JL Audio M800/8-24V, Руководство пользователя

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8 | JL Audio - M800/8-24V Owner’s Manual
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 mid-range speakers 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 each channel section
of the M800/8-24V can be used to eliminate
potentially harmful and/or undesired frequencies
from making their way through the amplifier
sections to the speaker(s). This serves to improve
tonal balance and to avoid distortion and possible
speaker failure. Correct use of these filters can
substantially increase the longevity and fidelity of
your audio system.
Remote
Level
Mode
All | 5- 8 | 7&8
Input Mode
2 Ch. | 4 Ch. | 8 Ch.
CH. 7
(L)
CH. 8
(R)
CH. 7 & 8
Filter Mode
Filter Freq. (Hz)
Input
Sens.
Off | HP | LP
CH. 5
(L)
CH. 6
(R)
CH. 3
(L)
CH. 4
(R)
CH. 1
(L)
CH. 1 & 2 CH. 3 & 4 CH. 5 & 6
CH. 2
(R)
Filter Mode
Filter Freq. (Hz)
Input
Sens.
Off | HP | LP
Filter Mode
Filter Freq. (Hz)
Input
Sens.
Off | HP | LP
Filter Mode
Filter Freq. (Hz)
Input
Sens.
Off | HP | LP
CH. 1
CH. 2
CH. 3
CH. 4
CH. 5
CH. 6
(L)
(R)
CH. 7
CH. 8
INPUT SEC
TION
+24 VDC Ground Remote
2 Ch. Input 1 feeds CH. 1, CH. 3, CH. 5 & CH. 7
Input 2 feeds CH. 2, CH. 4, CH. 6 & CH. 8
4 Ch. Input 1 feeds CH. 1 & CH. 3
Input 2 feeds CH. 2 & CH. 4
Input 5 feeds CH. 5 & CH. 7
Input 6 feeds CH. 6 & CH. 8
8 Ch. Each input feeds its
corresponding output channel
INPUT MODES:
Marine 8 Channel Amplifier
NOT FOR USE IN 12V SYSTEMS!
-24V
1) “Filter Mode” Control: The M800/8-24V
employs a 12dB per octave filter for each
pair of channels. Each of these filters can be
configured independently into one of two filter
types or defeated completely by way of the
three-position “Filter Mode” switches:
“Off”: Defeats the filter completely, allowing
the full range of frequencies present at the inputs
to feed the amplifier. This is useful for systems
utilizing outboard active crossovers or requiring
full-range reproduction from one or more of the
M800/8-24V’s channel pairs.
“LP” (Low-Pass): Configures the filter to
attenuate frequencies above the selected filter
frequency at a rate of 12 dB per octave. This is
useful for connection of subwoofer(s) to one
or more of the M800/8-24V’s channel pairs in a
bi-amplified system.
“HP” (High-Pass): Configures the filter to
attenuate frequencies below the selected filter
frequency at a rate of 12 dB per octave. This is
useful for connection of component speakers to
one or more of the M800/8-24V’s channel pairs in
a bi-amplified system.
2) “Filter Freq. (Hz)” The filter frequency
markings surrounding this rotary control
are for reference purposes and are generally
accurate to within 1/3 octave or better. If you
would like to select the filter cutoff frequency
with a higher level of precision, consult the
chart in Appendix B (page 15).
Tuning Hint: If you are using the M800/8-24V
to drive a subwoofer system (“LP” mode), a
component satellite speaker system (“HP” mode)
or both, 80 Hz is a good baseline “Filter Freq.
(Hz)” setting. After properly adjusting the “Input
Sens.”, as outlined in Appendix A (page 14), you
can fine tune the “Filter Freq. (Hz)” control to
achieve the desired system frequency response.