Apogee APL-10 Spécifications télécharger pdf (Page 20)

Using the

APL-10/12

(1) Overview

The APL-10/12 can be used in many ways and for many applications. In its

simplest form, one APL-10/12 placed at each side of the stage will add dra-

matic low frequency impact to a typical full-range system in a club, church, or

theatre.

A full-blown array of fifty or sixty APL-10/12 speakers, properly positioned,

can provide intense low-frequency power for large-scale concerts, both

indoors and out.

The nature of low-frequency sound waves and how they behave in space

should be understood, at least in rudimentary form, to operate an APL-10/12

system to your best advantage. Low frequency waves are very long. A 30 Hz

wavelength is approximately 35 feet in length and a 100 Hz wavelength is

approximately 11.3 feet in length (varying a bit with temperature).

Because low-frequency waves are significantly greater in length than higher

frequency waves, they behave quite differently than other wavelengths.

First, a long waveform does not ‘see’ a small or moderate-sized obstruction

as an obstacle; it simply diffracts around the barrier as if it’s not there.

Second, the substantial length of low frequency waves makes it difficult to dis-

tinguish their source direction. (This is why a single subwoofer can often be

used to augment a stereo pair of full-range speakers, without sacrificing

stereo separation and image.)

Third, low frequency waves tend to join together very graciously (if they are

in phase and in time with one another), even if their sources are separated

by a considerable distance. Most professional sound engineers have experi-

enced an intense bass elevation in the middle of certain rooms, generated by

a stack of speakers placed at either side of the stage.

Understanding how low-frequency waves transmit can be very helpful in

planning and designing optimum sound systems. There are many useful texts

available on this subject. Recommended reading: "Fundamentals of Sound"

and "Psychoacoustics" by F. Alton Everest in the "Handbook for Sound

Engineers" published by Howard Sams & Co.

To help you get the most from your APL-10/12 powered loudspeakers, here

are some basic guidelines.

(2) Placement

The APL-10/12 will benefit greatly in terms of power output by being placed

adjacent to a boundary surface (or surfaces). In practical terms, this means

putting the APL-10/12 on the floor, on the ground, by a rear wall or ceiling

(being careful not to restrict air flow to the heat exchanger), or in a corner.

1 2 ... 15 16 17 18 19 20 21 22 23 24 25 ... 35 36

Pas de commentaire

Apogee APL-10 Spécifications Page 20