35Hz Level Control - MartinLogan Speaker User Manual

35Hz Level Control

After you have determined the speaker position and pri-
mary listening position (see pages 11–12) you will want to
adjust the 35Hz level control
On the rear of the Spire is a knob that control the 35Hz
frequency responses by ±10db. MartinLogan engineers
have found this frequency area (30–50Hz) to be problem-
atic. Low frequencies tend to react to a room environment
by creating nodes (boomy and unnatural bass) or nulls
(nonexistent bass). By adjusting the 35Hz level knob you
can 'dial out' undesirable nodes or nulls and create a bal-
anced and seamless presentation.
To help find the optimal setting for your room, play mate-
rial with (which you are familiar) with low frequency
information (such as a drum or a pipe organ). When
adjusting the 35Hz level we recommend doing so with
two or three people—one located at the listening position
and one or two people at the controls.
1 Start with the 35Hz level knob set to 0dB. The person at
the listening position needs to become familiar with the
sound at this setting. Remember, only the person in the
listening position should judge the bass integration. Nodes
and nulls change dramatically throughout every location
in a room. A person adjusting the controls on the speaker
will experience an entirely different bass performance
than a person sitting in the listening position.
10 Controls and Connection
2 Adjust the 35Hz level knob by +10dB. In most cases the
bass will sound boomy and unnatural. Return the setting
to 0dB and listen to the speaker again for a moment.
Next, adjust the 35Hz knob by –10dB. In most cases the
bass will sound thin and nonexistent. Return the setting
to 0dB and listen again for a moment.
Now you have an idea of the control you have over
the 35Hz output. If you feel the bass is too boomy
at 0dB, adjust towards the negative settings. If it is
to thin at 0dB, adjust toward the positive settings.
Repeat this procedure using increasingly smaller
amounts (8dB, 6dB, 4dB, etc.) until you find a setting
where the low bass sounds balanced—remember
to return the knob to 0dB and listen for a moment
between each adjustment. Once you've found the best
sounding setting for your room, make a note of the setting.
Remember—due to the unpredictabililty of every listening
room experimentation is essential when setting up
a loudspeaker. It may take several attempts to find a
combination of control settings, speaker positions, and
listening position that is ideal for you and your listening
preferences. If you still hear anomalies, you may need to
experiment with speaker placement or the location of the
listening position—sometimes even the subtlest adjust-
ments will make huge changes!