It makes sense comparing Denon AVR-X6400H vs Onkyo TX-RZ710 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Denon AVR-X6400H has 11.2 versus 7.2 for Onkyo TX-RZ710. Regarding power, then AVR-X6400H has such a W/Ohm ratio - 140/8, 250/6 when TX-RZ710 has a power of 175/6. The THD is 0.05% for the AVR-X6400H but 0.08% for the TX-RZ710.
Competitors' digital to analog converter (DAC) is identical to AK4458 384 KHz/32-bit. Both the AVR-X6400H and the TX-RZ710 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 Denon AVR-X6400H has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The AVR-X6400H can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, and the TX-RZ710 can receive a content from Deezer, TIDAL, Pandora, Tunein Radio.
These units support HDR technology. 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. Dolby Vision technology found support only on the AVR-X6400H.
The Denon AVR-X6400H has 8/3 HDMI inputs/outputs versus 8/2 HDMI connectors of the Onkyo TX-RZ710. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVR-X6400H. 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.
The AVR-X6400H supports 3 Multi-room zones, versus 2 for the TX-RZ710. It is also worth noting that the ECO mode is presented in each of the receivers. The setup assistant will help you configure Denon AVR-X6400H.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.