Yamaha Technology



Yamaha Technology -1

Adaptive echo canceller

Eliminates audio cut-out and echo for smooth full-duplex performance.
Echo occurring due to sound from the speakers feeding back into the microphones is eliminated by the echo canceller.

Features of the adaptive echo canceller
What is echo?
Echo prevention methods compared

Features of the adaptive echo canceller

Smooth two-way talks

Echo is a phenomenon that often occurs when the microphones pick up the audio reproduced from the speakers in an audio conference system. To counter this, the Projectphone incorporates a high-performance adaptive echo canceller that eliminates any of its own sounds that it may pick up. Combining this with a design that minimizes feedback of reproduced sound, it offers smooth full-duplex performance that is easy on both the talkers and listeners. In addition, the PJP-100H incorporates a 3-channel adaptive echo canceller that enables you to remotely specify audio output from each speaker position (Divide mode).

Designed for use in any kind of room

Removes echo even in a room with high reverberation The Projectphone's adaptive echo canceller automatically adjusts the echo-filter factor to the optimum setting for a given environment. With the Projectphone, you can hold a meeting in any type of room or space.


What is echo?

Echo is a phenomenon that occurs when microphones pick up the audio reproduced from the speakers. Echo tends to occur more often with an audio conference system than with a telephone set on which the microphone and speaker are isolated from each other. The Projectphone incorporates a high-performance adaptive echo canceller that reproduces voices with higher clarity by eliminating echoes.

Echo prevention methods compared

TYPE-1 Echo suppression

By lowering the microphone gain when playing back sound from the unit's own speakers, echo is prevented by physically ensuring that sound is not picked up by the microphones in the first place. Because the microphones are turned OFF while sound is output from the speakers, audio occurs in a one-way "transceiver" format. However, this increases the likelihood of audio cut-out.


This technique suppress echoes by prioritizing the microphones nearest the loudest voices and switching off the ones nearest the softest voices.

Audio is one-way only. Sound cuts out easily.



TYPE-2 Adaptive echo cancelling

Any voices picked up from the speakers by the microphones are cancelled with filters (signal processing).

Two-way talks are possible without audio cut-out.






Yamaha Technology - 2

Arrayed microphones

High performance audio pickup for conferences with clear audio.
The Projectphone picks up the typical exchanges that occur during meetings so accurately and smoothly that conference participants hardly notice its presence.

Features of the arrayed microphones
Arrayed microphone pickup control
Variety of pickup modes

Features of the arrayed microphones

Arrayed microphones deliver clear pickup

Microphones arranged in an array combine their sounds for clearer pickup than with a single microphone. The PJP achieves clear, easily audible pickup by adding together the sounds from the individual microphones and controlling delay with a DSP.

Directional pickup performance strengthened with microphone beamforming

Beamforming microphone pickups can enhance their directional performance. The Projectphone forms a pickup beam horizontally from the microphones in the direction of the talker to raise pickup performance and simultaneously reject ambient noise. It is also designed to resist echo-causing feedback (sound from the speakers returning after reflecting off walls or ceilings).


Arrayed microphone pickup control

  • PJP-100H
  • PJP-100UH
  • PJP-50R


The narrow-directivity arrayed microphones sense the delay in received sound to automatically detect the location of its source, and pick up voices clearly. You can specify audio pickup areas from which ambient noises are eliminated (such as ventilation systems and projectors), providing a noise-free meeting environment that lets attendees concentrate.


Variety of pickup modes

  • PJP-100H
  • PJP-100UH
  • PJP-50R



The sound source detection technology of the arrayed microphones provides the Projectphone with various audio pickup modes. It enables not only pickup of a sound source in a large area, but also specification of a particular audio pickup area if needed. In addition, it automatically tracks sound coming from the direction of the talker, and clearly picks up only the talker's voice. With a combination of sound source detection and high-performance adaptive echo cancelling, you can hold a meeting in any environment.

MODE-1 Zone mode
Zone mode ideal for quiet rooms
Zone mode is recommended for quiet rooms because of its wide audio pickup range. Thanks to the high audio pickup performance of the arrayed microphones, voices are picked up accurately even when distant from the microphones. Because the pickup range can be adjusted, you can ensure that even noises such as from air conditioners and projectors are not picked up.


MODE-2 Spot mode
Spot mode ideal for noisy environments

In this mode, the narrow directivity of the arrayed microphones allows you to pick up sound only from a specific direction. It is the optimal mode for conferences limited to one or two participants, or in noisy environments. Even in open spaces or when surrounded by noise, only the unadulterated voices of the talkers are heard by the other party.


MODE-3 MODE-3 Track mode
Tracking mode automatically detects the talker

A microphone beam position detection function automatically tracks in the direction of the talker. Only the unadulterated voice of the talker is picked up. Also, by setting the PJP to pick up in a certain direction, you can ensure that it will not track noise sources such as projectors. Because pickup is directed toward the talker, this mode is useful for multiperson conferences where noise sources are present.





Yamaha Technology -3

Acoustic design

Acoustically engineered structural design
The arrayed microphones and speakers are arranged optimally to be easy on the listeners and easy on the talkers.

Sound design features
Divide mode
Talker position reproduction

Sound design features

Structural design based on acoustic engineering
The Projectphone was designed with acoustic engineering principles in mind to achieve clear, easily audible voice pickup and reproduction specialized for conferences. The arrayed microphones are arranged based on hole mountin according to the frequency characteristics of the human voice. The design also reconciles outer appearance with sound, such as by orienting the speakers to direct the best part of the sound toward the human ear.

 

HiFi speakers
Using carefully selected high performance speakers for HiFi audio, the Projectphone offers clearly audible sound along with superb audio quality for non-conferencing uses.

 

Speaker arrangement

The PJP-100H, PJP-100UH, and PJP-50R control small-diameter HiFi speakers to produce a point audio source, and adopt an acoustic design that accounts for the conference table and locations of participants. It produces clearly-audible output using a horn loading effect created by the speakers' synthesized acoustic wavefront. The PJP-25UR is also packed with ingenious solutions that target the best sound towards people's ears, such as with the closely-placed small-diameter speakers that project sound outward horizontally.


Divide mode

  • PJP-100H
  • PJP-50R


Clearly audible multilocationconferences without crossing
During multilocation conferences, voices can be reproduced from different speakers according to the locations of the talkers. Outputs without crossing not only make voices easily audible, but also enable easy identification of the location of the current talker.
  • ・World's first 3-channel echo canceller
  • ・Voices are positioned and reproduced according to the locations of the talkers to ensure clear audio output without crossing, even during multipoint conferences.
  • * Only available when connecting a PJP-100H/PJP-50R with a mesh connection.


Talker position reproduction

  • PJP-50R


The microphone array's talker detection function and the speaker array's virtual sound source generation function combine to facilitate the "talker position reproduction mode" that modifies audio output according to the seating arrangement of the callers. Sound is output at different positions making it easy to distinguish between multiple voices (up to three talkers per location over a two-location IP conference).



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