Explanation of Enclosure Specifications

There are many different factors that help determine the best style of enclosure for you or your vehicle. Listed below are some factors that should be considered.

The size of the enclosure is directly proportional to the efficiency and power handling of that speaker. A woofer in a smaller enclosure will handle more power than the same woofer in a larger enclosure. The exact opposite is true for efficiency, a larger enclosure will play lower frequencies at a louder volume with less power than a smaller enclosure.

The following will explain differences in sealed enclosures. A large enclosure is best suited if you have smaller amounts of power (25% to 50% of speaker’s power handling), have a larger vehicle or looking for greater output. While the smaller enclosure should be utilized if you have recommended power (50% to 100% of speaker’s rated power handling), have a smaller (high gain) vehicle or are looking for more accurate sound reproduction. A smaller sealed enclosure will yield more control, this audible translates into faster and more accurate bass.

A vented enclosure will offer greater efficiency and stronger low bass output compared to a sealed design. A vented enclosure uses the back wave (sound from the back side of the cone) to reinforce the output from the speaker. A properly tuned enclosure will yield gain across the entire bandwidth of the subwoofer system and offer more cone control than a sealed enclosure. A low tuning will yield less overall gain but greater extension (low bass). A high tuned enclosure will offer more gain but limit the low end response of the system. One of the advantages of having a vented enclosure is because it is tunable to a specific frequency and that tuning frequency is known as the “Fb”. Another important box specification is “F3”, which is the roll-off frequency at which the driver's response is down -3dB. This is an important number when it comes to setting your high-pass filter or your ORION Intelli-Q. The Intelli-Q should be set at the same frequency as the “F3”as this will keep the speaker from damaging or what is know as over-loading.

Good planning and proper construction will assure the best response from your system. The next pages will outline many different enclosures and designs that allow the XTR subwoofers to perform best. As always, if you have any questions on enclosure construction or design, call Technical Support 1-800-753-0800.