Genelec 8010A Operating Manual page 29

Phase Alignment Using Test
Equipment
Feed in the test signal to LEFT IN or RIGHT
IN of the subwoofer. Place the microphone
at the listening position. Using a real-time
analyser or other frequency response
measurement system, adjust the sensitiv-
ity of the subwoofer until the frequencies
below and above 85 Hz are reproduced
at equal level. Then, adjust the phase
switches for the maximum dip of at least
-6 dB at the crossover frequency (85 Hz).
Invert the -180° switch to the opposite
setting. The phase is now aligned and
the measurement should show a smooth
response around 85 Hz.
Setting the Bass Roll-Off
The acoustic response of the subwoofer
can compensate the room character-
istics. To adjust the subwoofer use the
''Bass Roll-Off' switches located on the
connector panel. These offer attenuation
levels of -2, -4, and -6 dB at the lowest
subwoofer output frequencies. Table 1
provides suggestions for Bass Roll-Off
switch settings. Flat anechoic response
is obtained when both roll-off switches
are set to "OFF".
Safety Considerations
Genelec 7040A subwoofer has been
designed in accordance with interna-
tional safety standards. However, to
ensure safe operation and maintain the
unit in safe operating condition, the fol-
lowing warnings and cautions must be
observed:
• Do not expose the subwoofer to water
or moisture. Do not place any objects
filled with liquid, such as vases on the
subwoofer or near it.
• Servicing and adjustment must only be
performed by authorized Genelec ser-
vice personnel.
• Opening the amplifier unit is strictly
prohibited except by authorized ser-
vice personnel.
• Always use a mains power connection
with protective earth terminal. In case
of fault, failing to do this may lead to
personal injury.
Warning!
This equipment is capable of delivering
sound pressure levels in excess of 85
dB, which may cause permanent hearing
damage.
Maintenance
No user serviceable parts are inside the
amplifier unit. Any maintenance of the
unit must only be performed by Genelec
authorized service personnel.
Guarantee
This product is supplied with a two year
guarantee against manufacturing faults or
defects that might alter the performance.
The guarantee can be extended to five
years by registering the product on www.
genelec.com. Refer to the supplier for full
sales and guarantee terms.
Compliance to FCC rules
This device complies with part 15 of the
FCC Rules. Operation is subject to the fol-
lowing conditions:
• This device may not cause harmful
interference, and this device must
accept any interference received,
including interference that may cause
undesired operation.
Note: This equipment has been tested and
found to comply with the limits for a Class
B digital device, pursuant to part 15 of
the FCC Rules. These limits are designed
to provide reasonable protection against
harmful interference in a residential instal-
lation. This equipment generates, uses and
can radiate radio frequency energy and, if
not installed and used in accordance with
the instructions, may cause harmful inter-
ference to radio communications. How-
ever, there is no guarantee that interference
will not occur in a particular installation. If
this equipment does cause harmful inter-
ference to radio or television reception,
which can be determined by turning the
equipment off and on, the user is encour-
aged to try to correct the interference by
one or more of the following measures:
• Reorient or relocate the receiving
antenna.
• Increase the separation between the
equipment and receiver.
Frequency response 7040A 25.3.15
+100
+80
+60
+40
+20
+0
10
20 30 50 100 200
Figure 6. The free field frequency
response of the 7040A subwoofer at
different Bass Roll-Off settings
Harmonic distortion 7040A 25.3.15
+100
+80
Fundamental
frequency
+60
2nd harmonic
+40
+20
3rd harmonic
+0
10
20 30 50 200
100
Figure 7. The curves above show the
harmonic distortion analysis of the
7040A in free field. In half space the SPL
will be 6 dB higher.
• Connect the equipment into an outlet
on a circuit different from that to which
the receiver is connected.
• Consult the dealer or an experienced
radio/TV technician for help.
Modifications not expressly approved by
the manufacturer could void the user's
authority to operate the equipment under
FCC rules.
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