<s>
A	O
full-range	B-Device
loudspeaker	O
drive	O
unit	O
is	O
defined	O
as	O
a	O
driver	O
which	O
reproduces	O
as	O
much	O
of	O
the	O
audible	O
frequency	O
range	O
as	O
possible	O
,	O
within	O
the	O
limitations	O
imposed	O
by	O
the	O
physical	O
constraints	O
of	O
a	O
specific	O
design	O
.	O
</s>
<s>
The	O
frequency	O
range	O
of	O
these	O
drivers	O
is	O
maximized	O
through	O
the	O
use	O
of	O
a	O
whizzer	B-Device
cone	I-Device
and	O
other	O
means	O
.	O
</s>
<s>
Most	O
single	O
driver	O
systems	O
,	O
such	O
as	O
those	O
in	O
radios	O
,	O
or	O
small	O
computer	B-Device
speaker	I-Device
designs	O
,	O
cannot	O
reproduce	O
all	O
of	O
the	O
audible	O
frequencies	O
or	O
the	O
entire	O
audible	O
audio	O
range	O
(	O
i.e.	O
,	O
sound	O
within	O
the	O
range	O
of	O
human	O
hearing	O
)	O
.	O
</s>
<s>
Typically	O
,	O
a	O
full-range	B-Device
drive	O
unit	O
consists	O
of	O
a	O
single	O
driver	O
element	O
,	O
or	O
voice	B-Device
coil	I-Device
,	O
used	O
to	O
move	O
and	O
control	O
a	O
diaphragm	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
small	O
low-mass	O
horn	O
or	O
whizzer	B-Device
cone	I-Device
can	O
be	O
mounted	O
where	O
the	O
voice	B-Device
coil	I-Device
and	O
diaphragm	O
meet	O
,	O
thereby	O
increasing	O
the	O
output	O
at	O
high	O
frequencies	O
.	O
</s>
<s>
Yet	O
other	O
designs	O
simply	O
modify	O
the	O
diaphragm	O
and	O
dome/whizzer	O
materials	O
instead	O
of	O
compliantly	O
coupling	O
the	O
diaphragm	O
to	O
achieve	O
full-range	B-Device
operation	O
.	O
</s>
<s>
In	O
some	O
designs	O
,	O
the	O
main	O
diaphragm	O
may	O
be	O
coupled	O
to	O
the	O
voice	B-Device
coil	I-Device
using	O
a	O
compliant	O
bond	O
such	O
that	O
high	O
frequency	O
vibrations	O
are	O
not	O
transmitted	O
into	O
it	O
,	O
but	O
instead	O
move	O
the	O
whizzer	B-Device
cone	I-Device
.	O
</s>
<s>
The	O
technique	O
of	O
using	O
a	O
compliantly	O
coupled	O
(	O
or	O
modified	O
)	O
diaphragm	O
for	O
the	O
low	O
frequencies	O
and	O
auxiliary	O
whizzer	O
or	O
modified	O
dust-cap	O
(	O
dome	O
)	O
for	O
the	O
high	O
frequency	O
response	O
of	O
a	O
speaker	O
is	O
a	O
mechanical	O
implementation	O
of	O
an	O
audio	B-Algorithm
crossover	I-Algorithm
.	O
</s>
<s>
Since	O
the	O
requirements	O
of	O
a	O
full-range	B-Device
driver	I-Device
include	O
both	O
good	O
low	O
and	O
high	O
frequency	O
response	O
(	O
which	O
are	O
contradictory	O
in	O
terms	O
of	O
physical	O
construction	O
)	O
,	O
a	O
full-range	B-Device
driver	I-Device
is	O
usually	O
limited	O
to	O
covering	O
the	O
audio	O
spectrum	O
above	O
perhaps	O
100Hz	O
—	O
leaving	O
lower	O
frequencies	O
to	O
be	O
handled	O
/	O
augmented	O
by	O
a	O
separate	O
sub	B-Application
woofer	I-Application
or	O
by	O
a	O
special	O
cabinet	O
design	O
for	O
low	O
frequency	O
reinforcement	O
.	O
</s>
<s>
These	O
requirements	O
usually	O
mean	O
that	O
the	O
full-range	B-Device
must	O
have	O
good	O
sensitivity	O
(	O
for	O
lower	O
frequencies	O
)	O
with	O
a	O
light	O
voice	B-Device
coil	I-Device
(	O
for	O
high	O
frequencies	O
)	O
these	O
speakers	O
commonly	O
use	O
a	O
larger	O
or	O
more	O
powerful	O
magnet	O
than	O
usual	O
,	O
which	O
improves	O
sensitivity	O
and	O
thus	O
lowers	O
the	O
power	O
requirement	O
at	O
low	O
frequencies	O
as	O
well	O
as	O
allowing	O
a	O
lighter	O
voice	B-Device
coil	I-Device
.	O
</s>
<s>
In	O
addition	O
,	O
many	O
have	O
limited	O
maximum	O
excursions	O
,	O
requiring	O
special	O
enclosures	B-Device
which	O
do	O
not	O
require	O
large	O
excursions	O
at	O
low	O
frequencies	O
for	O
reasonable	O
low	O
end	O
output	O
.	O
</s>
<s>
There	O
are	O
rare	O
exceptions	O
that	O
use	O
multiple	O
elements	O
to	O
drive	O
a	O
common	O
diaphragm	O
,	O
but	O
these	O
should	O
not	O
be	O
confused	O
with	O
coaxial	B-Device
speakers	I-Device
that	O
use	O
separate	O
and	O
concentrically	O
aligned	O
elements	O
to	O
achieve	O
the	O
desired	O
range	O
of	O
reproduction	O
,	O
and	O
are	O
not	O
,	O
strictly	O
,	O
classified	O
as	O
full-range	B-Device
drivers	I-Device
.	O
</s>
<s>
Full-range	B-Device
drivers	I-Device
are	O
seen	O
in	O
applications	O
ranging	O
from	O
televisions	O
and	O
computer	B-Device
speakers	I-Device
,	O
to	O
hi-fi	O
speaker	O
systems	O
.	O
</s>
<s>
The	O
performance	O
of	O
the	O
driver	O
is	O
substantially	O
affected	O
by	O
their	O
enclosure	O
,	O
and	O
enclosures	B-Device
vary	O
from	O
mundane	O
beige	O
plastic	O
boxes	O
,	O
at	O
the	O
low	O
end	O
of	O
the	O
scale	O
,	O
to	O
large	O
horn	O
loaded	O
enclosures	B-Device
with	O
spectacular	O
audio	O
performance	O
.	O
</s>
<s>
A	O
German	O
company	O
,	O
Manger	O
,	O
produces	O
an	O
unusual	O
full-range	B-Device
driver	I-Device
in	O
the	O
form	O
of	O
a	O
differentially	O
flexing	O
flat	O
diaphragm	O
driver	O
,	O
about	O
eight	O
inches	O
in	O
diameter	O
.	O
</s>
<s>
Manger	O
claims	O
performance	O
,	O
both	O
maximum	O
level	O
and	O
extended	O
low	O
frequency	O
response	O
,	O
which	O
is	O
rather	O
better	O
than	O
traditional	O
full-range	B-Device
drivers	I-Device
.	O
</s>
<s>
Another	O
unusual	O
full-range	B-Device
driver	I-Device
design	O
is	O
the	O
Walsh	O
driver	O
,	O
popularized	O
in	O
Ohm	O
hi-fi	O
speaker	O
systems	O
,	O
where	O
they	O
reproduced	O
almost	O
the	O
entire	O
audible	O
range	O
of	O
frequencies	O
.	O
</s>
<s>
Loudspeakers	O
using	O
the	O
Walsh	O
driver	O
are	O
still	O
in	O
production	O
,	O
though	O
they	O
have	O
adopted	O
a	O
tweeter	B-Device
so	O
no	O
longer	O
qualify	O
as	O
full-range	B-Device
drivers	I-Device
.	O
</s>
<s>
Large	O
electrostatic	B-Device
loudspeakers	I-Device
may	O
be	O
considered	O
as	O
full-range	B-Device
speakers	I-Device
in	O
the	O
sense	O
that	O
they	O
are	O
capable	O
of	O
reproducing	O
most	O
of	O
the	O
audio	O
frequency	O
band	O
.	O
</s>
<s>
Full-range	B-Device
drive	O
units	O
may	O
be	O
found	O
in	O
applications	O
ranging	O
from	O
inexpensive	O
multimedia	O
loudspeakers	O
to	O
more	O
costly	O
esoteric	O
systems	O
,	O
the	O
latter	O
often	O
using	O
large	O
transmission	O
line	O
or	O
horn	O
loaded	O
enclosures	B-Device
to	O
increase	O
low	O
frequency	O
output	O
.	O
</s>
<s>
There	O
is	O
an	O
active	O
hobbyist	O
speaker	O
construction	O
group	O
on	O
the	O
Web	O
focusing	O
on	O
full-range	B-Device
drivers	I-Device
and	O
enclosures	B-Device
for	O
them	O
.	O
</s>
<s>
A	O
large	O
number	O
of	O
full-range	B-Device
drive	O
units	O
are	O
used	O
in	O
commercial	O
sound	O
systems	O
,	O
which	O
may	O
employ	O
a	O
number	O
of	O
200mm	O
(	O
8	O
"	O
)	O
full-range	B-Device
drivers	I-Device
,	O
mounted	O
into	O
suspended	O
ceilings	O
or	O
small	O
'	O
back-box	O
'	O
enclosures	B-Device
.	O
</s>
<s>
While	O
these	O
drivers	O
are	O
classed	O
as	O
'	O
full-range	B-Device
'	O
,	O
it	O
may	O
be	O
more	O
accurate	O
to	O
term	O
them	O
'	O
wide-range	O
'	O
drivers	O
,	O
since	O
their	O
output	O
abilities	O
rarely	O
extend	O
to	O
the	O
extremes	O
of	O
the	O
frequency	O
range	O
.	O
</s>
<s>
Several	O
manufacturers	O
build	O
small	O
(	O
typically	O
115mm	O
(	O
4.5	O
"	O
)	O
)	O
diameter	O
full-range	B-Device
drivers	I-Device
into	O
miniature	O
enclosures	B-Device
,	O
and	O
many	O
of	O
these	O
include	O
25	O
or	O
70-volt	O
line	O
transformers	O
,	O
for	O
use	O
on	O
commercial	O
sound	O
systems	O
employing	O
long	O
speaker	O
cables	O
.	O
</s>
<s>
Some	O
full-range	B-Device
speaker	I-Device
systems	O
are	O
designed	O
with	O
limited-range	O
drivers	O
,	O
and	O
must	O
be	O
used	O
with	O
equalizers	O
to	O
flatten	O
and	O
extend	O
their	O
frequency	O
response	O
,	O
while	O
others	O
achieve	O
acceptable	O
response	O
without	O
electronic	O
assistance	O
.	O
</s>
<s>
There	O
are	O
full-range	B-Device
speaker	I-Device
systems	O
using	O
up	O
to	O
15	O
"	O
single	O
drivers	O
.	O
</s>
<s>
Partisans	O
of	O
full-range	B-Device
loudspeakers	O
claim	O
superior	O
phase	O
coherence	O
,	O
while	O
some	O
critics	O
describe	O
them	O
as	O
midrange	B-Device
speakers	I-Device
working	O
at	O
or	O
beyond	O
their	O
limits	O
.	O
</s>
