Bose 901 IV Series

B. ADJUSTING THE LOW AND HIGH FREQUENCY SOURCE
AND ROOM COMPENSATION CONTROLS
1 Select a weii'reco<Ued tanitliar recofd with a full orcheetfal
passage or a record with a large number of diverse musical
instruments that span the ertiire frequency range. Select a
recorded passage that has sustained music over several
seconds so you can observe the effects of the controle.
2. P reset the HIGH FREQUENCY Control m the center.
3. Move the LOW FREQUENCY Control baclr arxJ forth
several times ovsr the extremes of the contrors rartge and
carefully hstan to its effect. You will noilce a dramatic
char>ge in the basic luiiness or body of the sound without
char>ging ths deep bass Or midrange. Slar1ir>g with the corv
trol at the extreme leit. slowly move the Knob until the
balance ol the sound is rich and full, but without excessive
heaviness.
4. Next, replay the same passage again and move the HIGH
FREQUENCY Control Over the extremes of Ihe rartge
several times, hstervng lo Its efiecl. Starting with the corv
trol set at the extreme left, slowly rT>ove the knob until the
sound fills with in$trumer)iai detail clarity, and preserKe.
Note that since no room Is typical, it vnll be rare that the
center setting of both controls ts used. Accordingly. It Is
important lo realize that It is your adjustment of these
controls that will result In the speakers optimum perfor*
mance.
LOW FILTER CONTROL
The 901 Active Equalizer features a newty-de8igr>ed LOW
FILTER Control. The LOW FILTER Swrlch can be used to
reduce Ihe lowest two octaves of bass er>ergy without affec¬
ting the mid-bass response. This control is most useful In
removing record or turntable rumble.
leox
•01 IV eOUALIZBR CONTBQl ReSPONSE
C. SPEAKER PLACEMENT
Several options are possible regarding placement cf your 901
n your listening room. Shelving that is deep enough to provide
the necessary distances behind and to the side of the speake
system can be used Make certain the shelving is substantig
and not the same shelf used to hold your turntable, as pcssibi
acoustrc teedback can occur.
Many people choose the attractive pedestals avaliaPie wit
the 901 Series IV System. If you choose this method of suppor
instructions are provided with the pedestals for connectin
and mounting the speaker system, using the four predr Hie
holes (A) in the speaker bottom.
Another placement Idea is to suspend the speaker syster
from the ceiling (see Figure 1). This placement method i
particularly attractive if wall surfaces are interrupted by wir
dow$ or doorways or if floor placement ie difficult due t
furniture or the presence of children.