Jensen 900 Indicators and Controls, Power Indicator POWER, Input Level Control LEVEL, Bass Eq

POWER Amplifiers

Indicators and Controls

Power Indicator (POWER)

The power indicator provides a visual indication that the amplifier is turned on.

Input Level Control (LEVEL)

The input LEVEL control matches the output of your radio to the input of the amplifier. After the installation is complete, make sure the input level control on the amplifier is turned down all the way (counter-clockwise or all the way to the left). Play a tape or CD (make sure bass and treble settings or Bass EQ are flat) and turn the volume up slowly until you just start to hear distortion. Back the volume down just a bit. On the amplifier, slowly turn up the input level control (clockwise or to the right) until you just start to hear distortion, then back it down a bit. Now your radio and amplifier levels are matched.

BASS EQ

The Bass EQ is continuously adjustable from 0 to +12dB @ 45Hz. Adjusting the Bass Boost level allows different subwoofer/enclosure combinations to be equalized. Use this control to increase the level of low bass available from your subwoofer/enclosure combination. Ported and Band Pass enclosures should be limited to about +6dB to +9dB of boost. Sealed enclosures should be able to accept the full +12dB of boost, if necessary. The full +12dB of boost should be reserved for special applications since improper use of the Bass Boost could damage your subwoofers at high volumes.

Low Pass Filter (LPF)

The Low Pass Filter controls adjust the crossover point. Typical crossover is between 60Hz and 80Hz for ported and sealed enclosures. Bandpass boxes will typically use a higher crossover setting between 125Hz and 150Hz. Since musical tastes vary, you should play music that you would normally listen to in your vehicle, with the above settings as a starting point. If necessary, set the crossover by ear.

High Pass Filter (HPF)

The high pass filter will limit the low frequencies being transmitted to your speakers. This can be useful in number of situations. For example, if you selected the high pass filter and set the crossover to 40Hz, then you would have an infra-sonic (sub-sonic) filter at 40Hz, which would be useful with certain enclosure/subwoofer combinations that were tuned between 45Hz and 50Hz. Other uses might include limiting the low frequencies to smaller

speakers (6 1/2", 6 X 9", etc.) by adjusting the crossover to a higher setting (80–100Hz).

Crossover (X-OVER)

The Jensen Power series of amplifiers have built-in low-pass and high-pass crossover filters for bi-amplifying the system. Adjust the crossover to accommodate your chosen installation method. Select LPF (low pass filter) when the amplifier will be driving woofers or subwoofers. Choose FULL when crossover mode is not active and the amplifier is in “full range” mode. Select HPF (high pass filter) when the amplifier will be driving full-range or separate speakers, and you want to limit the “bass” being transferred to these speakers.

Mode Switch

Power 400 and 880

The 400 and 880 come equiped with a MONO/STEREO MODE switch. Use STEREO mode when you have a 2-channel input from the source unit. Use MONO mode when you have a single input from the source unit. See “Input Wiring” on page 8.

Power 760 and 920

The 760 and 920 come equiped with a 2/3/4 MODE switch and can be configured for three different input modes: 2 channel, 3 channel or 4 channel.

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