Subwoofer
Subwoofer
4 5
Enclosure Types
The three most common enclosures used in the mobile audio environment
are;
sseeaalleedd,, vveenntteedd ((ppoorrtteedd))
, or
bbaannddppaassss
. Each one of these enclosures has
certain characteristics that may or may not suit your needs. In order to
choose the correct enclosure for your system, it will be necessary to
answer a few questions.
One of the most important questions is space. How much area do you
have to work with? Second, you need to know how much power your
amplifier can produce continuously. Next, decide what kind of bass you
want, tight, boomy, punchy, high sound quality, or extreme sound pressure
(SPL). Finally, decide who is going to build your box and if you will be the
wood chuck that does the work, make sure you choose a box that is not
to difficult for your skill level.
When building your enclosure or if you have a professional build it, make
sure the correct materials are used. Ample Audio recommends the use of
Medium Density Fiberboard (MDF) as the primary construction materi-
al, a high grade wood glue, premium pure silicone for sealing seams, solid
wood braces for large or high pressure enclosures, high quality fasteners
for assembly (pre-drilled and screwed for high pressure applications or
heavy gauge nailer brads for less demanding enclosures), high quality
speaker terminals, box filler when applicable, and always make sure that
the mounting area is flat and the woofer hole is the proper diameter.
The easiest type of box to build is a “Sealed Enclosure.” Sealed enclosure
offer smaller air space, good power handling at all frequencies, linear
response, and they tend to have exceptional sound quality.
When building a sealed enclosure, make sure that all of the seams are air-
tight by using a high-grade silicone. Sealed enclosures are generally cate-
gorized for tight or high sound quality applications. If the box volume is
increased, the bass will become deeper and will have a flatter response. If
you want to generate more SPL, simply make the box smaller than rec-
ommended, but keep in mind that the overall response will be inferior.
Vented (ported) enclosures are a little trickier to design and build than
sealed enclosures, but they can offer several advantages as well. The use
of vented enclosures requires 50% to 150% more space; therefore you have
to first determine whether or not you are willing to give up the room in
your vehicle or if you have enough room at all. The reasons why vented
enclosures are harder to design is because they are dependent upon a tun-
ing port. If the port size is to small or to large, the output will be very lim-
ited and there is a strong possibility that you will damage the woofer. If
the port is properly done, there can be a significant increase in output ver-
sus other types of enclosures. Other benefits include excellent deep bass
response, lower power requirements (more efficient), and extreme SPL.
Use vented enclosure for extended deep bass or strong punch.
The most difficult enclosure to design and build is known as a bandpass
box. Described by its name, a bandpass box controls both low and high fre-
quencies. These enclosures are very unique because they allow the
designer to control efficiency. Usually, however, BP boxes require the
most amount of space and cost the most to build. There are many varia-
tions to bandpass enclosures, therefore, it is usually a good idea to consult
your Authorized Dealer or call Ample Audio for designs. However, we
have included a dual chamber, single woofer design for those who want to
attempt a BP design.
Exonic SUB-manual 2/19/02 2:41 PM Page 4