An affordable AV receiver is always a good option to consider, so Denon AVR-X6500H vs Onkyo TX-NR555 comparison definitely makes sense.
A significant difference between the receivers in the number of channels, Denon AVR-X6500H has 11.2 versus 7.2 for Onkyo TX-NR555. Regarding power, then AVR-X6500H has such a W/Ohm ratio - 140/8, 175/6 when TX-NR555 has a power of 130/6. The THD is 0.05% for the AVR-X6500H but 0.08% for the TX-NR555.
Characteristics of digital to analog converter (DAC) are different, 192 KHz/32-bit for AVR-X6500H and Hi-Grade 384 KHz/32-bit for the TX-NR555. Both the AVR-X6500H and the TX-NR555 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 Denon AVR-X6500H has support for AirPlay, AirPlay 2, and its competitor in our comparison - AirPlay. Spotify can be used on each receiver. The AVR-X6500H can work with the audio stream from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, Mood Mix, and the TX-NR555 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 AVR-X6500H can scale the input HDMI signal, unlike the TX-NR555. Dolby Vision technology found support only on the AVR-X6500H.
The Denon AVR-X6500H has 8/3 HDMI inputs/outputs versus 6/1 HDMI connectors of the Onkyo TX-NR555. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVR-X6500H. 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 AVR-X6500H supports 3 Multi-room zones, versus 2 for the TX-NR555. It is also worth noting that the ECO mode is presented in each of the receivers. The setup assistant will help you configure Denon AVR-X6500H.
Both devices have support for Dolby Atmos multichannel audio format. The surround sound technology DTS:X is supported by devices under review.