It makes sense comparing Pioneer SC-LX901 vs Denon AVR-X4400H because they both are able to give some premium features.
Considered AV receivers have the same number of channels 11.2. Regarding power, then SC-LX901 has such a W/Ohm ratio - 140/8, 200/6 when AVR-X4400H has a power of 125/8, 165/6. The THD is 0.08% for the SC-LX901 but 0.05% for the AVR-X4400H.
Characteristics of digital to analog converter (DAC) are different, ESS SABRE32 Ultra 192 KHz/32-bit for SC-LX901 and AK4458 384 KHz/32-bit for the AVR-X4400H. Both the SC-LX901 and the AVR-X4400H 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 Pioneer SC-LX901 has support for AirPlay, and its competitor in our comparison - AirPlay, AirPlay 2. Spotify can be used on each receiver. The SC-LX901 can work with the audio stream from Deezer, TIDAL, Pandora, TuneIn Radio, and the AVR-X4400H can receive a content from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud.
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. The HDR standard - Dolby Vision is supported by these receivers.
The Pioneer SC-LX901 has 8/2 HDMI inputs/outputs versus 8/3 HDMI connectors of the Denon AVR-X4400H. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVR-X4400H. 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. An ECO mode is only available for the AVR-X4400H. Both SC-LX901 and AVR-X4400H 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.