The front surface of a YSP unit features a number of compact beam speakers* installed in orderly rows. Control of each of these speakers on a time axis by individual amps creates five sound beams. Bouncing these sound beams off walls creates a surround environment.

* YSP-3300: 16; YSP-4300: 22

1. Sound produced from the speakers is transmitted radially from the sound source, like an expanding ripple (Fig. 1).
2. The sound waves from two speakers are superimposed, creating interference (Fig. 2).
3. If the number of speakers in adjoining locations is increased, the sound waves are superimposed even more, so the sound is transmitted as a single strong wave. This is a sound beam (Fig. 3).
4. By using a processor (dedicated Yamaha LSI) to control the times when each speaker produces sound, the direction of the sound beams can be controlled (Fig. 4).
5. Controlling the directions of the beams to bounce them off the walls enables the sound to come from five directions: front left and right, rear left and right, and centre. Models from the YSP-4300/3300 create two phantom sound sources in addition to the five beams, to provide 7.1-channel surround sound.

When the microphone is placed at the listening position, it searches for the places suitable for reflecting the beams while it checks the size and shape of the room and the quality of the wall material, in order to automatically adjust the beam angle, the volume and the sound quality. This makes it easy to achieve the best surround sound environment.