TURN-ON LEAD
The e1800D uses a conventional +12V remote turn-on lead, typically controlled by the source unit's remote turn-on output.The amplifier will turn on when +12V is present at its “Remote” input and turn off when +12V is switched off. If a source unit does not have a dedicated remote turn-on output, the amplifier’s turn-on lead can be connected to +12V via a switch that derives power from an ignition-switched circuit.
The e1800D's “Remote” turn-on connector is designed to accept 18 AWG – 12 AWG wire.To connect the remote turn-on wire to the amplifier, first back out the set screw on the top of the terminal block, using the supplied 2.5 mm hex wrench. Strip 1/2 inch (12mm) of wire and insert the bare wire into the terminal block, seating it firmly so that no bare wire is exposed. While holding the wire in the terminal, tighten the set screw firmly, taking care not to strip the head of the screw and making sure that the wire is firmly gripped by the set screw.
INPUT SECTION
The e1800D has one input section with two distinct input connection options.
1)A pair of traditional RCA type connections designed to accept input from source units with line level outputs.
2)A four-pin connector designed to accept input from amplified sources such as factory source units or source units not equipped with line level outputs.
You may run a stereo or a mono signal into the inputs of the amplifier.The amplifier's input section automatically sums stereo signals to mono for the internal amplifier section.
!
IMPORTANT
If you plan to use the “Pre-Outs” to feed a stereo amplifier, you must connect a stereo signal to the input of the amplifier. A mono signal into the amplifier will result in a mono signal out of the preamp output. (It's a great amplifier, but it doesn't do magic).
The amplifier will operate with only one input connection (left or right), but will require an increase in input sensitivity to overcome the loss of signal. If a mono input signal is to be run, we recommend that you use a “Y-adaptor” to split the mono signal into both inputs of the amplifier.
AMPLIFIER CONTROLS
Input Sensitivity
This control, labeled “Input Sens.”, can be used to match the source unit's output voltage to the input stage of the e1800D for maximum clean output. Rotating the control clockwise will result in higher sensitivity (louder for a given input voltage). Rotating the control counter-clockwise will result in lower sensitivity (quieter for a given input voltage.)
To properly set the amplifier for maximum clean output, please refer to Appendix A (page 10). After using this procedure, you can then adjust the “Input Sens.” level downward if this is required to achieve the desired system balance.
Do not increase any “Input Sens.” setting for any channel(s) of any amplifier in the system beyond the maximum level established during the procedure outlined in Appendix A (page 10). Doing so will result in audible distortion and possible speaker damage.
Filter Controls
Most speakers are not designed to reproduce the full range of frequencies audible by the human ear. For this reason, most speaker systems are comprised of multiple speakers, each dedicated to reproducing a specific frequency range. Filters are used to select which frequency range is sent to each section of a speaker system.The division of frequency ranges to different speakers can be done with passive filters (coils and/or capacitors between the amplifier outputs and the speakers),
which are acceptable and commonly used for filtering between mids and tweeters. Filtering between subwoofer systems and satellite speaker systems is best done with active filters, which cut off frequency content at the input to the amplifier. Active filters are more stable than passive filters and do not introduce extraneous resistance, which can degrade subwoofer performance.
The active filter built into the e1800D can be used to eliminate potentially harmful and/or undesired frequencies from making their way through the amplifier section to the subwoofer(s). This serves to improve tonal balance and to avoid distortion and possible speaker failure. Correct use of this filter can substantially increase the longevity and fidelity of your audio system.
The e1800D employs a sophisticated, variable, low-pass active filter for its internal channel.This feature is designed to attenuate frequencies above its filter frequency, so that the system's subwoofers do not reproduce any audible midrange content.
1)Filter Operation: The low-pass filter in the e1800D is fully variable between 40 Hz and 200 Hz via the “Filter Freq.” control knob and features the ability to select between a moderate “12dB” per octave or a steep “24dB” per octave slope via the
“Mode/Slope” switch.
Depending on the subwoofer system and the vehicle, different slopes may be required to produce a smooth transition to the mid-bass speakers in the system. Experiment to find the slope which best matches the acoustic requirements of your system.
Hint: A trunk mounted sub whose output has to "fight" through a rear deck or a back seat often benefits from the 12 dB/octave slope which lets more upper bass content pass through. A sub that
fires directly into the listening environment is more likely to benefit from a 24 dB/octave slope.
The above hint is not “set-in-stone”…
You should always listen to the system carefully to determine the best choice as vehicle acoustics and other factors play a big role in choosing the most appropriate filter slope.
2)Precise Frequency Selection: The filter frequency markings on the front panel of the amplifier are for reference purposes and are generally accurate to within 1/3 octave or better. If you would like to select the filter frequency with a higher level of precision, consult Appendix B (page 11) of this manual.This chart gives you a more accurate frequency for each of the forty detented positions of the frequency selection control.This method can be very useful if the amplifier is mounted in a location where you can’t see the front panel markings easily.
3)Defeating the Amplifier Filter: The Low- Pass filter can also be defeated completely, by switching the “Mode/Slope” switch to the “Off”
position.This is useful if you are using an external active crossover in the system. Keep in mind that turning the internal crossover off also defeats the “Advanced Bass Control” section processing (see page 9 for details). With the internal crossover turned off, the e1800D’s upper frequency response limit is 250 Hz, due to its bass-specific Class D design.
BASS BOOST CONTROLS
1)Bass Boost: This switch allows the user to activate a 6 dB boost centered at 48 Hz.The “Filter Mode” switch in the “Channel 1 & 2” section must be in the “LP” position for the bass boost to
be functional.
