REVELL Concerta B1, Руководство пользователя

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10
B1 Subwoofer
Owner’s Manual
SUBWOOFER LEVEL (VOLUME) CONTROL
Provides basic volume adjustment for the subwoofer. Begin with this
control set to the nominal “12 o’clock” position.
LOW-PASS FREQUENCY CONTROL
Figure 15: Rear-panel controls and connectors
Adjusts the variable 50Hz – 150Hz low-pass crossover, which
determines the highest frequency at which the B1 reproduces sounds.
Set the crossover to a lower frequency setting, between 50Hz and
100Hz, when using larger main loudspeakers that can comfortably
reproduce some low-frequency sound.
With a lower frequency setting, the B1 subwoofer concentrates on
reproducing the deep bass required by contemporary music and film
soundtracks. Set the crossover to a higher frequency, between 100Hz
and 150Hz, for smaller bookshelf loudspeakers that do not extend to the
lower bass frequencies.
If the frequency control is set too high, the bass sounds “boomy” and
can overpower the overall sound of the listening room. If the frequency
control is set too low, some low frequency sound may be difficult to
hear, or may be absent altogether.
This control has no effect when using the Sub In input or if the Low-Pass
Switch, shown in Figure 17, is set to Off (Normal) because in both cases
the receiver/processor sets the crossover frequency.
NOTE: This control does not limit the frequency range of the
main speakers in the system. The objective of adjusting the
Low-Pass Frequency control is to ensure that all frequencies
are reproduced while minimizing any overlap between the
subwoofers and the main speakers. Having both the subwoofer
and main speakers reproduce the same frequencies should
be avoided, as it results in very irregular response, since some
frequencies are reinforced when they happen to be in phase
while others are canceled because they are out of phase.
PHASE SWITCH
Figure 16: Phase switch
Compensates for the absolute phase of the subwoofer’s output relative
to the front speakers. Some associated electronics can invert the
absolute phase. Use this switch to correct such occurrences. Proper
phase adjustment can also depend on variables such as subwoofer
placement and listener position. Use this switch, shown in Figure 16, to
maximize bass output at the primary listening position.
• Select the 0° setting to set the B1 acoustic output in phase (0
degrees) with the input.
• Select the 180° setting to invert the B1 acoustic output (180 degrees)
relative to the input.