Samson dB1500a - Manual (Page 10)

Operating the dB1500a and dB1800a
Level Control
The level control is used to adjust the
amount of volume from the dB1500a
or dB1800a subwoofer. In addition,
the Level control will also control the
output volume of the high-passed
outputs. Therefore, if you are using
the dB1500a or dB1800a without using
the high-passed outputs (for example,
when the dB1500a or dB1800a are
connected to an external crossover)
the Level control adjusts the low
frequency output of the dB1500a or
dB1800a. If you are using the dB1500a
or dB1800a’s internal electronic cross-
over to run satellite speakers, then the
Level control will adjust the overall
system volume.
Sweep
The Sweep control selects the upper range cutoff frequency of the dB1500a and dB1800a’s internal electronic crossover.
The dB1500a and dB1800a’s crossover provides a 12dB per octave Linkwisz- Riley filter curve. The Sweep limits the high
frequency that the dB1500a and dB1800a will reproduce, and at the same time, the high-passed output tracks the select-
ed crossover frequency as the lower limit frequency.
Stereo / Mono Switch
The Stereo/ Mono switch selects either stereo or mono bass operation. When set to MONO, the dB1500a and dB1800a
will combine, or sum, the left and right signals and send a mono signal to the amplifier of the dB1500a and dB1800a. In
this mode, the original stereo signal is passed through the left and right outputs only now the stereo signal is filtered at
the frequency set by the Sweep control. In Stereo mode, the low frequency signal is not summed, and you can choose
either the left or right input accordingly for each side of the system.
The In and The Outs
The dB1500a and dB1800a features electronically balanced inputs and outputs so that any possible HUM problems are
greatly reduced when interfacing to other equipment. XLR connectors with industry standard pin- outs are used for easy
interface from mixer and other professional audio gear. A detailed wiring diagram can be found in the section "dB1500a
and dB1800a Connections" on page 11 of this manual.
The dB1500a and dB1800a’s control panels provide the connections and user interface to the dB1500a and dB1800a’s
internal electronic crossover and power amplifier section. The internal amplifier is a 1000 Watt amplifier capable of pro-
ducing incredible bass output while running super cool. The dB1500a and dB1800a employ an electronic crossover that
adjusts the high frequency cutoff point for the subwoofer, and also, a high passed output for your satellite speakers. You
will achieve a tremendous benefit in sound quality by running your satellite speakers from the dB1500a and dB1800a’s
High-Pass outputs. The reason for this is that when your satellite speaker receives the filtered output from the dB1500a
and dB1800a, it will no longer be looking at the frequencies below the crossover point. Let’s say your satellite speaker
has a natural frequency roll-off at 70 Hz, and you are sending full range signal (as low as 20Hz) to the satellite amplifier
and speaker. Even though the speaker can only reproduce 70Hz and up, the amplifier is still outputting 20-70Hz, which is
wasted power and essentially turns into heat. By using the dB1500a and dB1800a’s High-Pass output, the satellite ampli-
fier and speaker never see the frequencies lower than what’s set by the Sweep frequency. This means you’ll have more
power dedicated to the frequencies you want the satellites to deliver, resulting in a much cleaner sound with more head-
room.
dB1500a and dB1800a CONTROL PANEL
ENGLISH
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