Crossover Adjustments; Level Setting - Soundstream USA 305 Owner's Manual And Installation Manual

CROSSOVER ADJUSTMENTS

In most car audio installations, there is a tendency for a "midbass boom."
Because of their interior dimensions, most cars will resonate or ring at these
midbass frequencies. If we design the system so there is less musical
information in this region, the final response is very smooth and natural
sounding.
Low Pass High Pass
Staggered Crossover
24 dB/octave low pass,
12 dB/octave high pass
FREQUENCY RESISTOR VALUE
53 Hz 30 K
73 Hz
22 K
89 Hz
18 K
107 Hz 15 K
145 Hz 11 K
195 Hz 8.2 K
286 Hz 5.6 K
485 Hz 3.3 K
800 Hz 2.0 K
NOTE: The following formula may be used to determine values in creating
"custom" resistor packs. The frequency is equal to 1,600,000 divided by the
individual resistor value, or 1,600,000 / R ohms = X Hz. To make a custom S.
I.P., use 4 identically valued resistors of 2% or tighter tolerance. See the
drawing of the S.I.P. for more information.
The USA•305 incorporates
staggered electronic crossover.
The high and low pass portions of
the crossover can be
independent of one another.
Below is a chart of S.I.P. values
which can be used for changing the
factory preset crossover points for
the subwoofer channel of
USA•305. The high pass channels
of this amplifier are not variable.
COLOR CODE
Green-Green
Green-White
Violet-Green
Violet-White
Example: 1,600,000 / 22,000 = 73 Hz
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INSTALLATION STEP 5
The input levels are adjusted by means of the input level controls located on
the front of the amplifier.
In the ideal situation, all components in the audio system reach maximum
undistorted output at the same time. The reason is because an amplifier will
a only make what comes into it bigger. So, if you send it a distorted signal from
the head unit, it is going to amplify distorted information. The same thing
holds true if an outboard processor or crossover begins to distort before you
set have maximum output from the amplifier. By setting all components to reach
clipping at the same time, you can maximize the output of your system.
Follow the below procedure for the quickest, easiest means of setting the
levels:
the
1. Turn the amp's input levels to minimum position (fully counter-
clockwise).
2. Set source unit volume to approximately 3/4 of full volume.
3. While playing dynamic source material, slowly increase the amplifier's
NOTE: Even though the S/N ratio with low output sources is better with the
Soundstream amplifiers than others, your best combination of output level
and Signal to Noise ratio will be achieved when the input levels are set
between 500 mV and 2.5 V
Installation with Plexiglass Bottom Plates
Plexiglass bottom plates are available for all USA amplifiers. They are
designed to enhance the cosmetics of virtually any installation by proudly
displaying the USA flag circuit board, and American made circuitry!
When installing a USA amplifier with a plexiglass bottom plate, try to
make certain that the amplifier receives adequate ventilation. You can do this
by mounting the amplifier in such a way that the heat sink fins are oriented
vertically. If the amplifier is to be mounted horizontally, a +12V fan can be

LEVEL SETTING

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