The Denon AVR-S940H vs Denon AVR-X4100W comparison proves that these receivers have many common features.
Considered AV receivers have the same number of channels 7.2. Regarding power, then AVR-S940H has such a W/Ohm ratio - 90/8, 125/6 when AVR-X4100W has a power of 125/8, 165/6. The THD is 0.08% for the AVR-S940H but 0.05% for the AVR-X4100W.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for AVR-S940H 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-S940H has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The AVR-S940H can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, 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. Both rivals can scale the resolution of the incoming HDMI signal. The HDR standard - Dolby Vision is supported by these receivers.
The Denon AVR-S940H has 8/2 HDMI inputs/outputs versus 8/3 HDMI connectors of the Denon AVR-X4100W. 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. These compared receivers have a built-in phono stage for connecting a vinyl player.
The AVR-S940H supports 2 Multi-room zones, versus 3 for the AVR-X4100W. It is also worth noting that the ECO mode is presented in each of the receivers. Both AVR-S940H and AVR-X4100W can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. A surround technology DTS:X is supported only by the AVR-S940H.