6. SATELLITE/SUBWOOFER PHASING TEST
In any system using a subwoofer separate from satellite speakers, a phasing test must be performed to insure good
bass blending. This test insures optimum sound in the critical bass frequencies where your subwoofer and satellite
speakers overlap.
SATELLITE/SUBWOOFER SYSTEM
If you own an M&K powered subwoofer, see its owner's manual for the correct procedure for matching phase
between the satellites and subwoofer. Its "SUBWOOFER PHASE" switch makes this important test very easy. If your
subwoofer does not have a "SUBWOOFER PHASE" switch, follow this procedure:
Play a familiar CD, LP, or tape with steady, consistent bass content through your system. Listen carefully to the "mid-
bass" region of 75 - 125 Hz. This is the part of the spectrum where electric or string basses and drums predominate.
Then, reverse the Positive and Negative speaker inputs on the back of BOTH satellite speakers.
You can do this at the back of both satellite speakers, or at the subwoofer's "TO SPEAKERS" terminals (certain
models only), but never at both locations. The lead that was on the Positive (+) terminal should be switched to the
Negative (—) terminal, and vice versa.
Now listen to the same musical passage as you did earlier, concentrating on the mid-bass region. If you hear less
bass, the original connections were correct. If you hear more bass, the new connections are correct.
You need to perform this test because when satellite speakers are located separate from a subwoofer, each
speaker is at a different distance from your ear. In some cases, the difference will be just enough so that the output from
the subwoofer arrives out of phase with the output of the satellites. When this happens, that critical mid-bass is
actually cancelled. You should re-do this test any time you move your speakers.
7. SPEAKER DAMAGE & HOW TO AVOID IT
An important factor to consider with any loudspeaker system is the potential for speaker damage. Even though your
speakers have extremely high power handling ability, they still can be damaged by relatively low powered amplifiers.
While very few M&K satellites are actually returned for service, the vast majority of those returned are not for
manufacturing defects. Instead, they are returned because they have been overdriven, almost always because the
amplifier or receiver used was driven into clipping distortion. This damage is considered abuse, and is not necessarily
covered under warranty.
This clipping distortion occurs when the demands of the music are greater than the amplifier's available power. It
can occur at 20 watts with a small amplifier, or at 400 watts with a large amplifier. Regardless, when this happens, the
amplifier's output waveform (which usually looks like a smooth arc) is "clipped" off, exhibiting a flat top instead of the arc.
This flat top contains multiples of the original amplified frequencies, sometimes at higher levels than the original
signal itself. For tweeters, this can be very damaging, as this distortion is well above the audible range, where you will
be unable to hear it, and where the tweeter is more vulnerable to damage.
When an amplifier clips, its sound becomes harsh and grating, and a break-up is often audible in the bass
frequencies. It will become uncomfortable to listen to, compared to a slightly lower volume level. When you are
listening at high volume levels, be aware of the onset of clipping distortion, and turn the volume down slightly if the sound
takes on the character described above.
When tone controls or equalizers are used to boost frequencies, the problem occurs much more rapidly. Even a
small boost of low or high frequencies can easily double the power requirement and lead to amplifier clipping at
moderate levels. Therefore, you should use your tone controls judiciously, avoiding extreme boosts of the bass and
treble controls, especially when you are listening at high volume levels.
MAIN SATELLITE SPEAKER
5
