The Pioneer VSX-LX303 vs Onkyo TX-NR646 comparison proves that these receivers have many common features.
A significant difference between the receivers in the number of channels, Pioneer VSX-LX303 has 9.2 versus 7.2 for Onkyo TX-NR646. Regarding power, then VSX-LX303 has such a W/Ohm ratio - 100/8, 200/6 when TX-NR646 has a power of 160/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, AK4458 384 KHz/32-bit for VSX-LX303 and Hi-Grade 384 KHz/32-bit for the TX-NR646. Both the VSX-LX303 and the TX-NR646 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 VSX-LX303 can work with the audio stream from Deezer, TIDAL, Pandora, TuneIn Radio, and the TX-NR646 can receive a content from Deezer, TuneIn Radio. 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 VSX-LX303 can scale the input HDMI signal, unlike the TX-NR646. Dolby Vision technology found support only on the VSX-LX303.
The Pioneer VSX-LX303 has 7/2 HDMI inputs/outputs versus 8/2 HDMI connectors of the Onkyo TX-NR646. 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 VSX-LX303 supports 3 Multi-room zones, versus 2 for the TX-NR646. An ECO mode is only available for the TX-NR646. Both VSX-LX303 and TX-NR646 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.