To reduce the noise reduction measures three commonly used, namely in the sound source noise, noise reduction and noise reduction in the process of communication in the human ear, are passive. In order to take the initiative to eliminate noise, people invented the "active control" of this technology. Its principle is: all the voices are composed of a the spectrum, if you can find a voice, the noise spectrum and to eliminate completely the same, just the opposite phase (180 degrees), can be fully offset the noise. The key is how to get the offset noise. The practical approach is: starting from the noise source itself, try to through the electronic circuit to the original phase noise upside down. Thus, the active noise control technology is actually fire with fire.
Sound is produced by the vibration of the form, and spread of vibration in the elastic medium is sound, in a certain frequency range (20 ~ 20000Hz) of the acoustic effect on ear had a sound feeling. The noise (noise) is usually defined as "unwanted sound" (unwanted sound), is a kind of environmental phenomena. People are exposed to the noisy environment, the noise is produced by a variety of human activities in the environmental pollutants. The vibration (vibration), the object (or part of an object) periodic reciprocating motion along a straight line or curve and the equilibrium position made. It exists widely in nature and engineering circles.
Since vibration is the source of noise, vibration and noise reduction now in practice, by solving the vibration can effectively solve the problem of noise. In the noise control of common sheet metal, such as pipe wall vibration air power machinery, machine shell, body and hull often made of thin metal plates, when the machine is running, the thin plate it will produce vibration, noise and radiation, such as caused by structure vibration noise of metal plate is called structural noise. For effective methods to control the radiation noise of this metal plate, one is in the design, reduce the noise radiation area, remove the metal surface is not necessary; the two is coated with a layer of damping coating in the metal structure, the use of damping coating structure vibration suppression, noise reduction, this method is called damping (vibration, damping) is a kind of active noise reduction technology.
with a motorcycle handle Simple and convenient disassembly, a key PTT remote control switch at any time, security, when the police left the motorcycle on duty when it can be removed after the remote PTT is worn on a finger or butt, the police can still use a Bluetooth remote control intercom in motorcycle left within 50 meters.
Through a horn adapter Bluetooth connection, you can shout through a helmet or a hand.
Double PTT Bluetooth handy hand:
Through interphone Bluetooth adapter we can put intercom voice synchronous transmission to the helmet headset and Bluetooth microphone in hand police. The police took the helm in the field of law enforcement when using direct communication with Bluetooth hand (especially in the hot summer of police officers on duty at the scene to remove the helmet) to realize the continuity of communication. Sure. You don't miss any messages in the line of duty.
Through the interphone Bluetooth adapter connection, the information can be transmitted to the helmet headset and the hand.
Helmet Bluetooth HEADPHONE:
At the same time can be connected with the horn loudspeaker, interphone, remote PTT, vehicle or mobile phone four devices, at the same time and there is helmet headset intercom mobile phone communications, and for a particular set of high security, when you press PTT to switch to the helmet headset and mobile phone walkie talkie reply, do speak respectively while listening to the mutual confidentiality.
Receive information and output from the headquarters base station and reply.
Bluetooth version: V3.0 Class1
Bluetooth protocol: HSP HFP SPP
Waterproof level: IP66
Charging time: 3 hours
Working hours: about 12 hours
Communication distance: 30 meters
Microphone type: DSP de-noising single point microphone
Battery type: rechargeable lithium battery 600mA/3.7v