The Denon AVR-S650H vs Denon AVR-X4100W comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Denon AVR-S650H has 5.2 versus 7.2 for Denon AVR-X4100W. Regarding power, then AVR-S650H has such a W/Ohm ratio - 75/8, 100/6 when AVR-X4100W has a power of 125/8, 165/6. The THD is 0.08% for the AVR-S650H but 0.05% for the AVR-X4100W.
Characteristics of digital to analog converter (DAC) are different, AKM 192 KHz/32-bit for AVR-S650H and 192 KHz/24-bit for the AVR-X4100W. Only the AVR-X4100W supports Bi-amping feature. 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 Denon AVR-S650H has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The AVR-S650H can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, Mood Mix, and the AVR-X4100W can receive a content from Pandora, SiriusXM. 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-X4100W can scale the input HDMI signal, unlike the AVR-S650H. The HDR standard - Dolby Vision is supported by these receivers.
The Denon AVR-S650H has 5/1 HDMI inputs/outputs versus 8/3 HDMI connectors of the Denon AVR-X4100W. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVR-S650H. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. These compared receivers have a built-in phono stage for connecting a vinyl player. It is also worth noting that the ECO mode is presented in each of the receivers. Both AVR-S650H and AVR-X4100W can be configured using the Setup assistant.
Only the AVR-X4100W has a Dolby Atmos multichannel audio format support. The receivers do not support the surround sound technology DTS:X.