It makes sense comparing Marantz NR1608 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 NR1608 has such a W/Ohm ratio - 50/8, 70/6 when TX-RZ710 has a power of 175/6. The THD is 0.05% for the NR1608 but 0.08% for the TX-RZ710.
Competitors' digital to analog converter (DAC) is identical to AK4458 384 KHz/32-bit. Both the NR1608 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.
WI-FI modules have the same characteristics: 2.4/5GHz. Rivals from our review have Bluetooth support. The Marantz NR1608 has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The NR1608 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 NR1608.
The Marantz NR1608 has 8/1 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 Marantz NR1608.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.