Bluetooth home theater: device, features of work

Bluetooth is a type of wireless communication that allows different devices to communicate at a particular radio frequency. This technology has been effectively applied in modern home cinema, thus opening the "era of wireless cinema." Home theater equipped with bluetooth function has its advantages and disadvantages.

Home theater without wires

Wireless signal transmission methods are far from new: they existed 15-20 years ago. Such technology was used in professional concert equipment, for example, in radio microphones and electric guitars. Then wireless technologies have stepped into the world of amateur audio systems. Acoustic signal in modern home theaters wirelessly transmitted:

• using bluetooth;
• using the transmitter via Wi-Fi;
• radio waves.

Bluetooth Home Cinema

Bluetooth technology allows digital devices to exchange information at a certain distance (usually no more than 10 meters) over a wireless connection. The Bluetooth function in a home theater can be implemented in two ways:

1. Wireless audio reception from a smartphone, laptop, tablet to a home cinema signal source (receiver, media player, etc.) with its further transmission to wired speakers.
2. Beep transmission to acoustics wirelessly within the system.

Different cinemas can combine these functions, that is, they can receive and transmit wirelessly. But at the same time, there are home systems that can receive data from an external bluetooth source, and transmit it to the acoustics in a wired way. And they are also called wireless home theaters.

Disadvantages of a wireless system

The emergence of Bluetooth-cinema was the producers' response to the discontent and discomfort of the owners from the wires and cables stretching across the room to the speakers.But the task of freeing the speakers from wires, as it turned out, is not so easily solved. Difficulties associated with the following points:

1. Acoustic system of modern home theater consists of 6 or more channels. In case of failure of the wires, you must install a receiver, a DAC converter, a good quality analog amplifier in each wireless speaker. Such a bunch of electronics will cost, according to manufacturers, not just expensive, but unjustifiably expensive. But, on the other hand, laying a cable, repairing the floor, walls and ceiling is also not the cheapest pleasure.
2. A column with such a serious filling becomes active and introduces its share of distortion into the signal.

In many modern home theaters with Bluetooth function, only rear speakers are wireless, and they still have wires.

With their help, they are connected to the power supply. But sockets for powering such speakers look more inconspicuous and aesthetically pleasing than wires throughout the room. However completely wireless acoustics also exists. For example, in the Philips CSS5235Y home theater audio system, the acoustic signal is transmitted to the acoustics via Bluetooth.The rear speakers, in fact, are the terminations of the front speakers, turning the 2.1 stereo system after removing into 4.1-channel surround sound with Surround Demand. So, these rear speakers fully wireless. After 5 hours of work, they need to be returned for charging to the front speakers.

Receive audio files via Bluetooth

Output sound files from a smartphone, laptop or tablet is carried out on one principle:

1. Audio files from a mobile device, which also has a Bluetooth chip, are transmitted to the receiver.
2. The signal is decoded, divided into channels, then branched.
3. Some channels are transmitted to the amplifier and then to the front and center speakers using wire technology.
4. Another part of the channels is recoded and distributed to the rear active speakers, where they are received, re-decoded, amplified and released on the air. In the same speakers are transmitted and commands the volume of the sound, the delay time for the realization of spatial sound.

Home theater model Sony BDV-N9100W with Blu-Ray and 5.1 system. distinguishes beautiful sound. The total acoustics power is 1000 watts. Sound to the speakers can be output from any mobile device using the Bluetooth module.Wireless rear speakers connect to a separate amplifier, they do not need to pull the wires throughout the room.

The sound quality of bluetooth cinemas

The sound quality in such speakers still plays the sound that is reproduced wired. In the latter, the signal arrives in analog form, and is also fed into the air without changes and transformations. A digital signal, before it is reproduced in the active (rear speakers), goes through the stages of additional encoding and decoding, which can not but affect its quality. Although today on the market you can find models with sound recovery system.

Bluetooth interference

Home theater with a Bluetooth device may not work correctly:

1. If the user accidentally touches the receiving or transmitting part of a mobile device or movie theater.
2. If the phone or tablet is at a great distance from the home theater reception system. If you increase the distance by more than 10 m, the connection may be interrupted.
3. Even within the specified range, communication may be interrupted if obstacles in the form of doors or walls arise.
4. In the presence of a nearby large electric field.
5. With simultaneous pairing of multiple gadgets with Bluetooth.
6. Interference can create microwave ovens, a wireless internet adapter, fluorescent lights, and even gas stoves. These devices work on the same frequency as Bluetooth.

The wireless device itself may also interfere.

Important nuances

When pairing a mobile device and a home theater system, it is important to consider a few points. To preserve audio quality, the SBC audio codec must be installed on the receiver or source. Different home theaters support different quality SBC data:

• midrange up to 237 kbps at 48 kHz;
• high level 328 kbps at 44.1 kHz.

You also need to pay attention to the supported profile. Modern home theaters with Bluetooth function use A2DP profile.

Auxiliary technology for transferring data from a mobile device is NFS, which facilitates a Bluetooth connection. The user does not need to dig in the settings, it is enough to bring, for example, a smartphone to a home theater device, touch it and confirm the connection. By the way, using wireless technology can be done home theater control from a smartphone, tablet or computer.