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.
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