It makes sense comparing Onkyo TX-NR545 vs Pioneer Elite SC-99 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Onkyo TX-NR545 has 7.2 versus 9.2 for Pioneer Elite SC-99. Regarding power, then TX-NR545 has such a W/Ohm ratio - 100/6 when Elite SC-99 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-NR545 and ESS SABRE 192 KHz/32-bit for the Elite SC-99. Both the TX-NR545 and the Elite SC-99 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 Apple Music service is implemented on considered devices: AirPlay. Spotify can be used on each receiver. The TX-NR545 can work with the audio stream from Tunein Radio, and the Elite SC-99 can receive a content from Pandora.
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. The Elite SC-99 can scale the input HDMI signal, unlike the TX-NR545. The HDR standard - Dolby Vision is not supported by these receivers.
The Onkyo TX-NR545 has 6/1 HDMI inputs/outputs versus 8/3 HDMI connectors of the Pioneer Elite SC-99. The HDMI Audio Return Channel (ARC) feature supports both devices. Unfortunately, HDMI eARC is not available on monitored devices. Of the two receivers in our comparison, HDMI CEC is present in only the TX-NR545. Both models support the standard HDCP 2.2. The Elite SC-99 has a built-in phono stage for connecting a vinyl player.
The TX-NR545 supports 2 Multi-room zones, versus 3 for the Elite SC-99. A voice control is not available. An ECO mode is only available for the Elite SC-99. Both TX-NR545 and Elite SC-99 can be configured using the Setup assistant.
Both devices have support for Dolby Atmos multichannel audio format. The receivers do not support the surround sound technology DTS:X.