Sources and media
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Bluetooth. Wireless technology for transmitting sound from mobile phones, tablets, etc. Allows you to connect a device wirelessly at a short distance from the signal source. The quality and overall capabilities of Bluetooth vary depending on the version:
Bluetooth 4. Each version brings improvements relative to the previous one. So in version 4.0, three standards were actually combined: traditional Bluetooth, a high-speed channel and an energy-saving mode for small amounts of data. This allowed us to optimize channel usage and battery consumption. In version 4.1. Noise immunity has been enhanced when working next to 4G LTE modules. And version 4.2 introduced mainly general improvements in speed and security.
Bluetooth 5.0. One of the most important innovations of the Bluetooth 5.0 standard is the expansion of the capabilities of the BLE (Bluetooth Low Energy) mode: if necessary, the device can increase the range by reducing the speed, or speed up transmission by reducing the range. In addition, a number of improvements have been introduced regarding simultaneous work with multiple connected devices.
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Bluetooth 5.1. A significant upgrade in version 5.1 was the ability to accurately position the signal transmitter (receiver). If previous versions could only determine distance, then version 5.1 can a
...lso determine direction. Thus, navigation began to function better and more accurately, which improved work with the smart home system, searching for connected devices, etc. In addition to this, the improvements again concerned saving energy consumption and simultaneous work with several connected devices.
- Bluetooth 5.2. The next update, after 5.1, is Bluetooth 5th generation. The main innovations in this version are a number of security improvements, additional optimization of power consumption in LE mode and a new audio signal format for synchronizing parallel playback on multiple devices.
— Bluetooth 5.3 The Bluetooth v 5.3 wireless communication protocol was introduced at the dawn of 2022. Among the innovations in it, they accelerated the process of negotiating a communication channel between the controller and the device, implemented the function of quickly switching between the operating state in a low duty cycle and a high-speed mode, and improved the throughput and stability of the connection by reducing susceptibility to interference. When unexpected interference occurs in Low Energy mode, the procedure for selecting a communication channel to switch from now on has been accelerated. There are no fundamental innovations in protocol 5.3, but a number of qualitative improvements are evident in it.
- Bluetooth 5.4. The version was presented at the beginning of 2023, the range and data exchange speed were increased. Also in Bluetooth v 5.4, the energy-saving BLE mode has been improved. This protocol uses new security features to protect data from unauthorized access, has increased connection reliability by selecting the best channel for communication, and prevents connection losses due to interference.
—Mini-Jack (3.5 mm). Standard Aux audio input for connecting speakers to an audio source, such as a laptop or smartphone.
- USB. The presence of a USB connector allows you to connect a flash drive, mobile phones, MP3 players and other similar peripherals to the portable speakers. Accordingly, such models have a built-in player and allow you to use connected gadgets exclusively as a drive.
- Card reader. Like the USB described above, this item implies the presence of a built-in player in the acoustics. And the card reader allows you to use memory cards as a drive on which songs will be recorded.
— FM receiver. A built-in tuner allows the speaker system to work as a full-fledged FM radio receiver - this is the range that is popular among music radio stations (in particular, due to the ability to broadcast sound in stereo format).Number of channels
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Mono. The simplest type of acoustics is a single-channel audio system equipped with one speaker. Of course, there is no question of any volume of sound.
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Stereo. Acoustic system equipped with two speakers responsible for the left and right channels. Allows you to create a minimal illusion of "surround" sound by simulating the displacement of the sound source in the space in front of the listener.
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2.1. A system of two stereo speakers that create a minimal illusion of "surround" sound, and a subwoofer that provides powerful and rich sound at low and ultra-low frequencies.
Lines
A band is a specific part of the frequency range reproduced by an acoustic system. In single-way acoustics, only universal speakers are used that are responsible for the entire operating range. The presence of several bands means the use of specialized speakers, “tailored” to certain frequencies: for example, in two-way speakers, separate high-frequency “tweeters” are most often provided, and in three-way speakers the frequencies are divided into low, medium and high.
For different frequencies, the optimal speaker design will also be different; thus, the multi-band design allows for better sound quality. On the other hand, single-way speakers are lighter, more compact and less expensive. This is exactly what most portable speakers are, since Hi-Fi sound is not alien to them.
Signal-to-noise ratio
The ratio of the level of the useful signal (the actual sound being reproduced) to the level of extraneous noise provided by the speaker amplifier in normal mode.
Any amplifier inevitably creates its own noise; You cannot get rid of them, but you can reduce their level. The higher the signal-to-noise ratio, the cleaner the sound will be, the less noticeable extraneous interference will be. However, it is worth keeping in mind that the signal-to-noise ratio is far from the only parameter that affects sound quality, and its high value does not guarantee pleasant sound from the speakers.
Sound pressure level SPL
The SPL (Sound Pressure Level) parameter determines the sound volume of portable acoustics. This indicator is expressed in decibels (dB). The higher the SPL, the louder and farther the sound produced by the speaker travels. It is important to consider that decibel is a non-linear quantity. In other words, increasing the volume from 20 dB to 40 dB or from 40 to 80 dB does not mean increasing it by 2 times. Therefore, when making an assessment, it is most convenient to refer to comparative tables of noise levels in special sources.
Passive emitter
The presence of a
passive radiator in the design of the speaker system.
Such an emitter is a speaker cone that does not have its own coil and magnet — in other words, it does not produce sound itself, but only vibrates from the sound of other speakers. Like the phase inverter (see above), this part is intended to improve sound pressure and sound depth, especially at low frequencies; at the same time, the advantage of a passive radiator is the absence of a tube, due to which the design is simpler and more compact than with a phase inverter.
Output power
The total power of all channels of the speaker system. The higher the power, the larger the size of the room in which the audio system can be used, however, more
powerful portable speakers usually have larger dimensions and weight.
Frequency range
The range of audio frequencies reproduced by the audio system. The wider the range, the richer the sound, the more details the speakers can convey, especially in the low and high frequencies. At the same time, we note that the average human ear is able to hear sounds in the range of about 16 – 20,000 Hz, and it makes no sense to provide a wider range in speakers — a person simply will not hear it. Also note that a wide frequency range alone does not guarantee good sound quality.
Speaker synchronization
The model supports the ability
to synchronize the operation of several speakers connected to one signal source. This solution allows you to realize truly stereo sound, improve the quality and power of sound reproduction, and also expand the stereo panorama. The only thing is that both speakers must support the appropriate connection type. Different brands may have their own technologies for combining speakers (JBL Connect, JBL PartyBoost, Sony Party Chain), or maybe a universal TWS.