PowerBass 3XL Series, Руководство пользователя

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INSTALLATION EXPERIENCE
Installation of PowerBass Xtreme Speakers requires experience with a variety of mechanical and electrical
procedures. This manual provides only general installation and operation instructions. If you have any
reservations about your installation skills or lack of the proper tools, please contact your local PowerBass
Xtreme dealer for assistance.
CHOOSING A SPEAKER ENCLOSURE
The PowerBass Xtreme 3XL Subwoofers are engineered to perform at their optimum level in a Vented (aka
Ported) enclosure. However, these subwoofers offer the versatility of being used in either sealed, vented or
bandpass enclosures. For maximum performance we recommend you have your new PowerBass Xtreme
Subwoofer installed by an Authorized PowerBass Xtreme Dealer.
• SEALED BOX: A sealed or acoustic suspension enclosure is easy to build and typically offers a smaller
size enclosure and greater power handling. It has the most predictable frequency and phase response;
the bass response will roll off slower than that of a ported design. Sealed boxes typically provide the
best musical detail and definition. A well-designed sealed enclosure will exhibit smooth frequency
response with excellent sound quality and great low bass extension. They also exhibit relatively
accurate, punchy bass reproduction for most types of music. If a sealed enclosure is too large to
fit into a specific area of a vehicle, it is possible to decrease the recommended box volume by using
1.5 pounds per cubic feet of low density, high heat specific box stuffing material. PowerBass recommends
Fiberglass, Dacron, Poly-Fill or long fiber wool for stuffing the enclosure (decreasing the box enclosure
however should not exceed 20% of the recommended size). When using any type of box stuffing
material be sure that the subwoofer’s vented pole piece is clear from any obstructions, since covering
the pole piece will result in loss of bass and can possibly cause damage to your subwoofer. The most
important aspect of a sealed enclosure is to make sure that it is airtight and solid. If your enclosure
has any air leaks or if the panels vibrate or flex, you will experience a loss of bass output. Using glue
and some type of sealant (caulk) on all seams will ensure a solid constructed box without any air leaks.
• VENTED BOX: Also known as a ported or bass reflex enclosure, this type of box is almost as easy to
construct as a sealed enclosure. This design however is more efficient and results in an increase of bass
output at certain frequencies. Although a vented enclosure has an output advantage at some frequencies,
it also has a steeper rolloff, which will only affect bass frequencies below port tuning. Air inside the port will
move in phase with the subwoofer reinforcing frequencies above the F3 (-3dB point). The SPL advantage
of the vented enclosure comes from the fact that the effect of the vent tuning reduces the excursion
of the subwoofer near the tuning frequency allowing more SPL to be produced before the subwoofer
bottoms. Damping material should also be used to line the internal walls to reduce any sonic reflection.
Because of the characteristics of a vented enclosure, subwoofers typically will become unloaded (act as if
it is not in a box) at frequencies of ½ octave below the enclosure tuning frequency. Using a high pass
filter / subsonic filter will help prevent the subwoofer from unloading or exceeding its excursion capabilities.
It is important to stay within the recommended enclosure specifications. (PowerBass recommends port
placement to coincide on the same panel or baffle that the subwoofer resides on.)