Yamaha RX-V730 owner manual Elements of a sound field, Early reflections, Reverberations

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.

•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:

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 for any

particular environment, and provide vital information to

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

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 digital sound field processor

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 digital sound field processor.

DSP programs consist of some parameters to determine

the apparent room size, reverberation time, distance from

you to the performer, etc. In each program, these

parameters are set with values precisely calculated by

YAMAHA to create a sound field unique to the program.

It is recommended to use DSP programs without

changing the values of parameters. However, this unit also allows you to create your own sound field by starting

with one of the built-in program and adjusting its parameters.

Each DSP program has a set of parameters that allow you

to change the characteristics of the acoustic environment to create the precise effect you want. These parameters

correspond to the many natural acoustic factors that create

the sound field you experience in an actual concert hall or

other listening environment. The size of the room, for example, affects the length of time between the early

reflections. The "ROOM SIZE" parameter provided in many of the DSP programs alters the timing between

these reflections, thus changing the shape of the "room"

you are listening. In addition to room size, the shape of

the room and the characteristics of its surfaces have a

significant effect on the final sound. Surfaces that absorb

sound, for example, cause the reflections and

reverberations to die out more quickly, while highly

reflective surfaces allow the reflections to carry on for a longer period of time. The digital sound field parameters allow you to control these and many other factors that

contribute to your personal sound field, allowing you to

essentially "redesign" the concert halls, theaters, etc.

provided to create custom-tailored listening environments that ideally match your mood and music.

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