Comparison Onkyo TX-SR3100 vs Onkyo TX-NR6100

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.

Another indicator that determines the overall quality of the digital-to-analogue audio converter. For details on the converter, see "Audio DAC Sampling Rate"; here we note that the bit depth is standardly expressed in bits, and the higher it is, the more accurately the signal at the output of the DAC corresponds to the original signal and the less distortion is introduced into it. Today, it is believed that a 16-bit indicator provides quite acceptable signal quality, and 24-bit DACs are suitable even for premium-level equipment.

The ability to increase the resolution of the video signal processed by the receiver - if the original video resolution is lower. Depending on the capabilities of the receiver, in particular its HDMI ports, upscaling to Ultra HD 4K and upscaling to Ultra HD 8K may occur.

The principle of upscaling is that a relatively low-resolution video is supplemented with the required number of pixels using special algorithms. Due to this, when playing such a video, the quality of the “picture” is noticeably higher than without upscaling (although somewhat lower than that of content originally recorded in UltraHD). It makes sense to specifically look for a receiver with this function if you plan to use it with a 4K or 8K screen.

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+.

The ability of the receiver to output a video signal in 3D format — that is, a "volumetric" image that has three full dimensions (including depth). Since 3D uses the division of the “picture” of the image into two parts (for the left and right eyes), the format of such a signal differs from the usual two-dimensional one, and not every model is able to work with it. Also keep in mind that viewing 3D content requires not only a receiver, but also a TV (or other playback device) with the appropriate screen capabilities.

The range of sound frequencies that the receiver is capable of outputting (this parameter can also be specified for models without their own amplifier, see “Number of channels” for more details). The completeness of the transmitted sound depends on this parameter; of course, the sound quality in general is highly dependent on a number of other factors (for example, frequency response), but the wider the frequency range, the less risk that the amplifier will completely “cut off” some part of the sound. On the other hand, it should be taken into account here that the normal hearing range of the human ear is approximately 16 – 20,000 Hz, and deviations from these limits are rather small. And although many modern receivers provide a much wider frequency range, however, this is more of a marketing ploy than a really significant indicator (or some kind of "side defect" in the design of a high-quality amplifier).

It is also worth considering that in order to reproduce the full frequency of the amplifier, you will need speakers with the appropriate characteristics.

The ability of the receiver to work in Bi-amping and/or Tri-amping mode.

The basic principle of both of these modes is that the audio signal is divided into several frequency bands (LF and HF for Bi-amping, in the case of Tri-amping, mid frequencies are separated separately), and each band is processed by its own amplifier and output to its own specialized set of speakers. . In this way, a noticeable improvement in sound quality can be achieved. However, note that the specific implementation of this function in AV receivers may be different. The simplest option involves two or three built-in power amplifiers, each of which outputs the entire audio range to its own set of connectors. To such a device, you need to connect an external crossover (frequency filter) or speakers with built-in filters for each frequency band. More advanced receivers may have their own built-in crossovers, in which case only part of the frequency range is output to each amplifier with a set of connectors; this eliminates the need for external frequency filters. However, anyway, to use Bi/Tri-amping, you will need speakers that support this connection format.

— AM/FM radio. The presence of a built-in tuner that allows you to receive AM and FM radio broadcasts without additional devices (except perhaps an antenna is required, and then not always). In FM, it is possible to realize the transmission of high-quality stereo sound, however, the waves propagate only within the line of sight (10-20 km); therefore, most of the stations in this range are classified as "urban music". In AM, the transmission range is already measured in hundreds of kilometers, but the sound quality is noticeably lower; therefore, such stations usually specialize in talk programs (particularly news).

— USB stick. The ability to connect a USB drive to the receiver — for example, a "flash drive" or an external hard drive — and play content from it directly. This requires a USB connector. Most often, in models with this function, it is located on the front panel (see below) — this provides ease of connection; at the same time, there are exceptions. Also note that the very presence of USB does not necessarily imply the possibility of playing from external media — this interface can be used for service purposes, for example, to update the firmware or play from a PC (see "Advanced (inputs) — USB Type B").

— Network audio streaming. The ability to play streaming audio over a local network or the Internet (including from services like Grooveshark o...r Last.Fm). The name "streaming" is due to the fact that each song is played directly from the network, without being written to the receiver's own permanent storage. This function, by definition, requires connection to computer networks; most often, a Wi-Fi module is used for this purpose (see "Interfaces") or a LAN connector.

— Internet radio. The ability to use the receiver to receive and play Internet radio broadcasts. This feature is similar in many ways to the network audio described above — in particular, it requires a network connection to work, and the data is streamed; however, in the case of network audio, the user himself chooses what and when to listen, here the broadcast is similar to conventional radio transmissions and is controlled from the radio station. Actually, many major stations broadcast their programs not only on the traditional air, but also via the Internet; There are also specialized projects broadcasting only on the Web. In general, the choice of programs is much more extensive than for conventional radio broadcasting — after all, Internet radio has no range restrictions. And the receivers themselves may provide additional tools for managing such broadcasting — for example, catalogs, search by genres, languages, etc.

A set of streaming services supported by the AV receiver.

Such services are designed for streaming audio content over the Internet. In this case, the files are not saved to the device, but are played directly from the corresponding resource on the global network. Streaming services allow you to access vast libraries of music without having to take up your device's internal storage. The key advantages of online streaming include a huge selection of content and almost instant access to the desired audio tracks. Popular ones include Amazon Music, Deezer, SoundCloud, Spotify, TIDAL, YouTube Music.