M&K Sound Professional Powered Subwoofer Operation Manual - page 8
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In some rooms, a corner location may excite resonance modes resulting in a muddy or boomy sound. In this situation, a
more central location along a wall, away from a corner may give better results. It’s a good idea to experiment with your
subwoofer location or locations. Try to find a placement or placements that provide an overall sound that is powerful and
well defined throughout the audio bandwidth, where no one bass note or notes overpower others.
Because the subwoofer generates so much sonic energy, its output may cause objects in and around the listening room to
vibrate. If this occurs in your room, you may need to damp the vibration of these objects.
One subwoofer is usually sufficient in a two-channel stereo system for the same reason that one subwoofer works well with
multi-channel systems. Our ear-brain hearing physiology is unable to locate the direction of low frequencies below
approximately 80 Hz. The directionality of low frequency sounds (bass drums, bass instruments, etc.) is determined by the
higher frequency overtones and harmonics that are reproduced by the satellite speakers.
Some people believe that we can determine directionality from frequencies down to 60 Hz. In any case, M&K Sound satellite
speakers are tuned to crossover to an M&K Sound subwoofer at 80 Hz. This is also the Dolby Laboratory and THX
specification.
No matter where you place your subwoofer, you must allow room for ventilation of its heat sink and back plate. The
subwoofer’s power amplifier is mounted on the back plate and it generates heat. Please observe the following:
1. Leave adequate clearance around the subwoofer’s heat sink. Do not cover it with
drapes or close it up in an unventilated cabinet.
2. Do not place the subwoofer near baseboard heaters or forced air heating outlets.
3. Do not use your subwoofer outdoors or in an overly humid environment.
4. Do not plug the subwoofer into an AC outlet until all system wiring is complete.
6. USE OF THE PHASE CONTROL
M&K Sound V8, V8 Movie V10 & V12 subwoofers feature a phase control variable from 0 to180 degrees. This control can
help you to fine tune the transition between sound sent to your main speakers and your subwoofer.
In order to optimize the integration of your subwoofer with your main speakers, you should perform a phase test.
This test will help you to achieve a seamless transition between your main speakers and subwoofer(s).
A phase test is helpful, because when satellite (or main) speakers are located in a different location from the subwoofer,
each speaker is located at a different distance to the listener. Even small differences in distance mean that the arrival times
of sound from the various speakers to the listener are also different. These time differences can cause phase anomalies,
which are destructive to the reproduction of sound in your room. Be sure to re-do this test if you move your speakers.
To begin, select something to play through your speakers that you are familiar with. A stereo CD is a good choice since
surround sound material with its complexity can make this test more difficult. While playing the CD through your left and
right ront speakers along with your subwoofer, listen to the mid-bass region (70 - 100 Hz) – that part of the audio spectrum
where instruments like bass and drums need both the satellites and subwoofer for accurate reproduction.
Adjust the phase control or switch from 0 degrees to 180 degrees. Note the difference between the two settings. If you hear
a tighter, more defined quality to the sound with better low bass reproduction with one of these options, then this is probably
the best setting. If you are using two or more subwoofers, perform this test with each subwoofer individually with the others
turned off.