20mm t w eeter features, Crossover design, Speaker placement – Precision Power 2010 POWER CLASS COMPONENTS PC2.65C User Manual
Page 8

20mm T
w
eeter Features
Voice Coil &
Terminals
The coil is wound on a 20mm Kapton
former and sits entirely
in an unde
rhung gap
for 100% linearity and minimal distortion.
Diaphragm
We did not invent the
inverted dome, but w
e
wish we had. We chose an anodized
aluminum
inverted and self-s
uspended
diaphragm.
The dome is te
xtured for rigidity
and inverting the diaphragm yields more
control over sound dispersion.
Crossover Design
There are a few of ways to crossover a set of 3-way components
.
A basic 3-
way passiv
e
network would be the easiest. Some com-
panies s
e
ll a 2-way kit
with an “A
dd-A-Midbass” separate kit whic
h
combined r
equires 2 passive net
works. Or you can us
e all active
crossovers with an amplifier channel per each individual driver
.
While this allows the ultimate in
flexibility and tuning, it also re-
quires very skilled installers/tuners or damage can easily be done.
The crossover supplied with the
2-way and 3-way kits are one in
the same. This reduc
es cost and si
mplifies
installation. There is a
push-button switch to go from 2-
wa
y to 3-way application. Pretty
dang clever if we do say so ourselves!
In 2-way mode the crossover s
end a 12dB highpass
signal to the
20mm Tweeter at 4kHz, and a 12dB
lowpass signal to the 6.5”
Midbass driver at 4kHz as well.
When the button is switched to 3-
way, the 6.5” Midbass speaker wires need to move down to the
new location on the crossover to
make room for the 2.5” Midrange.
The Midrange section of the cr
ossover now changes
to a 400Hz
highpass - 4kHz lowpass, creati
ng a bandpass signal for the mi
d-
range with plenty of protection. The new Midbass section is a
400Hz lowpass for the 6.5” driver.
We chose all 12dB per octave roll-
off slopes which keep
s all drivers in phase with each other. Did you
know that 6db and 18dB crossovers
shift phase by 9
0
and 270 de-
grees? Not
cool! For further protection of the Tweeters
, some com-
panies us
e a PT
C capacitor which
is basically a heat activ
ated
switch. Some other c
o
mpanies
use
a bul
b
to absorb
excess power
during transient peaks
. We chose to use both for the ultimate protec-
tion for the Tweeter. All parts are t
op qualit
y as we believe that the
crossover is just as important as t
he rest of the speak
e
rs in generat-
ing audiophile quality sound reproduction.
Speaker Placement
The quest for the perfect soundstage has always been a great chal-
lenge. The ultimate goal is to get
the stage to sound as if you were
there live!
The perfect soundstage
would be at least ear lev
e
l or
higher, wider than the vehicle its
e
lf
and as far forward of the wind-
shield as possible. Many people do not
realize that it is very possible
to hear the soundstage “outside of
the vehicle” which means that the
musicians and singers can be percei
ved as being on a larger stage
than the dash. Much larger! In
a well designed, built
and tuned v
ehi-
cle, the members can be heard in
the middle of the hood and further
out than the edge of the fenders.
Some people install their components
in their doors while others want
them on top of the dash. Som
e
pe
ople s
tarted putting speak
e
rs in
kickpanels to minimize pat
hlength differences from one side of the car
to the other. Pathlength is the dist
ance from the speaker
to the ear or
microphone. Obvious
ly, if we ar
e in
the dr
iver seat, the driver s
ide
sounds louder. This is because sound
diminishes the further it gets
away from us. If we sat in the
mi
ddle of the car, both si
des would be
equally as loud and the st
age would be
dead center! But since t
h
at’s
not an option, speaker placement becom
es critical to get the stage as