JBL W15GTi, W10GTi, W12GTi owner manual Pro Powertm, Choosing an Enclosure

Choosing an Enclosure

GTi Series subwoofers are optimized to perform best in small sealed, vented and bandpass enclosures. While infinite-baffle mounting of GTi Series subs is possible, power handling will be compromised since there will be no enclosed volume of air to help the speaker’s suspension control the motion of the woofer’s cone. For this reason, we do not recommend infinite- baffle mounting for high-power applications.

You should choose the enclosure you’ll use based on the type of music you listen to, how much amplifier power you’ll use to drive the subwoofer, and how much space inside the vehicle you can devote to a subwoofer enclosure. If you’ll be using your GTi Series subwoofer for SPL competition, please see the document titled “GTi as SPL Competition Subwoofers” (included with your woofer).

Because a sealed enclosure provides the most control over the woofer’s movement, a woofer mounted in a sealed enclosure will handle more power at low frequencies than a woofer mounted in another enclosure type. Sealed enclosures provide more accurate sonic reproduction than other enclosure types, so they are well suited

to all types of music. Sealed-enclosure construction is straightforward. An optimum sealed enclosure is always smaller than other types of enclosures that are optimized for a particular speaker, so they require the least space inside the vehicle.

Vented enclosures provide better efficiency in the 40Hz – 60Hz range, but this efficiency comes at the expense of sound output in the lowest octave (below 40Hz) and at the expense of some control and power handling below box tuning. If you are using a small amplifier, a vented box will provide more 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. 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.

PRO POWERTM

Bandpass enclosures can provide the greatest 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 vented or bandpass enclosure. Bandpass enclosure design is very tricky and the aid of a computer and enclosure design software is necessary if you wish to design the enclosure yourself. Like a vented enclosure, a bandpass enclosure must be built exactly to the specifications provided. Bandpass enclosures can be quite large and may require a lot of space inside your vehicle.

03