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Sonic holography, Chapter 5 – Sunfire Theater Grand Receiver TGR-401-230 User Manual

Page 45

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User's Manual

45

CHAPTER 5

Sonic Holography is a unique

process which enhances the three-

dimensional effects and realism of

stereo sound. This is from a design

based on Bob Carver's legendary

(and much sought after) Carver C-9

Sonic Holography Generator.

This circuit was designed to over-

come a problem in obtaining accurate

sound reproduction:

In a stereo system, both ears will

hear the output from both speakers.

The left ear hears sound from the left

speaker and from the right speaker.

To see a problem with this, compare

what happens when listening to a live

musical performance:

During a concert, each ear will

receive one direct sound arrival. For

example, both ears will hear the piano

playing, and your brain tells you ac-

curately the position of the musician. In

a stereo recording of the concert, this

piano will be heard from both speakers.

The left ear will hear the left speaker,

which is fine, but the left ear will also

hear the crash from the right speaker.

These extra sounds tend to confuse the

sense of sound source location.

The stereo effect in a good pair of

headphones is enhanced because the

left ear only hears the left headphone,

and the right ear hears only the right

headphone. There are no extra sound

arrivals.

Sonic Holography

To summarize :

1. A real musical event will create

only two direct sound arrivals,

one at the left ear and one at

the right. We can accurately

judge the depth and positioning

of the piano on stage.

2. Stereo playback will give four

arrivals, as both speakers

are heard by each ear. These

second sound arrivals reduce

our naturally accurate sense of

positioning.

3. Sonic Holography cancels out

the unwanted second arrivals.

The left ear mainly hears the

left speaker and the right ear

mainly hears the right speaker.

The depth and positioning cues

are restored.

Sonic Holography is accomplished

by sending a complex crosstalk signal

from the left and right speakers in

addition to the normal program. These

extra signals are virtually identical to

the unwanted second sound arrivals

but they are out-of-phase with them

and they cancel each other out.

The result is a more three-dimen-

sional and wider soundstage, where

the positioning clues are restored. In

a way, the musicians have been freed

from the confines of the flat plane be-

tween the speakers. You will perceive

them as playing forward or playing

behind the speakers or to one side

or the other, not just somewhere in

between. We recommend that you ex-

periment with its effect, remember that

you are listening for a more accurate

sense of the location of the different

musicians.

Because Sonic Holography works

by phase cancellation of the unwanted

second sound arrivals, accurate

speaker positioning is required. Make

sure that the left speaker is the same

distance away from you as the right

speaker. Follow the front speaker

placement on page 46 to get the best

results. This is the same as any stan-

dard stereo system, only with more

care taken to position the left and right

speakers accurately.

Sonic Holography is engaged using

the remote control or from the front

panel. There is a short mute period

until the circuit is fully engaged or

disengaged.

1. Press the remote's MAIN button a

few times to reach the main menu.

2. Press TG401 to set the remote to

operate the TGR-401.

3. Press PAGE twice to

reach page 3.

HOL ON and OFF

allow you to turn the

Holography on or off.

stage

stage