The Onkyo TX-NR646 vs Pioneer SC-LX801 comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Onkyo TX-NR646 has 7.2 versus 9.2 for Pioneer SC-LX801. Regarding power, then TX-NR646 has such a W/Ohm ratio - 160/6 when SC-LX801 has a power of 140/8, 200/6, 255/4. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, Hi-Grade 384 KHz/32-bit for TX-NR646 and ESS SABRE32 Ultra 192 KHz/32-bit for the SC-LX801. Both the TX-NR646 and the SC-LX801 support Bi-amping. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Rivals from our review have Bluetooth support. The Apple Music service is implemented on considered devices: AirPlay. Spotify can be used on each receiver. The TX-NR646 can work with the audio stream from Deezer, TuneIn Radio, and the SC-LX801 can receive a content from Deezer, TIDAL, Pandora. 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 SC-LX801 can scale the input HDMI signal, unlike the TX-NR646. Dolby Vision technology found support only on the SC-LX801.
Each receiver has 8/2 HDMI inputs/outputs. 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. These compared receivers have a built-in phono stage for connecting a vinyl player.
The TX-NR646 supports 2 Multi-room zones, versus 3 for the SC-LX801. A voice control is not available. An ECO mode is only available for the TX-NR646. Both TX-NR646 and SC-LX801 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.