Comparison Denon D-T1 vs Pioneer X-HM26

— Built-in memory. Own memory allows you to store and play music and other content directly using the audio system, without the use of external media (which can become damaged or lost). Such memory can be based on hard drives or SSD modules; the first option provides good capacity at a low cost, the second is faster and more reliable.

— USB port. A classic USB port, which in this case is usually used for flash drives, external hard drives or other devices with a storage function - for example, miniature audio players. USB functionality includes, at a minimum, direct playback, but may provide other capabilities, such as file sharing with the built-in memory (see above). In addition, if necessary, a connected device (for example, a pocket player) can be charged through this port.

- Card reader. A device for reading information from memory cards; Such media are very popular in modern electronics. Most often, card readers are designed for various versions of SD or microSD cards, but other options may also occur; This point should be clarified separately in each case. The purpose of this function is much the same as the USB port described above: it is primarily used for direct playback, but other functions may also occur.

- CD. Having a CD drive means at least the ability to work with d...iscs recorded in the CD Audio format (up to 74 minutes of high-quality audio, divided into tracks). In addition, modern audio systems often provide support for discs with MP3 files; In this format, one disc can accommodate an entire collection of albums, but the sound quality is lower. And sometimes it is possible to work with optical discs in DVD format.

- Vinyl records. Built-in player for playing music from vinyl records. Technically, such media are completely obsolete, but they still have many loyal fans. In addition, many audio systems with this function support recording to USB (see “Advanced”); this may be useful for vinyl owners who want to transfer their music libraries to more modern media.

In addition to those described above, modern audio systems may include other types of media. For example, some models are equipped with USB type B inputs, so they can connect to a computer via a USB connector and work as computer speakers with advanced capabilities (such as copying music from a PC to an external drive or vice versa).

The total frequency range reproduced by the acoustics of an audio system. Measured from the lower threshold of the lowest frequency speaker to the upper threshold of 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.

In general, the wider the frequency range, the fuller the reproduced sound will be, the less low and high frequencies will be lost due to insufficient acoustic capabilities. On the other hand, do not forget that the actual sound quality also depends on a number of other parameters — primarily the frequency response. In addition, human audible frequencies range from 16 Hz to 22 kHz; deviations from these values are very small, and the upper limit also decreases with age. Therefore, from a practical point of view, it does not make sense to provide too large a frequency range; and impressive performances like 10 – 50000 Hz, found in top-class models, are usually more of a kind of "side effect" of high-quality speakers (and at the same time — a marketing ploy) than a really significant moment.

— RCA. The RCA interface uses coaxial cables with characteristic tulip plugs and corresponding connectors. It can be used to transmit different types of data, but in this case it is meant to connect an audio signal from a preamplifier in analog format, one audio channel per connector. RCA is widely used in modern audio equipment, but its resistance to interference is very modest.

— Mini-Jack(3.5 mm). Standard connector for most modern portable audio equipment. In audio systems, it is mainly used to connect such equipment — primarily pocket media players. It uses analog signal transmission, but its resistance to interference, like that of RCA, is low, and the quality may be even lower due to the fact that both stereo sound channels are transmitted via one cable.

— Coaxial S/P-DIF. An electrical variation of the S/P-DIF standard that uses a coaxial cable with a tulip connector to transmit the signal. This interface should not be confused with the analog RCA described above — despite the identity of the connectors, these standards are fundamentally different: “coaxial” operates in digital format and allows for the transmission of even multi-channel sound over a single cable. Compared to optical S/P-DIF, this interface is less resistant to interference, but more reliable, since the electrical cables are not as delicate.

— Optical. One of the varie...ties of the S/P-DIF standard — along with the coaxial one described above. In this case, the signal is transmitted via a TOSLINK fiber-optic cable. The main advantage of this interface is its complete insensitivity to electrical interference, while its capabilities are sufficient even for working with multi-channel sound. Among the disadvantages, it is worth noting the high price of connecting cables, as well as the need for careful handling of them.

— For microphone. Input for connecting a microphone to an audio system; can use different types of connectors (3.5 mm mini-Jack, 6.35 mm Jack, etc.). This function is mandatory for models with karaoke (see "Additional"), but can also be used for other purposes.

— Instrumental. Connectors used to connect musical instruments (acoustic or bass guitars, keyboards, etc.). Most often, they are made in the form of 6.35 mm Jack sockets. The audio signal from the pickups has its own specifics, so the instrument input is usually characterized by a higher input signal level and special impedance matching to ensure optimal sound quality.

The ability to use the audio system to charge devices connected to it – pocket audio players, mobile phones, etc. For this usually a USB port is used (microUSB or USB-C in modern models); some models are able to play music from an external gadget right in the process of charging.