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Input Section
Because of the wide range of head unit output configurations all ARC
Audio amplifiers have an adjustable input sensitivity or “Gain”. The gain
is not a volume or a power limiting control like a throttle. It makes the
amp more sensitive to input from the stereo. With the gain up the amp
will reach full output at a lower volume setting on the deck. At higher
gain settings the amp also becomes more sensitive to noise from the
car’s electrical system. Try to run the gain at the lowest setting possible
for you system.
There is no correct gain setting. Because speakers require different
power demands to reach the same output, the gains most often need
to be used to compensate for these differences. If you tried to set all the
gains at half way you
would probably find
the system didn’t
sound very good. Using
good judgment and
listening carefully to
each speaker is still the
best way to tune a
system.
Crossover Controls
A crossover is a device that removes unwanted frequencies from a speaker
or amplifier. A tweeter can easily be destroyed by bass notes if they are not
filtered out. Likewise a subwoofer will not sound natural if it is playing
midrange notes. A crossover removes these sounds from the speaker. As you
might guess, careful adjustment is need to
ensure that all the speakers are playing the
right sounds and that you are left with no
“holes” or low spots in the frequency
response.
Bass Boost
This amp has a fully adjustable bass boost. Both the frequency and the
level of the boost are adjustable. Start with a small increase in the level
control. Then “sweep” the frequency up and down. Listen carefully for an
improvement in the sound of the bass. If you do not hear any improve-
ment then the woofer does not need any boost.
Use Bass Boost carefully. The demands
on power output are tremendous. Try
to minimize the use by changing
woofer position or the enclosure size.
Subsonic Filter
A subsonic filter acts like a crossover but at very low frequencies. It
removes sound that is so low the speaker cannot reproduce it. You see
the cone moving but hear no sound. This can be very hard on your
woofer especially at high power. If
you are using a ported subwoofer
enclosure at high power you should
use a Subsonic Filter to limit cone
movement at very low frequencies.
Speaker outputs
This amplifier is a mono design. Meaning it has only 1 channel. It is
equipped with a single large block terminal for speaker connection.
Make this connection carefully and neatly. If the wires ever come in
contact with each other the amp will go into protection.
Know your total ohm load before you make any connections.
Note this amp is equipped with auto
ohm load sensing. It will adjust for the
ohm load “on the fly” anytime the load
changes. Do Not attempted to run
loads below 1 ohm.
