Comparison Onkyo TX-RZ840 vs Denon AVR-X4500H

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.

This function automatically adjusts the volume level of the sound when it changes abruptly. Such a need is associated, for example, with the fact that one film can contain both dialogue and intense special effects; as a result, at low volume, conversations can sometimes be hard to hear, and at high volume, the sound can periodically “beat on the ears” and disturb others. In addition, while watching TV, many have probably come across commercials that sound noticeably louder than the main programme. Automatic level control boosts the volume at low audio levels and lowers it at high levels, thus helping to avoid the discomfort of too loud sound while maintaining normal hearing.

The audio receiver supports eARC, an enhanced version of the Audio Return Channel (ARC) used with an HDMI connection (see below).

By itself, the audio return channel allows you to "swap" the HDMI output of the AV receiver and the HDMI input of the TV or other external device — thus, this device turns into an audio signal source, and the receiver starts to work as a receiver. Such functionality is designed mainly for those cases when the TV receives a signal not from the receiver, but from another source (built-in tuner, media player, flash drive, etc.), however, the soundtrack must be output to external speakers through the receiver. Without ARC, you would have to use an additional connection (for example, via an optical interface), while the audio return channel eliminates the need for extra wires: the same HDMI cable is used both for transmitting video / audio from the receiver to the TV and for transmitting audio from TV to receiver. Also, the advantages of ARC over traditional audio interfaces are higher bandwidth, as well as the ability to use the CEC function (control of connected devices from one remote control).

Specifically, eARC was introduced simultaneously with the HDMI 2.1 standard and received a number of improvements compared to conventional ARC. Here are the main ones:

— Up to 40x more bandwidth, allowing uncompressed 5.1 and 7.1 surround sound, HD audio and Dolby Atmos and DTS:X "object-orie...nted" multi-channel codecs (see Decoders).
— Technology Lip Sync Correct, eliminating desynchronization between video and sound.
— Proprietary protocol to automatically detect audio formats supported by both connected devices and select the best option.

Of course, in order to use eARC, both the receiver and the TV it is connected to must support it.

the maximum sound power that can be delivered by the power amplifier (if the receiver has one, see "Type") per speaker channel. It is worth noting here that in this case it is customary to indicate the so-called RMS (Rated Maximum Sinusoidal), or rated power. Rated is considered the highest power that the amplifier is guaranteed to be able to produce without interruption for an hour without any failures or breakdowns. Short-term jumps in the signal level can significantly exceed this value, but the main indicator is still the rated power.

The power of the amplifier largely determines the sound volume of the speaker system connected to the device. In fact, the loudness also depends on the characteristics of the speakers — sensitivity, impedance, etc.; however, other things being equal, the same acoustics on a more powerful amplifier will sound louder. In addition, this parameter also affects the compatibility of the speakers and the amplifier — it is believed that the difference in the nominal powers of these components should not exceed 10-15% (and ideally, the powers should generally match). And since different rooms require speakers of different power, this also affects the choice of amplifier for a particular environment; specific recommendations on the ratio of room characteristics and acoustic power can be found in special sources.

Also note that if the amplifier can operate with a load of different resistance (see..."Permissible acoustic impedance"), then for different options the power per channel will be different — the lower the resistance, the higher the power. In the characteristics, in this case, the maximum value of this parameter is usually indicated — that is, the power at the minimum allowable resistance.

This indicator determines the amount of extraneous noise that accompanies the sound output by the receiver's amplifier. It is convenient because it takes into account almost all possible significant noise — both created by the device itself and due to external causes. The higher the signal-to-noise ratio, the lower the noise volume compared to the main signal, the cleaner the amplifier will sound. A reading of 70-80 dB is considered normal for most consumer electronics, but in AV receivers, which are usually premium devices, this can only be called satisfactory. In the most advanced models, this figure can significantly exceed 100 dB.

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.

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.

Audio and video file formats that the receiver is capable of playing on its own. Models with player features generally support most popular media file types (particularly AVI, MPEG and MKV for video, MP3, WAV and WMA for audio), but the file set may have its own peculiarities. This item allows you to find out.

- AirPlay. Technology for transmitting multimedia data via a wireless connection ( Wi-Fi). Developed by Apple, it is intended mainly for broadcasting content from various Apple devices (primarily portable gadgets) to compatible external devices. Allows you to transfer audio files (in audio streaming mode, see “Tuner and playback” for more details), as well as images, text data and even video. The presence of AirPlay in the receiver will allow you to connect Apple equipment with support for this technology to it for direct playback, as well as display information about files on an external screen (for example, a TV) - song name, artist name, etc.

- AirPlay 2. The second version of the AirPlay technology described above, released in 2018. One of the main innovations introduced in this update was support for the multi-room format - the ability to simultaneously broadcast several separate audio signals to different compatible devices installed in different locations. Thus, you can, for example, turn on the next episode of your favorite series from your iPhone on the TV in the living room, and relaxing music from your iPod in the kitchen, etc. In addition, AirPlay 2 received a number of other improvements - improved buffering, the ability to stream to stereo acoustics, as well as support for voice control via Siri.

- Chromecast.... Original name: Google Cast. Technology for broadcasting content to external devices, developed by Google. Allows you to transmit video and audio from a PC or mobile device to the AV receiver; broadcasting is usually carried out via Wi-Fi, while the receiver and the signal source must be on the same Wi-Fi network (with the exception of Chromecast media players). Chromecast technology supports two modes - actual broadcasting through special applications (available for Windows, macOS, Android and iOS) and “mirroring” content opened in the Google Chrome browser on an external screen.

- Wi-Fi. A wireless interface used primarily for building computer networks. Accordingly, AV receivers may need its presence primarily to implement network functions - streaming audio, Internet radio (see “Tuner and playback”), AirPlay (see above), DLNA (see below). Connecting to computer networks can also be done through a wired LAN interface(see below), but Wi-Fi is more convenient due to the absence of wires and the ability to work through obstacles (including walls) at a distance of several tens of meters. In addition, in some models, this technology can also be used to communicate directly with other devices - for example, to use a smartphone or tablet as a remote control, or to broadcast live video using Miracast technology or another similar format.

— Bluetooth. Direct wireless communication technology between various electronic devices; operates at a range of about 10 m, although some specific operating formats provide a longer range. Technically, it can be used for different purposes, depending on the protocols supported by a particular device; In AV receivers, two protocols are most often found - A2DP for wireless broadcasting of audio signals and AVRCP for remote control. In the first case, we are usually talking about transmitting a signal from an external device (smartphone, laptop, etc.) to the receiver; theoretically, the opposite option is also possible - broadcasting sound to Bluetooth headphones or acoustics, however, for a number of reasons, this format of operation is almost never found in AV receivers. AVRCP, in turn, allows you to use an external gadget (for example, the same smartphone) as a remote control.

- LAN. A standard interface for wired connection of various equipment (including AV receivers) to computer networks, incl. to access the Internet. Due to the presence of a wire, it is less convenient to connect than the Wi-Fi described above. On the other hand, a LAN connection wins in terms of connection reliability and actual data transfer speed - especially if there are many wireless devices on the network and Wi-Fi channels are busy (which is often the case, since Wi-Fi modules are very popular in modern electronics ). Therefore, for working with large volumes of data - for example, watching high-definition video via DLNA (see below) - LAN is better suited.

— RS-232. A wired interface that originally appeared in computer technology. In AV receivers, it can be called a service connector: content is not transmitted through this connector, but through it you can connect the device to a computer and remotely change settings, as well as update the firmware.

— MHL. High-speed wired interface for transmitting multimedia data (video and audio) from mobile devices to external screens. The bandwidth allows you to work with high or even ultra-high resolution images, as well as multi-channel audio. Also, when connected, the gadget can be charged. In mobile devices, the MHL signal is output via a standard microUSB port; and the role of the input in AV receivers (and other stationary equipment) is played by the HDMI connector (see below) - however, not every connector, but only one that is initially compatible with MHL and has the appropriate marking. Adapters are available for connecting to regular HDMI, but additional functions (like charging) may not be available with this connection.

- DLNA. A technology used to connect various electronic devices into a single digital network with the ability to directly exchange content. Devices for which support for this standard is declared are able to communicate effectively regardless of the manufacturer. An AV receiver with DLNA can, for example, play a movie directly from the hard drive of a computer in the next room, or transfer photos from a smartphone to the TV. Connecting to the Network can be done either wired (LAN) or wirelessly (Wi-Fi, see above).

- Roon Tested. Roon Tested accreditation means the AV receiver is compatible with the popular audiophile music streaming platform Roon. Certified models have undergone a series of tests and meet the quality standards required to operate Roon flawlessly. This ensures convenient management and organization of content within the platform.

— Coordination of Remote control. A function that allows you to connect the AV receiver to another device (for example, a Blu-ray player or external amplifier) and control both devices with one remote control. When purchasing equipment with such a function, it is necessary to clarify compatibility - as a rule, only equipment from one manufacturer can work in such a “bundle”, and even in such cases, their own nuances are possible upon agreement.

— Voice assistant. Receiver support for voice assistant. The most popular assistants these days are:

• Google Assistant
• Apple Siri
  
• Amazon Alexa

However, other solutions may also emerge. In any case, it is worth noting that we are not talking about an assistant built into the receiver itself, but about compatibility with external devices that have this function (for example, a smartphone or tablet). But even such compatibility allows you to give commands to the receiver by voice - this is often more convenient than more traditional control methods. The specific set of supported commands and languages may vary depending on the voice assistant and its specific version.