Advantages And Disadvantages of Most Popular Enclosure Designs
COMMON ENCLOSURE TYPES
In the car audio world there are 3 types of subwoofer enclosures commonly used; SEALED BOX
(closed box), VENTED BOX (bass reflex) and SINGLE-VENTED BANDPASS ( 4th order ). No single
design is superior because each has its own compromise in performance, power handling, and
design complexity.
SEALED
boxes offer one of the best compromises in power handling and performance.
Because of the “air spring” provided by the box the advantages include simple box
construction, high power handling, excellent transient response, and smooth low
frequency roll-off. Disadvantages include only moderate efficiencies at low frequencies
and the need for large box volumes.
VENTED
boxes extend the low frequency response below that of the sealed box by
using a port tube. Advantages include extended low frequency response, lower
distortion due to smaller cone movements in its passband, good efficiency, good
transient response, moderate size boxes, and high power capacity. Disadvantages
include increased complexity in box design and possible woofer damage due to over
excursion of the woofer cone below the cut-off frequency of the vented box.
SINGLE-VENTED BANDPASS
boxes are relatively new for use in the car but offer some
advantages of both the sealed and vented designs. Advantages include reasonable efficiency,
small box volumes, good transient response, extended low frequency performance, and can
be used with very high power amplifiers. Disadvantages include increased complexity in box
design and construction.
Sealed Enclosures -
The use of a sealed enclosure is not recommended unless the majority
of music listened to (Genre) is either, Classic Rock, Contemporary Rock, Heavy Metal, Jazz,
Classical, some forms of Dance and Techno or Country Western music. If one’s Genre is that
of Rap, R&B or any form of Hip Hop, the use of a vented enclosure is recommended.
Vented Enclosures -
The use of a vented enclosure is recommended when low bass extension
is desired as well as an increase in SPL level in the overall bass response .The graphs below
depict the basic difference in response between a sealed box recommendation and that of the
same driver in a vented application. The use of this type of enclosure is recommended if the main
music Genre listened to is Rap, R&B or any form of Hip Hop.
Band Pass Enclosures -
The use of a band pass type enclosure is recommended when
the full sound of bass reproduction is desired to be heard in the sitting (cabin) area of the
vehicle when the enclosure is typically mounted in another compartment, such as the trunk of
a sedan. NOTE: All or part of the port may be mounted on the outside of the enclosure.
PLEASE CALL TECH SUPPORT IN REGARDS TO THE DESIGN OF ANY TYPE OF BAND
PASS ENCLOSURE.
Typical Sealed Box Response Graph
Typical Ported Box Response Graph
Typical Bandpass Box Response Graph
Oz Audio Vector Series Subwoofer User Manual
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