<s>
A	O
coaxial	B-Device
loudspeaker	I-Device
is	O
a	O
loudspeaker	O
system	O
in	O
which	O
the	O
individual	O
driver	O
units	O
radiate	O
sound	O
from	O
the	O
same	O
point	O
or	O
axis	O
.	O
</s>
<s>
Two	O
general	O
types	O
exist	O
:	O
one	O
is	O
a	O
compact	O
design	O
using	O
two	O
or	O
three	O
speaker	B-Device
drivers	I-Device
,	O
usually	O
in	O
car	O
audio	O
,	O
and	O
the	O
other	O
is	O
a	O
two-way	O
high-power	O
design	O
for	O
professional	O
audio	O
,	O
also	O
known	O
as	O
single-source	O
or	O
dual-concentric	B-Device
loudspeakers	I-Device
.	O
</s>
<s>
Coaxial	B-Device
loudspeakers	I-Device
in	O
professional	O
audio	O
enable	O
sound	O
from	O
two	O
drivers	O
to	O
come	O
from	O
one	O
source	O
.	O
</s>
<s>
This	O
characteristic	O
allows	O
a	O
wider	O
field	O
of	O
listening	O
to	O
a	O
synchronized	O
summation	O
of	O
speaker	B-Device
drivers	I-Device
than	O
loudspeaker	B-Device
enclosures	I-Device
containing	O
physically	O
separated	O
drivers	O
.	O
</s>
<s>
Since	O
the	O
1943	O
introduction	O
of	O
the	O
Altec	B-Device
Lansing	I-Device
Duplex	I-Device
601	O
coaxial	O
driver	O
,	O
recording	O
studio	B-Device
monitors	I-Device
have	O
often	O
been	O
coaxial	B-Device
loudspeaker	I-Device
designs	O
.	O
</s>
<s>
In	O
1945	O
the	O
improved	O
Altec	O
604	O
was	O
introduced	O
,	O
and	O
it	O
soon	O
became	O
the	O
recording	O
industry	O
standard	O
studio	B-Device
monitor	I-Device
in	O
the	O
U.S.	O
First	O
shown	O
in	O
1947	O
in	O
England	O
,	O
the	O
Tannoy	O
Dual	B-Device
Concentric	I-Device
design	O
assumed	O
the	O
same	O
role	O
across	O
Europe	O
from	O
the	O
1950s	O
onward	O
.	O
</s>
<s>
The	O
Altec	O
604	O
combined	O
a	O
woofer	B-Device
with	O
a	O
compression	B-Device
driver	I-Device
attached	O
to	O
a	O
horn	B-Device
to	O
carry	O
the	O
high	O
frequencies	O
.	O
</s>
<s>
The	O
Tannoy	O
also	O
used	O
a	O
15-inch	O
woofer	B-Device
and	O
a	O
compression	B-Device
driver	I-Device
for	O
high	O
frequencies	O
,	O
but	O
differed	O
in	O
that	O
the	O
woofer	B-Device
itself	O
served	O
as	O
the	O
final	O
horn	B-Device
flare	O
for	O
the	O
high	O
frequency	O
driver	O
.	O
</s>
<s>
One	O
drawback	O
of	O
the	O
design	O
is	O
the	O
production	O
line	O
difficulty	O
in	O
mating	O
the	O
two	O
drivers	O
,	O
and	O
in	O
replacing	O
or	O
reconing	O
the	O
woofer	B-Device
.	O
</s>
<s>
The	O
Tannoy	O
style	O
of	O
coaxial	O
,	O
with	O
the	O
woofer	B-Device
forming	O
part	O
of	O
the	O
high	O
frequency	O
horn	B-Device
,	O
had	O
greater	O
intermodulation	O
distortion	O
.	O
</s>
<s>
Designs	O
similar	O
to	O
the	O
Altec	O
604	O
have	O
further	O
problems	O
with	O
diffraction	O
of	O
the	O
low	O
frequencies	O
around	O
the	O
central	O
horn	B-Device
,	O
and	O
with	O
rearward	O
emanations	O
from	O
the	O
horn	B-Device
body	O
reflected	O
forward	O
by	O
the	O
woofer	B-Device
out	O
of	O
time	O
with	O
direct	O
sound	O
.	O
</s>
<s>
The	O
Altec	O
604	O
was	O
given	O
this	O
elaborate	O
new	O
crossover	O
feature	O
and	O
incorporated	O
into	O
the	O
UREI	O
813	O
studio	B-Device
monitor	I-Device
,	O
which	O
also	O
had	O
a	O
second	O
woofer	B-Device
physically	O
separate	O
from	O
the	O
coaxial	O
pair	O
.	O
</s>
<s>
In	O
1977	O
,	O
Bob	O
Cavin	O
of	O
McCune	O
Sound	O
in	O
San	O
Francisco	O
modified	O
the	O
Altec	O
604	O
for	O
the	O
McCune	O
SM-4	O
,	O
a	O
large	O
proprietary	O
stage	O
wedge	O
,	O
using	O
John	O
Meyer	O
's	O
patented	O
high-compliance	O
compression	B-Device
driver	I-Device
diaphragm	O
,	O
a	O
higher-power	O
woofer	B-Device
,	O
and	O
processor-controlled	O
bi-amplification	O
with	O
line-level	O
all-pass	O
time	O
alignment	O
.	O
</s>
<s>
In	O
the	O
2000s	O
,	O
digital	B-General_Concept
signal	I-General_Concept
processing	I-General_Concept
(	O
DSP	O
)	O
was	O
used	O
by	O
Fulcrum	O
Acoustic	O
to	O
reduce	O
some	O
of	O
the	O
coaxial	O
drawbacks	O
such	O
the	O
diffraction	O
of	O
the	O
woofer	B-Device
's	O
upper	O
range	O
around	O
the	O
central	O
horn	B-Device
,	O
by	O
filling	O
in	O
this	O
"	O
shadow	O
"	O
with	O
low	O
frequency	O
sound	O
from	O
the	O
compression	B-Device
driver	I-Device
,	O
and	O
by	O
countering	O
the	O
out-of-time	O
reflections	O
bouncing	O
off	O
of	O
the	O
woofer	B-Device
.	O
</s>
<s>
Coaxial	B-Device
loudspeakers	I-Device
have	O
been	O
used	O
in	O
stage	O
monitors	O
,	O
giving	O
musicians	O
a	O
more	O
even	O
sound	O
field	O
because	O
of	O
the	O
single-source	O
characteristic	O
.	O
</s>
<s>
In	O
the	O
1980s	O
,	O
Professional	O
Audio	O
Systems	O
(	O
PAS	O
)	O
,	O
using	O
Time	O
Alignment	O
technology	O
from	O
Ed	O
Long	O
,	O
sold	O
the	O
popular	O
SW	O
series	O
of	O
compact	O
stage	O
wedges	O
,	O
offered	O
with	O
a	O
12	O
-	O
or	O
15-inch	O
woofer	B-Device
,	O
and	O
having	O
a	O
projecting	O
high-frequency	O
horn	B-Device
as	O
in	O
the	O
604	O
.	O
</s>
<s>
David	O
Gunness	O
and	O
Fulcrum	O
Acoustic	O
have	O
designed	O
coaxial	B-Device
loudspeakers	I-Device
beginning	O
in	O
2009	O
,	O
notably	O
collaborating	O
with	O
PreSonus	O
in	O
2013	O
to	O
create	O
the	O
self-powered	O
line	O
of	O
Sceptre	O
S6	O
and	O
S8	O
coaxial	O
studio	B-Device
monitors	I-Device
,	O
and	O
releasing	O
Fulcrum	O
's	O
own	O
FH15	O
full-range	O
horn-loaded	O
loudspeaker	O
series	O
in	O
2018	O
.	O
</s>
<s>
All	O
of	O
the	O
coaxial	O
Fulcrum	O
designs	O
use	O
digital	B-General_Concept
signal	I-General_Concept
processing	I-General_Concept
to	O
reduce	O
distortion	O
modes	O
.	O
</s>
<s>
Tannoy	O
has	O
produced	O
coaxial	B-Device
loudspeakers	I-Device
,	O
for	O
the	O
hi	O
fidelity	O
home	O
consumer	O
market	O
since	O
the	O
early	O
1950s	O
.	O
</s>
<s>
Their	O
"	O
Dual	B-Device
Concentric	I-Device
"	O
drivers	O
early	O
series	O
included	O
in	O
order	O
of	O
introduction	O
:	O
Tannoy	O
Blacks	O
,	O
Tannoy	O
Silvers	O
,	O
Tannoy	O
Reds	O
,	O
and	O
Tannoy	O
Golds	O
.	O
</s>
<s>
Jensen	O
introduced	O
several	O
coaxial	B-Device
speakers	I-Device
in	O
the	O
1950s	O
including	O
their	O
highly	O
regarded	O
triaxial	O
models	O
.	O
</s>
<s>
Several	O
other	O
manufacturers	O
introduced	O
coaxial	B-Device
speakers	I-Device
and	O
drivers	O
in	O
the	O
1950s	O
including	O
University	O
,	O
however	O
due	O
to	O
their	O
higher	O
cost	O
most	O
did	O
not	O
last	O
in	O
the	O
consumer	O
market	O
.	O
</s>
<s>
In	O
1988	O
,	O
KEF	O
introduced	O
an	O
extension	O
of	O
the	O
coaxial	B-Device
loudspeaker	I-Device
concept	O
.	O
</s>
<s>
This	O
was	O
made	O
possible	O
by	O
using	O
the	O
then	O
newly	O
affordable	O
powerful	O
yet	O
small	O
neodymium	O
magnets	O
for	O
the	O
tweeter	B-Device
making	O
the	O
whole	O
tweeter	B-Device
assembly	O
small	O
enough	O
,	O
magnet	O
included	O
,	O
to	O
fit	O
inside	O
the	O
woofer	B-Device
's	O
voice	O
coil	O
.	O
</s>
<s>
Other	O
home	O
audio	O
speaker	O
companies	O
making	O
coaxial	B-Device
speakers	I-Device
include	O
TAD	O
,	O
Cabasse	O
with	O
their	O
4-way	O
Concentric	O
QC-55	O
Driver	O
as	O
seen	O
in	O
their	O
flagship	O
model	O
-	O
La	O
Sphère	O
,	O
Hsu	O
,	O
Vandersteen	O
,	O
until	O
recently	O
Theil	O
,	O
and	O
a	O
budget	O
speaker	O
made	O
a	O
few	O
years	O
ago	O
by	O
Insignia	O
.	O
</s>
<s>
Coaxial	B-Device
speakers	I-Device
in	O
automobiles	O
are	O
2	O
-	O
or	O
3-way	O
loudspeakers	O
in	O
which	O
the	O
tweeter	B-Device
,	O
or	O
the	O
tweeter	B-Device
and	O
a	O
mid-range	O
driver	O
,	O
are	O
mounted	O
in	O
front	O
of	O
the	O
woofer	B-Device
,	O
partially	O
obscuring	O
it	O
.	O
</s>
<s>
The	O
low	O
frequency	O
sound	O
waves	O
from	O
the	O
woofer	B-Device
are	O
not	O
reduced	O
too	O
much	O
by	O
the	O
drivers	O
in	O
their	O
path	O
.	O
</s>
<s>
Without	O
time-alignment	O
correction	O
,	O
the	O
sound	O
from	O
the	O
tweeter	B-Device
may	O
arrive	O
slightly	O
before	O
the	O
sound	O
from	O
the	O
woofer	B-Device
;	O
this	O
misalignment	O
is	O
not	O
generally	O
addressed	O
in	O
automobile	O
sound	O
systems	O
.	O
</s>
