Niles PERFORMANCE PR5 Installation & Operation Manual Download Page 5

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The Boundary Effect

Corners can affect the bass response of

the speaker powerfully! This is called the

boundary effect. You will emphasize par-

ticular bass frequencies and cancel out

other bass frequencies when you place

speakers close to the wall/ceiling bound-

ary or a corner wall boundary. This can

make the speaker sound excessively

boomy and inaccurate to some listeners,

while to others it just seems like more

bass sound. A good rule of thumb is if

you always listen to your current pair of

speakers with the bass turned up, you’ll

enjoy corner placement. If you keep your

tone controls at neutral, try to keep the

speakers at least two or three feet from

the boundaries of the room.

Placement for Varying Listening
Positions

If you want the freedom to sit anywhere

in a room facing any direction, and/or

find that you prefer the “all around you”

sound of some car stereos to a conven-

tional “sound stage” facing you, consider

the speaker placement techniques profes-

sional installers use in restaurants and

bars. They place speakers in an array

around the listening area, so that the

music is always surrounding you, regard-

less of the direction you face.
The rule of thumb is to add one pair of

speakers for every 100 to 200 square feet

of listening area. Curiously, this is not

so that you can play the music louder,

but so that you can play it softer! When

you have only one pair of speakers in

a large room you will notice that when

the sound is perfect in one part of the

room, it is too loud near the speakers. By

placing more than one pair in the room

you will avoid these “hot spots” of loud

sound and you will create more sonic

ambiance while maintaining clarity and a

rich sound everywhere.

You can make listener position still

less critical by using mono rather than

stereo. This can be difficult to achieve

with normal stereo amplifiers. However,

Niles manufactures Systems Integration

Amplifiers

which enable one room to

be wired in stereo while other rooms are

wired in mono! Consult your local Niles

dealer for more information.
In smaller rooms or rooms that are infre-

quently used, you typically can’t justify

the expense of more than two speakers.

Try to bracket the room with the two

speakers. Diagonal placement is a very

effective way to stretch the coverage pat-

tern of two speakers. You can also com-

promise between direct sound (for detail

and clarity) and reflected sound (the

ambient or “all around you” effect). By

trying to place the speakers so that they

create as much reflected sound as pos-

sible you emphasize the ambient effect.

They can be up high in the wall or even

down low at power outlet height , in

the ceiling, near corners, or directed at

reflective objects and walls. The more

reflected sound there is in the room the

stronger the ambient effect at low vol-

umes. You should use moderation, how-

ever, otherwise the compromise becomes

too one sided and at high volumes, the

sound will be blurred and less distinct.

Placement for Rear Home Theater
Applications

In a home theater, the goal is to repro-

duce the experience of a great movie the-

ater in our homes. The biggest difference

between the two is the rear or surround

speaker array in a commercial theater.

Here, it is not uncommon to see twenty

or thirty speakers around the audience.

This huge array of speakers assures that

you will feel completely surrounded by

the ambient soundtrack of the movie.

Film makers try to use the “surround”

Speaker Placement

soundtrack to envelope you in the envi-

ronment on screen. They will place back-

ground music, rain sounds, traffic noise,

etc. on the “surround” soundtrack. In a

home with a single pair of speakers it is

easy for the jungle sounds to sound like

they are “in the middle of your head” just

like headphones!

A single pair of PR loudspeakers, prop-
erly placed, can create a very convincing
simulation of an array of speakers. If you
place them near a hard reflecting surface
you can make one pair of speakers sound
like several. Create as many reflections
as possible by mounting the speaker up
high in the wall so that the ceiling will act
as a powerful reflector. If you place the
speakers near a corner, wash the sound
down a wall from a ceiling location, or
mount the speakers as far away as you
can from the listening area, more reflec-
tions will occur. However, all of these
placement techniques require that you
work your surround sound amplifier chan-
nels harder. If the surround sound system
you are using has a small five or ten watt
amplifier for the rear speakers, stay within

five to eight feet of the listening location.
If you are using a 25 to 50 watt amplifier
you can mount the speakers 10 to 15 feet
away from the listening location and still
achieve reasonably high volume levels.
Of course, the best way to emulate the

sound of multiple speakers is to use mul-

tiple speakers. In large or unusually shaped

rooms this might be the only way to

achieve a good effect. If you like to listen

to music surround modes which emulate

concert hall acoustics, more than two sur-

round speakers will prove extraordinarily

effective. With Niles PR loudspeakers it is

easy to add another pair without affecting

the decor of the room. However, you will

need to use a much more powerful ampli-

fier than that which is built into a typical