Bose 301 - Manual (Page 9)

The Direct Energy Control has been carefully designed to provide
the optimum performance of the Model 301 under a wide range of
listening conditions. This control primarily affects the spatial distri­
bution of high frequencies above 5 kHz. At distances close to the
loudspeaker, the effect of the control on high frequency energy is
very large, reaching 15 dB at 15 kHz. However, the effect decreases,
becoming more subtle, with increasing distance from the speaker and
will be less noticeable in larger rooms, where the listener is prin­
cipally in the reverberant field.
Under most listening conditions, critical listeners will find that the
Direct Energy Control provides a significant aid in optimizing the
performance of the Model 301.
Please note that the numbers which appear in Diagram 6 are for
reference only and do not appear on your speaker system. They are
there to help you understand the positioning required for optimum
performance in your listening environment. In the diagram, the left
speaker, when starting from the top marking, is rotated
clockwise
for increasingly high numbers. The right speaker is rotated counter­
clockwise for the same increase in reference numbers.
The following guidelines should be followed;
POSITIONS 1 AND 2 These positions provide the maximum direct
sound energy at high frequencies. For horizontal placement they
are used to establish high frequency balance if side reflecting walls
are not present or are covered with sound absorbing material.
These positions provide less stereo spread than higher numbers
and will be preferred by some listeners for reproduction of soloists
and small ensembles. Use positions 1 and 2 for vertical placement
if the speaker is placed higher than 4 feet.
POSITION 3 This is the normal setting of the Direct Energy Con­
trol. This position is used for horizontal placement when a side re­
flecting wall is located near the side of the speaker, as shown in
Diagram 2. page 6. Under this condition, most of the high frequency
C. Adjustment of the Direct Energy Control
ROTATE CLOCKWISE FOR
MAXIMUM REFLECTED SOUND
ROTATE COUNTER CLOCKWISE
FOR MAXIMUM REFLECTED SOUND
DIAGRAM 6
POSITIONS OF THE
DIRECT ENERGY CONTROL
energy from the tweeter will be reflected by the side wall into the
center of the room. Use position 3 for vertical placement if the
speaker Is placed lower than 4 feet, or within 2 feet of a hard ceiling.
POSITIONS 4 AND 5 These positions provide minimum direct
sound energy at high frequencies and are used for horizontal place­
ment if a reflecting side wall is present. Operation in Positions 4
and 5 will provide very spacious stereo reproduction, especially
suited for large ensembles such as an orchestra or a chorus.
D. Room Acoustics
The sound quality of loudspeakers depends on many environmen­
tal factors other than speaker placement, such as the size, shape and
construction of the room, and the amount and type of furniture,
rugs and draperies present. A lack of bass response frequently
may be attributed to walls of thin panel construction, large openings
(e.g., doorways), or excessive window glass, which allow low fre­
quencies to pass through rather than reflecting them Into the room.
The overly bright sound of acoustically “live" rooms (e.g., those with