It makes sense comparing Denon AVR-X8500H vs Denon AVR-X4500H because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Denon AVR-X8500H has 13.2 versus 9.2 for Denon AVR-X4500H. Regarding power, then AVR-X8500H has such a W/Ohm ratio - 150/8, 250/6 when AVR-X4500H has a power of 125/8, 165/6. The THD is the same and is 0.05%.
Characteristics of digital to analog converter (DAC) are different, AK4490EQ 768 KHz/32-bit for AVR-X8500H and AK4458 384 KHz/32-bit for the AVR-X4500H. Both the AVR-X8500H and the AVR-X4500H support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Both models have the ability to connect to the Internet via WI-FI. 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. Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud - all of these streaming services have found application in each of the models. 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.
Each receiver has 8/3 HDMI inputs/outputs. 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-X8500H supports voice control via Amazon Alexa, Google Assistant, Siri, Josh.AI, and the AVR-X4500H - Amazon Alexa. It is also worth noting that the ECO mode is presented in each of the receivers. Both AVR-X8500H and AVR-X4500H 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.