Comparison Marshall Stockwell II vs Marshall Kilburn II

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.

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.

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.

Initially, sound transmission via Bluetooth involves quite strong signal compression, which can greatly spoil the experience when listening to music. To eliminate this drawback, various technologies are used (the most popular of which is the aptX codec). Of course, to use any of the technologies, it must be supported not only by the sound system, but also by the Bluetooth device with which it is used.

- aptX. A Bluetooth codec designed to significantly improve the quality of audio transmitted over Bluetooth. According to the creators, it allows you to achieve quality comparable to Audio CD (16-bit/44.1kHz). The benefits of aptX are most noticeable when listening to high-quality content, but even on regular MP3 it can provide a noticeable sound improvement.

- aptX HD. This codec is a further development and improvement of the original aptX technology, allowing you to transmit sound in even higher quality - Hi-Res (24-bit/48kHz). According to the creators, this standard allows you to achieve signal quality superior to AudioCD and sound purity comparable to wired communication. The latter is often questionable, but it can be argued that overall aptX HD provides very high sound quality. On the other hand, all the advantages of this technology become noticeable only on Hi-Res audio - with quality 24-bit/48kHz or higher; otherwise, the quality is limited not so much by the characteristics of the connection as by the propertie...s of the source files.

- aptX Low Latency. A specific version of aptX described above, designed not so much to improve sound quality, but to reduce delays in signal transmission. Such delays inevitably occur when working via Bluetooth; They are not critical for listening to music, but when watching videos or playing games, there may be a noticeable desynchronization between the image and sound. The aptX LL codec eliminates this phenomenon, reducing latency to 32 ms - such a difference is imperceptible to human perception (although for serious tasks like studio audio work it is still too high).

- A.A.C. A codec used primarily in Apple portable devices to improve sound transmitted via Bluetooth. In this sense, it is similar to aptX (see the corresponding paragraphs), but is noticeably inferior to it in terms of capabilities: if the sound of aptX is compared with Audio CD, then AAC is at the level of an average quality MP3 file. However, for listening to the same MP3s, this is quite enough; the difference becomes noticeable only on more advanced formats.

-LDAC. Sony's proprietary Bluetooth codec. It surpasses even aptX HD in terms of bandwidth and potential sound quality, providing performance at the Hi-Res level of 24-bit/96kHz audio; there is even an opinion that this is the maximum quality that it makes sense to provide in wireless headphones - further improvement will be simply imperceptible to the human ear.

— Microphone for speakerphone. The ability to use portable speakers as a speakerphone system for conversations on a paired mobile phone. In this mode, the speakers connect to the device via Bluetooth, and the speech is transmitted to the interlocutor using the built-in microphone. The voice of the subscriber on the other end of the line is output not to the speaker of the phone, but directly through the speakers of the speaker system. This is often much more convenient than holding the phone close to the ear, or in situations when your hands are busy. In addition, speakerphone can be very useful if several people need to participate in the conversation.

— NFC chip. NFC is a short-range wireless communication technology (about 10 cm). It allows for many different uses, but in portable speakers it is usually used as an addition to Bluetooth, making it easier to set up a communication. For example, a smartphone with an NFC module can simply be brought to a speaker with the same function — and both devices will automatically recognize each other, and the user will only need to confirm the communication.

— Multipoint. The technology used in Bluetooth models allows the speaker to connect to several devices simultaneously. Thanks to this, you can, for example, listen to music from a laptop, and when a call comes in on your mobile phone, switch the speakers to a c...onversation. Different manufacturers have their own features of this technology, and therefore, if the multipoint function is critical for you, you should separately clarify the details of its operation in the selected model.

— Bass Boost. A function that provides amplification of low frequencies — for powerful and rich bass. Often implemented as a single button, with which you can actually "turn the bass on and off." Bass Boost is more convenient than adjusting low frequencies using an equalizer; in addition, various special technologies can be used to enhance bass.

— Mobile application. The ability to operate the functions and settings of portable sound system through a mobile application for a smartphone or tablet. The device usually communicates with gadgets via the Bluetooth wireless protocol. The proprietary software may include tools for flexible sound adjustment (equalizer, bass boost, etc.), wireless communication management, sound source selection, etc. Also, the ability to update the firmware of portable sound system is often implemented through a mobile application.

— Light effects. Such effects can be different — from the simplest set of lights flashing at a constant frequency to advanced color music systems that produce multi-colored patterns in time with the music being played. In any case, this function has more of an entertaining meaning and does not affect the sound of the device in any way.

The time it takes to charge a fully discharged device to 100% charge.

- microUSB. One of the miniature versions of the USB connector, still popular in portable gadgets, despite the emergence of the more advanced USB C. It has relatively limited capabilities (in particular, it is inferior to USB C in terms of the maximum possible charging power), but this point is rarely critical. At the same time, there are a great variety of cables and chargers for microUSB.

- USB C. A relatively new type of USB connector that is actively gaining momentum. Like microUSB, it has miniature dimensions, but has a more convenient double-sided design and advanced capabilities, in particular the ability to transmit higher power, which has a beneficial effect on charging time.

The presence in the design of the acoustics of a protected housing that prevents dust and moisture from entering the sensitive electronic filling. The specific degree of such protection in different models may be different — some speakers are able to endure even complete immersion under water ( waterproof), others are designed only for exposure to moderate rain. Therefore, the specifics of the protected case should be clarified separately according to the manufacturer's official data. However, anyway, such speakers will be more resistant to bad weather and better suited for outdoor use than those that do not have dust and water protection; therefore, if you are choosing acoustics for outdoor trips, it makes sense to pay attention to models with this function.

Some models with this feature are officially IP certified. The IP index includes two digits — for example, IP54. The first digit indicates the degree of protection against dust, the second — from moisture; the higher the number, the higher the corresponding degree of protection, detailed data can be found in special sources.