CHAPTER 5

Sonic Holography

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 ne, 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.

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.

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.

stage

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 con nes of the at 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.

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User's Manual

Page 45
Image 45
Sunfire TGR-401-230, TGR401 manual Sonic Holography, To summarize