<s>
The	O
Voigt	B-Architecture
pipe	I-Architecture
is	O
a	O
type	O
of	O
loudspeaker	B-Device
enclosure	I-Device
that	O
embodies	O
a	O
combination	O
of	O
transmission	B-Architecture
line	I-Architecture
,	O
ported	O
enclosure	O
and	O
horn	B-Device
characteristics	O
.	O
</s>
<s>
Due	O
to	O
its	O
relatively	O
high	O
efficiency	O
the	O
design	O
is	O
frequently	O
employed	O
in	O
full-range	B-Device
loudspeaker	O
designs	O
.	O
</s>
<s>
The	O
lower	O
part	O
of	O
the	O
pipe	O
acts	O
as	O
a	O
horn	B-Device
while	O
the	O
top	O
can	O
be	O
visualized	O
as	O
an	O
extended	O
compression	O
chamber	O
.	O
</s>
<s>
The	O
entire	O
pipe	O
can	O
also	O
be	O
seen	O
as	O
a	O
tapered	O
transmission	B-Architecture
line	I-Architecture
in	O
inverted	O
form	O
,	O
that	O
is	O
,	O
widening	O
rather	O
than	O
narrowing	O
from	O
top	O
to	O
bottom	O
.	O
</s>
<s>
The	O
Voigt	B-Architecture
pipe	I-Architecture
was	O
designed	O
in	O
1934	O
by	O
Paul	O
G	O
.	O
A	O
.	O
H	O
.	O
Voigt	O
and	O
is	O
also	O
referred	O
to	O
as	O
a	O
tapered	O
quarter-wave	O
pipe	O
(	O
TQWP	O
)	O
or	O
tapered	O
quarter-wave	O
tube	O
(	O
TQWT	O
)	O
.	O
</s>
