It makes sense comparing Denon AVRS730H vs Onkyo TX-RZ710 because they both are able to give some premium features.
Considered AV receivers have the same number of channels 7.2. Regarding power, then AVRS730H has such a W/Ohm ratio - 75/8, 110/6 when TX-RZ710 has a power of 175/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, 384 KHz/32-bit for AVRS730H and AK4458 384 KHz/32-bit for the TX-RZ710. Only the TX-RZ710 supports Bi-amping feature. The Onkyo TX-RZ710 can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. The Denon AVRS730H has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The AVRS730H can work with the audio stream from Deezer, TIDAL, iHeart Radio, Sirius XM, Sound Cloud, Napster, 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. The TX-RZ710 can scale the input HDMI signal, unlike the AVRS730H. Dolby Vision technology found support only on the AVRS730H.
The Denon AVRS730H has 6/1 HDMI inputs/outputs versus 8/2 HDMI connectors of the Onkyo TX-RZ710. The HDMI Audio Return Channel (ARC) feature supports both devices. Unfortunately, HDMI eARC is not available on monitored devices. 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. The TX-RZ710 has a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. It is also worth noting that the ECO mode is presented in each of the receivers. The setup assistant will help you configure Denon AVRS730H.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.