MTX Audio TA7804 - Manual (Page 5)

3. Adjusting the Hi, 12dB / Low, 24dB Mono @ 40Hz–350Hz Variable X-over Frequency Controls –
• Setting for Subwoofers: First enable the electronic crossover by selecting the “ON” position of the X-OVER
switch, and then select the “L-PASS” (low pass) position on the L-PASS/H-PASS switch. Next, using “L-
PASS FREQ” you have control over what frequency you want your amp to start crossing over your signal.
By turning this control all the way counter-clockwise you are crossing the signal over at 40Hz (the range is
counter-clockwise 40Hz to clockwise 350Hz). This means that the amp will send the woofers frequencies from
20Hz to 40Hz and then start to taper down as the frequencies go over 40Hz (octave roll off). The industry
standard for low pass crossover point is right around 90Hz. However, by experimenting with the crossover
point (higher or lower) you will fi nd what sounds best in this install. This amp uses a 24 decibel per octave roll
off, which is pretty steep, or tapers off fairly quickly from the crossover point. This design complements both
the subwoofer and the mid to provide greater musical detail.
• Setting for Components and Separates: First enable the electronic crossover by selecting the “ON” position
of the X-OVER switch, and then select the “H-PASS” (high pass) position on the L-PASS/H-PASS switch. Next,
using “H-PASS FREQ” you have control over what frequency you want your amp to start crossing over your
signal. By turning this control all the way counter-clockwise you are crossing the signal over at 40Hz (the
range is counter-clockwise 40Hz to clockwise 350Hz). This means that the amp will send the components or
separates frequencies from 40Hz to 20kHz and then start to taper down as the frequencies go under 40Hz
(octave roll off). The industry standard for high pass setting or crossover point is around 120Hz. When the
amp is in HP setting and the crossover point is set to 120Hz, this means the amp is sending the speakers
frequencies from 120Hz to 20kHz. This crossover network allows the drivers to recreate the frequencies within
a precisely designed range so that the speakers do not become distorted by trying to reproduce frequencies
that they are physically unable to reproduce. This feature ensures that the components or separates do
not receive low bass notes. The 12dB/oct means the slope, or the amount of other frequencies that will
be affected, is fairly narrow. This design complements both the subwoofer and the mid to provide greater
musical detail.
• Setting for Full Range (No Crossover): To disable the electronic crossover, select the “OFF” position of the
X-OVER switch. This setting will allow the amplifi er to play all frequencies.
4. Adjusting The Variable ThunderEQ – Adjust the Pot clockwise to add the desired amount of bass boost. There
is a lot of boost available, 18dB of 40Hz, but begin with a low boost setting (around 3dB) and try to stay below
6dB whenever possible. Remember that for every 3dB of additional boost you dial in, you are asking the
amplifi er to double its power output for this boost region.
5. Adjusting the Active Resonance Control (A.R.C.) Feature – This feature will be needed when mounting
speakers lower in the door or in kick panels. Most vehicles have a natural peak that occurs at about 200Hz.
By turning the Pot, located on the top control panel, clockwise you CUT 200Hz up to 15dB. This allows you to
remove the unwanted peaks in your mids and highs that occur in most vehicles.
6. Remote Subwoofer Level Control (Remote Gain) – Let’s say the amplifi er’s gain is set at halfway. When the
remote subwoofer level control is plugged in, you have external control of the gain from zero to halfway. The
installation of this level control is NOT necessary to get full power from the amplifi er.
7. Prizm EFX – Now that you have completed adjusting all your amplifi er settings, you can set the lighting
effects to your personal taste.
• Selecting Colors: You can change the backlit colors simply by turning the dial labeled PRIZM COLOR, located
in the MTX PRIZM EFX section of the control panel, left or right. Starting at the left most position, the colors
range from RED to GREEN, BLUE, and then RED again. You can choose any color in between making the
combinations unlimited.
• Selecting the EFX Feature: You can switch Prizm EFX lighting to “pulsate” with the beat of the music. Simply
depress the button labeled PRIZM EFX located in the in the MTX PRIZM EFX section of the control panel to
turn this feature on or off.