The Denon AVR-S640H vs Denon AVR-S930H comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Denon AVR-S640H has 5.2 versus 7.2 for Denon AVR-S930H. Regarding power, then AVR-S640H has such a W/Ohm ratio - 75/8, 100/6 when AVR-S930H has a power of 90/8, 125/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for AVR-S640H and 192 KHz/24-bit for the AVR-S930H. None of the models 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. The AVR-S640H can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, and the AVR-S930H can receive a content from Deezer, TIDAL, Pandora,iHeart Radio, Sirius XM, Sound Cloud, Napster.
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 AVR-S930H can scale the input HDMI signal, unlike the AVR-S640H. The HDR standard - Dolby Vision is supported by these receivers.
The Denon AVR-S640H has 5/1 HDMI inputs/outputs versus 8/2 HDMI connectors of the Denon AVR-S930H. 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 AVR-S640H has a built-in phono stage for connecting a vinyl player. Supported voice control technologies are identical - Amazon Alexa, Google Assistant, Siri, Josh.AI. It is also worth noting that the ECO mode is presented in each of the receivers. Both AVR-S640H and AVR-S930H can be configured using the Setup assistant.
Only the AVR-S930H has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the AVR-S930H.