-5- UL
TIMA
TE PERFORMANCE SUBW
OOFERS & MIDB
ASS
-4- UL
TIMA
TE PERFORMANCE SUBW
OOFERS & MIDB
ASS
BRA
V
O
X UL
TIMA
TE PERFORMANCE SUBW
OOFERS
ha
ve
T
hiele/Small par
ameters more suitable for oper
ation in closed enclosures, but can
also pro
vide good results w
hen installed in v
ented enclosures
(SVC models only).
While it is possible for the ad
vanced installer to use the
T
hiele/Small par
ameters p
ro
vided in the c
hart at page 2 to design their o
wn enclosures (for more on “doing it y
ourself”, c
hec
k out
V
ance
Dic
kason’
s Loudspeaker Design Cookbook, 6th Edition at www
.audioXpress.com), all this w
ork has been done for y
ou and pro
vided i
n the
recommended enclosure c
harts.
T
he c
hoice of w
h
ic
h
type o
f
enclosure, v
ented or sealed, is strictly up to y
ou.
As a rule, sealed enclosures
pro
vide better
tr
ansient (read that “quic
ker”) bass response than their v
ented counterparts, although the v
ented
enclosures gener
ally pro
vide more
deep bass.
Your c
hoice should be based on the amount of space a
vailable and the size of the v
ehicle. In gener
al, smaller v
ehi
cles (Corv
ettes to
Camry’
s) probably w
ork best with sealed enclosures w
hile larger v
ehicles suc
h as SUV’
s,
V
ans, large truc
ks or R
V
’s
can benefit
from the kind of
performance a
vailable from v
ented enclosures. Ho
wev
e
r,
both enclosure types will w
o
rk in an
y
si
tu
at
io
n
.
T
his enclosure is made up of a totally closed, air
-tight box.
This type of enclosure gi
ves excellent, tight bass response, as
well as pro
viding an
effecti
ve
control of loudspeaker excursion, maintaining it within reasonable limits and gener
ally pro
viding lo
wer distortion an
d v
ery high v
olume
lev
els. If y
ou build y
our o
wn enclosure,
BRA
V
O
X
recommends that y
ou glue and screw all joints using enough glue to ensure that all joints are
air
-tight.
V
ented enclosures are not air
-tight and incorpor
ate an additional opening kno
wn as a port or v
ent, w
h
ic
h is gener
ally fabricate
d from either
plastic or cardboard tubing.
The port augments the sound coming out of the w
oofer and is in most cases capable of going lo
wer
in frequenc
y
than the same w
oofer in a sealed box. Ev
en though v
ented enclosures are not air
-tight, y
ou should follo
w the same procedure as
with sealed
boxes and glue and screw together all joints.
Table in page 6 sho
ws the internal v
olume (Vb) in liters and cubic feet for sealed and v
ented enclosures, specifically designed
for
UL
TIMA
T
E
PERFORMANCE SUBW
OOFERS
. F
or sealed enclosures there are options for normal and for “enhanced” bass response (note: the normal
response enclosure pro
vides more accur
ate bass w
hile the smaller “enhanced” bass enclosures are somew
hat less accur
ate, but ha
ve marginally
increased po
wer handing). Intermediate v
o
lumes to those sho
wn on the table ma
y also be
used, with corresponding results between a
normal
response and one with enhanced bass response. F
o
r v
ented enclosures there are tw
o options for normal and “enhanced” bass response, but in
this case, r
ather than c
hanging the v
olume of the enclosure, a different tuning (v
ent length) is used.
T
he dimensions sho
wn in the tables are intended as a guideline and specific dimensions (HxWxD) ma
y be c
hanged pro
vided the inte
rnal
volume of the enclosure is maintained. Please note that the internal vo
lu
m
e
s
sh
ow
n
i
n
t
h
e
t
a
b
le
a
lr
e
a
d
y
take in account v
o
lume occupied b
y
dri
ve
r and port. F
o
r best
performance the w
alls of the enclosure should be rigid and not vibr
ate as a result of the internal pressures gener
ated
b
y
the loudspeakers.
BRA
V
O
X
recommends constructing enclosures from medium-density fiberboard (MDF) with a minimum thic
kness of 3/4”. F
or
larger 12” and 15” subw
oofers it is desir
able to use 1” thic
k MDF
. In larger enclosures o
ver 1 cubic foot, internal br
acing tha
t joins opposite
w
alls can be incorpor
ated and the final enclosure should be as rigid as possible.
All joints should be glued and fastened with
screws.
Additionally
, internal joints can be co
vered with a small bead of silicone adhesi
ve
to ensure that the enclosure is completely
air
-tight.
UL
TIMA
T
E
PERFORMANCE SUBW
OOFERS
are all moder
ately hea
vy for their size and should be fastened to the enclosure with self-threading screws with
adequate length and diameter
, utilizing all the mounting holes in the fr
ame.
To
a
void air leakage, a foam rubber gasket or simi
lar sealing method
should be applied between the loudspeaker and the enclosure.
The external surface of the enclosure ma
y be painted or fabric-co
vered, to suit
the consumer
.
Since lo
w frequenc
y sounds are not directional, subw
oofer enclosures can gener
ally be placed an
yw
here
within the car
, without compromising
stereo imaging.
While the trunk is the most ob
vious location,
locating them behind the seats is another possibility
. Ho
wev
e
r,
different
placement locations of
subw
oofer enclosures can sometimes influence the o
ver
all quality of bass/midbass response.
As interior acoustics are
different for eac
h v
ehicle, y
ou ma
y wish to experiment with v
arious mounting locations before permanently mounting the w
oofer
.
VENTED (B
ASS REFLEX) ENCLOSURES
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ENCLOSURES
CONSTRUCTION AND
INST
ALLA
TION
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TION -
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