Yamaha DSP -A780 Kullanım Kılavuzu - Sayfa 35

Amplifikatör Yamaha DSP -A780 için çevrimiçi göz atın veya pdf Kullanım Kılavuzu indirin. Yamaha DSP -A780 42 sayfaları. Digital sound field processing amplifier

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CREATING YOUR OWN SOUND FIELDS

3-1. SELECTING AND EDITING PROGRAM PARAMETERS

WHAT IS A SOUND FIELD?

In order to explain the impressive functions of the DSP system,

we need to first understand what a sound field really is.

What really creates the rich, full tones of a live instrument are the

multiple reflections from the walls of the room. In addition to making

the sound "live", these reflections enable us to tell where the player is

situated, and the size and shape of the room in which we are sitting.

We can even tell whether it is highly reflective, with steel and glass

surfaces, or more absorbent—wood panels, carpeting and curtains.

THE ELEMENTS OF A SOUND FIELD

In any environment, in addition to the direct sound coming

straight to our ears from the player's instrument, there are two distinct

types of sound reflections that combine to make up the sound field:

(1) Early Reflections. Reflected sounds reach our ears extremely

rapidly (50 ms — 100 ms after the direct sound), after reflecting from

one surface only—for example, from the ceiling or a wall. These

reflections fall into specific patterns as shown in the diagram on page

35 for any particular environment, and provide vital information to our

ears. Early reflections actually add clarity to the direct sound.

(2) Reverberations. These are caused by reflections from more than

one surface—walls, ceiling, the back of the room—so numerous that

they merge together to form a continuous sonic "afterglow". They are

non-directional, and lessen the clarity of the direct sound.

Direct sound, early reflections and subsequent reverberation

taken together help us to determine the subjective size and shape of

the room, and it is this information that the DSP system reproduces

in order to create sound fields.

If you could create the appropriate early reflections and

subsequent reverberations in your listening room, you would be able

to create your own listening environment. The acoustics in your room

could be changed to those of a concert hall, a dance floor, or virtually

any size room at all. This ability to create sound fields at will is

exactly what Yamaha has done with the DSP system.

DSP programs consist of some parameters to determine

apparent room size, reverberation time, distance from you to the

performer, etc. In each program, those parameters are preset with

values precisely calculated by Yamaha to create the sound field

unique for the program. It is recommended to use DSP programs

without changing values of parameters, however, this unit also allows

you to create your own sound fields. Starting with one of the built-in

programs, you can adjust those parameters. Even if power is turned

off, your custom sound fields will remain in the DSP system's

memory for about two weeks. The following pages detail how to

make your own sound fields.