Sensitivity
Speaker sensitivity.
This characteristic is indicated on the basis of how loud the acoustics are capable of producing when a signal of a certain standard power is applied to it. Simply put, the higher the sensitivity of the speaker, the louder it will sound at the same output power of the amplifier. Thus, sensitive acoustics can be effectively used even in combination with relatively low-power "amplifiers". On the other hand, low sensitivity also has its advantages: it allows you to achieve a more uniform frequency response and reduces the likelihood of overloading the amplifier. In the least sensitive modern speakers, this indicator
does not exceed 84 dB, in the most sensitive it is
95 – 96 dB or
more.
Note that in fact, you have to pay attention to this parameter when acoustics are planned to be used with a separately selected power amplifier. Therefore, for active systems (see "Type"), sensitivity is purely a reference value, and, usually, it can be ignored when choosing.
Overall frequency range
The total frequency range that the speaker is capable of reproducing. Specified from the bottom of the range in the lowest frequency component to the top of the range in the highest frequency: for example, in a 2.1 system with main speakers at 100 – 22000 Hz and a subwoofer at 20 – 150 Hz, the total value will be 20 – 22000 Hz.
The wider the frequency range — the fuller the reproduced sound, the lower the likelihood that some part of the low or high frequencies will be "cut off". It is worth noting here that the human ear perceives frequencies on average from 16 Hz to 22 kHz, and from a practical point of view, it makes no sense to provide a wider frequency range in speakers. However, quite a few models go beyond this range, sometimes quite significantly (for example, there are speakers with a range of about 10 – 50,000 Hz). Such characteristics are a kind of "side effect" of high-end acoustics, and they are usually given for advertising purposes.
Thus, the lower limit of the range in modern speakers can be within frequencies
up to 20 Hz, however, higher values \u200b\u200bare more common —
30 – 40 Hz,
40 – 50 Hz, or even
more than 70 Hz. In turn, the upper limit in most modern speakers lies in the range
19 – 22 kHz, although there are deviations both upwards (see above) and
downwards.
Bluetooth
The presence or specific version of the
Bluetooth module installed in the speaker system.
The most common way to use such a module is to broadcast sound from smartphones, tablets, laptops and other Bluetooth devices to acoustics. The main convenience of such a connection is obvious — it is the absence of wires and the corresponding freedom of movement, especially since the Bluetooth range is usually at least 10 m (within line of sight). However, note that without special technologies, the audio signal during such a transmission is highly compressed, which affects the final sound quality; so aptX support is required to achieve good quality (see below).
In addition, Bluetooth can be used for other purposes; the most popular option for such an application in the AU is remote control from an external device. However, such features are much rarer.
As for different versions of Bluetooth, they differ both in terms of bandwidth and accessibility. Here is a description of the different options used in the AU.
- Bluetooth v2.0. The oldest of the versions found nowadays. Provides only basic capabilities and up to 2.1 Mbps communication speed, and is also much more prone to compatibility issues than newer standards. Therefore, this version can be found mainly among frankly outdated acoustics.
- Bluetooth v2.1. An updated version of the 2.0 standard, which received a number of improvements regarding the compatibility of...different types of devices and connection security. It is a kind of "classic of the genre", all newer generations of Bluetooth are basically v2.1 plus various additions and improvements.
- Bluetooth v3.0. A version in which a high-speed channel of 24 Mbps was added to the basic capabilities of Bluetooth 2.1 — for exchanging large amounts of data. At the same time, the Bluetooth module automatically determines the amount of transmitted information and selects which connection to use — regular or high-speed.
- Bluetooth v4.0. A fundamental update (after version 3.0), which introduced another data transfer format — Bluetooth Low Energy (LE). This protocol is designed mainly for miniature devices that transmit small amounts of information. Nevertheless, it allows you to significantly save energy when working with larger equipment, such as speakers — in particular, the energy costs for transmitting small service data packets are reduced.
- Bluetooth v 4.1. Development and improvement of Bluetooth 4.0. One of the key improvements was the optimization of collaboration with 4G LTE communication modules — so that Bluetooth and LTE do not interfere with each other. So if a 4G smartphone is often in close proximity to Bluetooth speakers, it is desirable that these speakers have a module with a version of at least 4.1. Another interesting innovation is the ability to simultaneously use a Bluetooth device in several roles (for example, to remotely control an external device while simultaneously streaming music to headphones). However, this point is more relevant for signal sources than for speakers.
- Bluetooth v4.2. Further, after 4.1, the development of the Bluetooth standard. It did not introduce fundamental updates, but received a number of improvements regarding reliability and noise immunity, as well as improved compatibility with the Internet of Things.
- Bluetooth v5.0. Version introduced in 2016. One of the key innovations was two special modes of operation of Bluetooth low energy: speed up mode (by reducing the range) and long range mode (by reducing the speed). In addition, a number of improvements have been introduced regarding the simultaneous operation with numerous connected devices.
Woofer size (LF/MF)
The diameter of the woofer or combined woofer/midrange speaker(s). The larger the speaker, the lower its operating frequencies and the more sound power it can provide. Therefore, you should pay special attention to this parameter if you want to get high-quality rich bass - especially if we are talking about an audio system without a subwoofer. More detailed information about speaker sizes can be found in special sources.
Weight
The total weight of all components of the speaker system.