It makes sense comparing Denon AVR-S540BT vs Onkyo TX-8020 because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Denon AVR-S540BT has 5.2 versus 2.0 for Onkyo TX-8020. Regarding power, then AVR-S540BT has such a W/Ohm ratio - 70/8, 90/6 when TX-8020 has a power of 90/6. The THD is 0.08% for the AVR-S540BT but 0.03% for the TX-8020.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for AVR-S540BT and 192 KHz/24-bit for the TX-8020. None of the models support Bi-amping. The Onkyo TX-8020 can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Both models do not have WI-FI support. Only the AVR-S540BT has Bluetooth support. Only the AVR-S540BT supports Spotify.
Only the Denon AVR-S540BT has support for High dynamic range (HDR). Only the AVR-S540BT provides HDMI signal transmission in standby mode. Both competitors are not able to scale the HDMI signal. Dolby Vision technology found support only on the AVR-S540BT. Only the AVR-S540BT supports HDMI Audio Return Channel (ARC). Unfortunately, HDMI eARC is not available on monitored devices. Of the two receivers in our comparison, HDMI CEC is present in only the AVR-S540BT. The TX-8020 has a built-in phono stage for connecting a vinyl player. A voice control is not available. An ECO mode is only available for the AVR-S540BT. The setup assistant will help you configure Denon AVR-S540BT.
None of the rivals equipped with Dolby Atmos multichannel audio decoder. The receivers do not support the surround sound technology DTS:X.
The Denon AVR-S540BT is better receiver in this comparison. Check Denon AVR-S540BT price