Having had an opportunity to test Denon AVR-X6400H vs Denon AVR-X3700H, I’d like to share my impression here to facilitate your choice of a new AV receiver.
The number of channels for receivers is different - 11.2 versus 9.2, respectively, for devices. In terms of power, there are differences, the AVR-X6400H has such a ratio W/Ohm - 140/8, 250/6, while the AVR-X3700H has a power of 105/8, 135/6. The value of total harmonic distortion is also different, and for the AVR-X6400H it is 0.05%, but for the AVR-X3700H it is 0.08%. Each of the compared opponents supports Bi-amping. Both Denon AVR-X6400H and Denon AVR-X3700H can transmit an audio signal directly to the amplifier and bypasses any DSP processing. Each of the receivers has a Bluetooth connector. Both devices can work with such Apple Music services: AirPlay, AirPlay 2. Access to the Spotify service is on each of the competitors. The number of available streaming services varies for receivers, the Denon AVR-X6400H works with Deezer, TIDAL, Pandora, Napster, SiriusXM, TuneIn Radio, iHeart Radio, Sound Cloud, but the Denon AVR-X3700H works with Deezer, TIDAL, Pandora, SiriusXM, Qobuz, TuneIn Radio. Signaling over HDMI in standby mode can provide the AVR-X6400H and the AVR-X3700H. Each of the devices can increase the resolution of the incoming video signal. Each of the participants of the comparison has a Dolby Vision.
The number of HDMI inputs/outputs varies depending on the receiver, the AVR-X6400H has 8/3, and the AVR-X3700H has 7/3. HDMI Audio Return Channel is implemented in both devices. HDMI eARC is supported by the AVR-X6400H and the AVR-X3700H. When comparing receivers, it becomes clear that each of the rivals can work with HDMI CEC. The AVR-X6400H has support for the standard HDCP 2.2, compared to the AVR-X3700H, which supports the standard HDCP 2.3. Like most receivers, our models have a built-in phono stage for connecting a vinyl player.
Unlike the AVR-X6400H where 3 Multi zones is provided, the AVR-X3700H works with 2 Multi zones. Voice control is performed using Amazon Alexa, Google Assistant, Siri, Josh.AI in both models. There is an ECO mode in either AV receiver. The Denon AVR-X6400H and the Denon AVR-X3700H can be properly configured using the setup assistant.
A Dolby Atmos multichannel audio format is available both models. A DTS:X surround technology is supported by devices from our comparison.