Black Hydra HDA-4.90, User Manual

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ACOUSTIC SYSTEMS CONNECTION INPUTS
The input resistance of the amplifier is 48 k
Ω
, the input sensitivity is adjustable from 100 mV to 8 V, so
that the device is compatible with any sound source. Sensitivity adjustment is performed by turning the input
potentiometer to the right and left with the help of a screwdriver.
Brief recommendations for tuning the amplifier
1. Set the sensitivity of the amplifier to the minimum position
2. Connect the speakers
3. Start the head unit (sound source) with disabled equalizer / timbre, loudness, etc.
4. Smoothly increasing the volume on the head unit, check for absence of distortions approximately up
to 2/3 of the maximum volume level.
5. Turn on the high pass filter for the front speakers and set the cutoff frequency in the range of 40-80
hertz (depending on the capabilities of the speakers)
6. Smoothly increasing the sensitivity of the amplifier to achieve a comfortable volume, in the absence
of audible distortions, at 2/3 of the maximum volume value.
7. Smoothly changing (increasing / decreasing) the cutoff frequency of the high pass filter to achieve a
comfortable sound with maximum bass effect, with no audible distortions.
8. Enable custom / factory settings for equalizer, timbre, loudness and time delays (DSP) and check
for no audible distortions in this mode. If there are distortions, go back to steps 5.6.7 and repeat the setting
adjustment.
Note. Depending on the music genres and the phonogram specifications, different settings results can
be obtained.
Both pairs of amplifier channels can be used in the configuration of the mono bridged mode when using
a Y-splitter RCA cable.
To ease the installation of the sound system with per channel amplification, the amplifier has an active
crossover for each pair of channels, an adjustable low-pass filter (LPF) and a high-pass filter (HPF), which can
also be easily turned off by means of buttons on the side control panel. Two potentiometers provide smooth
adjustment of crossover filters.