DAC frequency
A digital-to-analogue converter (DAC) is an indispensable element of any system designed to reproduce digital sound. The DAC is an electronic module that translates sound information into pulses that are sent to the speakers. The technical features of such a conversion are such that the higher the sampling frequency, the better the signal at the output of the DAC, the less it is distorted during conversion. The most popular option in receivers today is 192 kHz — it corresponds to a very high sound quality (DVD-Audio) and at the same time avoids unnecessary increase in the cost of devices.
HDR
Receiver support for
HDR technology; this clause may also specify the specific supported HDR format.
HDR stands for High Dynamic Range. This technology allows you to expand the range of brightness reproduced simultaneously on the screen; to put it simply, the viewer will see brighter whites and darker blacks. In practice, this means a significant improvement in color quality: colors are more vibrant and at the same time more faithful than without HDR. However, to use this function, in addition to the receiver, a TV/projector that supports the appropriate HDR format and content recorded in this format is required.
In terms of specific formats, the most popular options these days are basic HDR10, advanced HDR10+, and high-end
Dolby Vision. Here are their features:
- HDR10. Historically the first of the consumer HDR formats, less advanced than the options described below but extremely widespread. In particular, HDR10 is supported by almost all streaming services that provide HDR content at all, and it is also common for Blu-ray discs. Allows you to work with a color depth of 10 bits (hence the name). At the same time, devices of this format are also compatible with content in HDR10 +, although its quality will be limited by the capabilities of the original HDR10.
- HDR10+. Improved version of HDR10. With the same color depth (10 bits), it uses the so-called dynamic metadata,
...which allows transmitting information about the color depth not only for groups of several frames, but also for individual frames. This results in an additional improvement in color reproduction.
Dolby Vision. An advanced standard used particularly in professional cinematography. Allows you to achieve a color depth of 12 bits, uses the dynamic metadata described above, and also makes it possible to transmit two image options at once in one video stream - HDR and normal (SDR). At the same time, Dolby Vision is based on the same technology as HDR10, so in modern video technology this format is usually combined with HDR10 or HDR10+.HDMI version
HDMI interface version supported by the receiver. Usually, all HDMI connectors available in the device correspond to this version — both inputs (see above) and outputs (see below). Here are the current options:
— v 1.4. The oldest of the current versions, released in 2009. However, it supports 3D video capable of working with resolutions up to 4096x2160 at 24 fps, and in Full HD resolution, the frame rate can reach 120 fps. In addition to the original v.1.4, there are also improved modifications — v.1.4a and v.1.4b; they are similar in terms of basic features, in both cases the improvements affected mainly work with 3D content.
-v 2.0. Significant update to HDMI introduced in 2013. In this version, the maximum frame rate in 4K has increased to 60 fps, and the audio bandwidth has increased to 32 channels and 4 separate streams simultaneously. Also from the innovations, we can mention support for the ultra-wide format 21:9. In the v.2.0a update, HDR support was added to the interface capabilities, in v.2.0b this feature was improved and expanded.
— v 2.1. Despite the similarity in name to v.2.0, this version, released in 2017, was a very large-scale update. In particular, it added support for 8K and even 10K at speeds up to 120 fps, as well as further expanded the possibilities for working with HDR. Under this version, its own cable was released — HDMI Ultra High Speed, all v.2.1 features are available only when using cables of this standard,...although basic functions can be used with simpler cords.
Smartphone control
Ability to control the AV receiver
from a portable device. Note that this can be not only a smartphone, but also any other gadget that is compatible with a special control application — for example, a tablet. Connection with such a "remote control" is carried out via the wireless standard Wi-Fi or Bluetooth (see "Interfaces"). This allows you to control the device even through walls, while classic remote controls use the infrared channel and work only in the line of sight. In addition, the functionality of the control application can be almost unlimited, and the manufacturer can also update it by adding new features.
