CHOOSING AN ENCLOSURE

WARNING: Playing loud music in an automobile can permanently damage your hearing as well as hinder your ability to hear traffic. We recommend listening at low levels while driving. JBL accepts no liability for hearing loss, bodily injury or property damage resulting from use or misuse of this product.

Grand Touring Series subwoofers are optimized to perform best in small, sealed, vented and prefabri- cated bandpass enclosures. While infinite-baffle mounting of GTO subs is possible, power handling will be greatly compromised because there’s no enclosed volume of air to prevent the speaker’s cone from moving past its limit. For this reason, we do not recommend infinite-baffle mounting for GTO subwoofers.

You should choose the enclosure you will use based on the type of music you listen to, how much amplifier power you will use for the subwoofer and how much space inside the vehicle you can devote to a subwoofer enclosure.

Because a sealed enclosure provides the most control over the woofer’s movement, a woofer mounted in a sealed enclosure will handle more power than a woofer mounted in another enclosure type. Sealed enclosures provide more accurate sonic reproduction than other enclosure types when mounted inside a vehicle, so they are well-suited to all types of music. Sealed-enclosure construction is straightforward and there are many

prefabricated sealed enclosures available. An optimum sealed enclosure is always smaller than other types of enclosures optimized for a particular speaker, so they require the smallest amount of space inside the vehicle.

Vented enclosures provide better efficiency in the 40Hz – 50Hz range but this efficiency comes at the expense of sound in the lowest octave (below 40Hz) and at the expense of some control and power handling at the lowest frequencies. If you are using a small amplifier, a vented box will provide more perceived bass output from less power. Vented enclosures are also well-suited to a variety of music types. Because vented enclosures require the volume of the enclosure and the size of the port to have

a specific relationship with the characteristics of the woofer, the enclosure must be built exactly to the specifications provided. While there are some prefabricated vented boxes available, matching a prefabricated box to a particular woofer is difficult. If you wish to use a vented enclosure, we strongly recommend having your authorized JBL dealer build it or verify that your

design is correct if you wish to build it yourself. An optimum vented enclosure is always larger than the optimum sealed box for the same woofer and will require more space inside the vehicle.

Bandpass enclosures often provide the most output available from any amplifier and subwoofer combination at the expense of sonic accuracy.

If sheer SPL (sound-pressure level) is what you desire most, choose a bandpass enclosure. Bandpass- enclosure design is very tricky and the aid of a computer and enclosure design software is necessary. If you are an experienced installer or have some woodworking experience, you may wish to build the bandpass enclosure described in the enclosure design sheet included with this woofer. Fortunately, there are many prefabricated bandpass boxes available and they are all optimized to extract the most output possible from any woofer. Bandpass enclosures can be quite large and may require a lot of space inside your vehicle.

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JBL GTO804, GTO1004D, GTO1002D, GTO1204D, GTO1502D, GTO1202D, GTO1504D owner manual Choosing AN Enclosure
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GTO1504D, GTO1004D, GTO1502D, GTO1002D, GTO1204D specifications

JBL has long been a leader in the car audio industry, and their GTO series is a testament to their commitment to superior sound quality and innovative technologies. The GTO804, GTO1204D, GTO1202D, GTO1002D, and GTO1502D are prime examples of this dedication, each model designed to cater to specific listening preferences and installation needs.

The JBL GTO804 is an 8-inch subwoofer that packs a punch in a compact size. With a peak power handling of 800 watts and a RMS rating of 200 watts, it delivers deep and powerful bass with minimal distortion. Its patented Plus One cone technology allows for a larger cone surface area, which improves the bass output while maintaining sound clarity. The GTO804 is especially suited for smaller vehicles or as part of a more extensive sound system where space is a concern.

Moving up in size, the GTO1204D is a 12-inch subwoofer that takes performance to the next level. It features a dual 4-ohm voice coil design, allowing for versatile wiring options to match the amplification requirements. With a peak power handling of 1200 watts and an RMS rating of 300 watts, this subwoofer loves to hit hard, producing rich lows that can satisfy any bass enthusiast. Its durable rubber surround and polypropylene cone contribute to longevity and performance consistency.

The GTO1202D is another excellent 12-inch option, known for its high sensitivity and robust build. This model shares many characteristics with the GTO1204D but has a lower RMS power handling at 250 watts and is designed for those who desire powerful bass without overcomplication. Its performance is backed by a unique vented pole piece that helps maintain voice coil temperature, ensuring flexibility in after-hours sessions.

For those looking for a smaller dual-subwoofer setup, the GTO1002D, a 10-inch option, offers an impressive balance of size and power. The dual 2-ohm voice coils allow for both series and parallel connections, making it versatile for various amplifier configurations. With a peak power of 1000 watts, it serves up solid performance while fitting comfortably into more compact enclosures.

Finally, the GTO1502D stands as the powerhouse of the GTO series. With a 15-inch design, this subwoofer delivers explosive bass and showcases enhanced power handling with a peak of 1500 watts and an RMS rating of 400 watts. It's constructed with durable materials that ensure longevity and comes equipped with features like a unique rubber surround for greater excursion and support during high-output scenarios.

Each model in the JBL GTO series is engineered with the latest sound technologies, making them not only powerful but also reliable in different vehicle acoustics. With their advanced design and engineering, these subwoofers are a fantastic addition for any car audio aficionado looking to elevate their listening experience.
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