An affordable AV receiver is always a good option to consider, so Denon AVR-S540BT vs Onkyo TX-SR393 comparison definitely makes sense.
Considered AV receivers have the same number of channels 5.2. Regarding power, then AVR-S540BT has such a W/Ohm ratio - 70/8, 90/6 when TX-SR393 has a power of 80/8, 155/6. The THD is the same and is 0.08%.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for AVR-S540BT and AKM 384 KHz/32-bit for the TX-SR393. None of the models support Bi-amping. Sound transmission directly to the amplifier in Pure direct (straight) mode is not implemented in these models.
Both models do not have WI-FI support. Rivals from our review have Bluetooth support. Each of these units does not support Apple Music. Only the AVR-S540BT supports Spotify. 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 TX-SR393 can scale the input HDMI signal, unlike the AVR-S540BT. The HDR standard - Dolby Vision is supported by these receivers.
The Denon AVR-S540BT has 5/1 HDMI inputs/outputs versus 4/1 HDMI connectors of the Onkyo TX-SR393. 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. Receivers do not have 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.
Only the TX-SR393 has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the TX-SR393.