Bose 901 Series II Owner's guide - Page 10

E.

CONNECTING

HEADPHONES

OR

CONVENTIONAL

SPEAKERS

It

is

important

to

remember

that

the

BOSE

901

Active

Equalizer

introduces

substantial

boost

in

the

range

below

100

Hz

and

above

3000

Hz

to

match

the

power

response

of

the

901

speakers.

This

means

that

if

other

speakers

or

headphones

are

played

while

the

Equalizer

is

in

the

circuit,

they

will

radiate

far

too

much

energy

in

the

low

bass

and

high

treble

ranges.

MORE

IMPORTANTLY,

HEADPHONES

OR

CONVENTIONAL

SPEAKERS

MAY

BE

DAMAGED

BY

PLAYING

WITH

THE

BOSE

901

EQUALIZER

CONNECTED

IN

THE

CIRCUIT.

For

these

reasons,

you

should

switch

the

Equalizer

out

of

the

circuit

by

placing

the

TAPE

MONITOR

switch

of

your

preamplifier,

integrated

amplifier,

or

receiver

to

the

OFF

(or

NORMAL)

position

when

play-

ing

your

system

through

headphones

or

a

pair

of

speakers

other

than

BOSE

901s.

IV.

GETTING

THE

MOST

OUT

OF

YOUR

901

SPEAKERS

A.

ADJUSTING

SPEAKER

PLACEMENT

There

are

3

reasons

you

might

wish

to

adjust

the

placement

of

your

901s:

to

change

the

frequency

response

of

the

system;

to

change

the

dispersion

of

sound

into

the

room;

or

to

change

the

appearance

or

usefulness

of

the

room.

The

primary

influence

of

speaker

placement

on

frequency

response

occurs

in

the

mid

-bass

region

(80.300

Hz).

This

frequency

range

includes

the

fundamental

tones

of

male

voice,

the

low

guitar

range,

string

bass,

cello,

trombone,

and

tympani.

Moving

the

vee

(the

back

of

the

901)

of

the

speakers

closer

to

the

wall

than

12

inches

will

boost

the

response

in

this

mid

-bass

range.

Do

not

move

the

back

of

the

speaker

any

closer

to

the

wall

than

8

inches.

Moving

the

vee

of

the

speakers

farther

from

the

wall

than

12

inches

will

decrease

the

response

in

the

mid

-bass

range.

Do

not

move

the

vee

more

than

18

inches

from

the

wall.

The

frequency

response

in

the

mid

-bass

range

can

also

be

modified

in

the

same

way

by

moving

the

speakers

closer

to

or

farther

from

the

floor,

the

ceiling,

or

the

side

walls.

In

all

cases,

DO

NOT

place

the

speakers

closer

than

18

inches

from

the

floor,

ceiling,

or

side

walls.

The

dispersion

of

sound

into

the

room

can

also

be

affected

by

moving

the

two

901

speaker

cabinets.

If

the

stereo

image

of

the

music

is

too

narrow,

simply

move

the

two

speakers

farther

apart.

It

is

recommended

that

the

speakers

be

placed

no

farther

apart

than

15

feet.

If

the

image

of

the

sound

is

too

broad,

or

if

there

appears

to

be

"too

much

space

in

the

middle,"

the

speakers

can

be

moved

closer

together.

It

is

recommended

that

the

speakers

be

moved

no

closer

together

than

4

feet.

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I

/

FIG.

7

10

Bose 901 Series II Owner's guide - Page 10

Getting, Speakers

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