It makes sense comparing Yamaha RX-V671 vs Denon AVR-S950H because they both are able to give some premium features.
A significant difference between the receivers in the number of channels, Yamaha RX-V671 has 7.1 versus 7.2 for Denon AVR-S950H. Regarding power, then RX-V671 has such a W/Ohm ratio - 90/8, 150/4 when AVR-S950H has a power of 90/8, 125/6. The THD is 0.09% for the RX-V671 but 0.08% for the AVR-S950H.
Characteristics of digital to analog converter (DAC) are different, Burr-Brown 192 KHz/24-bit for RX-V671 and AKM 192 KHz/32-bit for the AVR-S950H. Only the RX-V671 supports Bi-amping feature. Each of the AV receivers can transmit an audio signal directly to the amplifier and bypasses any DSP processing.
Only the Denon AVR-S950H can connect to the Internet via WI-FI. Rivals from our review have Bluetooth support. Only the AVR-S950H supports Spotify. The RX-V671 can work with the audio stream from Napster, and the AVR-S950H can receive a content from Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, Mood Mix. 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. Both rivals can scale the resolution of the incoming HDMI signal. Dolby Vision technology found support only on the AVR-S950H.
The Yamaha RX-V671 has 6/1 HDMI inputs/outputs versus 8/2 HDMI connectors of the Denon AVR-S950H. The HDMI Audio Return Channel (ARC) feature supports both devices. The HDMI eARC is available only on the AVR-S950H. The Consumer Electronics Control (CEC) feature is present in most modern AV receivers and the models in our comparison are no exception. The RX-V671 supports the protection of digital content of the standard HDCP 2.2, versus HDCP 2.3 in the AVR-S950H. These compared receivers have a built-in phono stage for connecting a vinyl player.
Each of the AV receivers from our review supports 2 Multi-room zones. An ECO mode is only available for the AVR-S950H. The setup assistant will help you configure Denon AVR-S950H.
Only the AVR-S950H has a Dolby Atmos multichannel audio format support. A surround technology DTS:X is supported only by the AVR-S950H.