Denon AVR-X4500H vs Onkyo TX-RZ920 comparison definitely makes sense.
Considered AV receivers have the same number of channels 9.2. Regarding power, then AVR-X4500H has such a W/Ohm ratio - 125/8, 165/6 when TX-RZ920 has a power of 135/8, 175/6. The THD is 0.05% for the AVR-X4500H but 0.04% for the TX-RZ920.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for AVR-X4500H and AK4490 384 KHz/32-bit for the TX-RZ920. Both the AVR-X4500H and the TX-RZ920 support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay, AirPlay 2. Spotify can be used on each receiver. The AVR-X4500H can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, and the TX-RZ920 can receive a content from Deezer, TIDAL, Pandora, TuneIn Radio.
Both AV receivers support HDR10 technology (High dynamic range). Compared AV receivers retain the quality of 4K/60Hz signal when transmitting from a source to a TV or projector. HDMI signal transmission in standby mode is implemented in each of the devices. Both rivals can scale the resolution of the incoming HDMI signal. The HDR standard - Dolby Vision is supported by these receivers.
The Denon AVR-X4500H has 8/3 HDMI inputs/outputs versus 8/2 HDMI connectors of the Onkyo TX-RZ920. The HDMI Audio Return Channel (ARC) feature supports both devices. HDMI eARC is available in each model. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. Both models support the standard HDCP 2.2. These compared receivers have a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 3 Multi-room zones. The AVR-X4500H supports voice control via Amazon Alexa, and the TX-RZ920 - Google Assistant. An ECO mode is only available for the AVR-X4500H. Both AVR-X4500H and TX-RZ920 can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.