walls.

Your authorized JBL dealer will be happy to help you obtain the best possible performance from your JBL speakers.

NOTE: New loudspeakers require a certain amount of "exercise" before they perform their best. A steady level of performance is achieved after 8-12 hours of operation, depending on the nature of the music and the level.

CONNECTIONS

IMPORTANT: When connecting or disconnecting loudspeakers from an amplifier, the amplifier must be turned off. Making connections while the amplifier is operating could seriously damage the loudspeaker system and void the warranty. The amplifier must also be turned off before connecting or disconnecting cables, at the amplifier or pre-amplifier inputs.

1mm^2 (18 AWG) insulated wire is the minimum size recommended for loudspeaker connection up to 5 meters (16 ft). Beyond this distance, heavier gauge wire is recommended.

Speaker wire and interconnect cables are important components in an audio system. With all other factors at an appropriate level of quality the speaker cable and the interconnect cable can make significant contributions to the perceived sound quality. Careful selection of cable and interconnect can add or subtract marked shadings in the tonal character. Likewise, different cables can have quite a dramatic impact on the dynamic contrasts experienced by listeners.

Your JBL dealer has the experience and knowledge to recommend suitable interconnects and speaker wire to best complement your system.

Connections to the loudspeaker system are made at the terminals located on the back of the enclosure. These terminals permit a variety of connection methods.

The most straightforward connection is made by directly connecting clean bare wire. This connection is made by stripping 8 - 10mm of insulation off the loudspeaker wire and passing the bare wire through the hole in the binding post. The knob can now be tightened securely, and any excess wire that is not in contact with the binding post surfaces should be trimmed to avoid short circuits.

A very convenient way of connection is the use of 4 mm banana connectors, which are then, in turn, connected to the binding posts. Bear in mind, however, that the number of contact points should be kept to a minimum, and at the same time each contact should be as tight as possible.

For the same reason, we recommend the use of the highest quality spade connectors, expertly connected to the selected cables. Spade lugs will make the best possible connection between the speaker wire and the loudspeaker system, minimizing any contact resistance that might degrade the sound ever so slightly.

It is essential that both loudspeakers in a stereo system have the same polarity with respect to the input signal (are in "phase"). JBL XTi-Series are designed to produce a positive pulse when a positive signal is applied to the red input terminal.

If the driver cones of the two loudspeakers do not move in the same direction for a given voltage at the input terminals, there will be a lack of stereo definition and a loss of deep bass.

We recommend experimenting with the polarity of the speakers, since recordings, program sources or power amplifiers can invert the polarity of the signal. The "correct" connection is the one that yields the best audible results. Be sure to reverse both left and right connections to keep the systems in polarity.

BIWIRING

JBL XTI-Series loudspeakers may be connected to the amplifier using two lengths of wire for each speaker. The "biwire" connection method offers several options and advantages.

The system's internal dividing networks are electrically separated at the low frequency to midrange/tweeter transition. External strapping bars connect the two parts of the network when a single wire connection is used. The system is shipped from the factory with the strapping bars in place. By removing the bars, connections may be made to the individual network sections using two wires (four conductors) as shown in Figure 1. The wires used may be of the same type for both low frequency and high frequency sections. The advantages are that wire effect (resistance, inductance, etc.) are reduced and intermodulation of low and high frequencies in the cable are avoided.

CAUTION: Never connect two amplifiers to the same loudspeaker without first removing the strapping bars. Operating two amplifier channels with the bars in place may seriously damage the amplifiers and void the warranty.

Fig. 1: XTi input

AMPLIFIER POWER

RECOMMENDATIONS

The JBL XTi-Series speakers are capable of handling peak power far exceeding the continuous rating specified for the individual speakers.

The continuous ratings are based on an eight hour test using broadband noise shaped to simulate the power distribution of music. The peak rating of approximately 4 times the continuous rating indicates the system's ability to handle transient peaks well above the average power levels.

Amplifier power ratings are an INDICATION of how loud the system will play without distortion. Amplifier power is generally measured with steady state test signals and perhaps, in addition, dynamic measurements into resistive loads. Unfortunately none of these are firm indications of how loud the system will sound in a given listening room.

For these reasons, an amplifier should only be chosen after careful listening. If it is possible to achieve the desired volume level without distortion, then the amplifier has sufficient power regardless of the rating.

Fuses or circuit breakers of any kind should not be used between the amplifier and loudspeakers. All such devices will seriously degrade the sound quality and do not ensure protection from loudspeaker damage. The key to safe operation is adequate amplifier power to avoid distortion at the highest sound levels required.

SPIKES

The JBL XTi-speaker can be fitted with "spikes" for the best possible mechanical contact to the floor. In each corner of the bottom of the speaker is a threaded insert that allows insertion of the spikes supplied with each speaker. When mounting the spikes please make sure that each spike has good contact to the floor beneath the speaker before tightening the nuts on each spike.

GENERAL CARE

JBL XTi-Series loudspeaker systems are finished in materials that will retain its finish for many years to come. Occasional cleaning with a clean, soft cloth will maintain the original beauty of the finish. Only lint-free cotton cloths should be used for dusting. To remove fingerprints and smudges, an ammonia-free window cleaner may be used. Apply a small amount to a lint-free cotton cloth and gently clean the surface. Never use any abrasive cleaners or strong chemical to clean the enclosure. In case of deep

scratches or damage, please consult a qualified furniture repair shop.

GRILLE

The grille is held in place by a pin located at each corner. To remove the grille, grasp two corners and gently pull the grille away from the enclosure. To replace the grille, position the mounting pins on the cups and gently press until the grille meets the enclosure. Although the grille has been engineered to minimize acoustical interference, high frequency response and stereo imaging will be improved by removing the grille.

Any dust on the grille should be removed using a cleaning brush or a vacuum cleaner.

SERVICE

JBL loudspeakers are designed to give years of trouble-free service. No periodic maintenance is required. If a problem is suspected, first make sure all connections are properly made. If a problem exists in one loudspeaker, reverse the speaker wires to the left and right system. If the problem remains in the same system, then the fault is in the loudspeaker. If the problem appears in the opposite system, the cause is in another component or cable.

Do not return products to the JBL factory without prior authorization.

Address correspondence to:

JBL Customer Service, 2, route du Tours,

72500 Château-du-Loir, France

or your local JBL dealer

JBL Customer Service,

2, route du Tours,

72500 Château-du-Loir, France

Harman Consumer Belgium

Bosdellestraat 120

1933 Sterrebeek

INTRODUKTION

JBL Customer Service

2 Route du Tours

72500 Château-du-Loir, France

JBL Consumer Products

250 Crossways Park Drive, Woodbury, NY

A Harman International Company

Design: Rasmussen, G

Photography: Graae & Bangsbo Fotografi

Printed in Denmark by From & Co.

JBL constantly strives to improve our products. New materials,

production methods and design refinements are introduced into existing models without notice as a routine expression of our design philosophy. For this reason, the XTI Series loudspeakers

may differ in some respects from the published specifications and descriptions, but will always equal or exceed the original specifications unless otherwise stated.