Onkyo TX-NR646 Review

Onkyo has always been at the forefront when it comes to adopting and implementing new technology and features in their latest products. They were one of the first to add HDCP 2.2 and Dolby Atmos, and once again they lead the way by adding the latest Immersive Surround Sound formats to the new TX-NR646 7.2-Ch Network A/V Receiver - in this case DTS:X. All that is missing in this very affordable model is the Auro-3D format.

​In short, no major changes compared to the previous model, apart from some added connectivity and improved digital-to-analog conversion. Oh, and DTS:X of course.

The AccuEQ room acoustic calibration has been improved as well as it now implements equalization on the front speakers, something we missed in the previous model. The measurements are still being made using only one position, but it's not a major issue at this relatively modest price, especially since the AccuEQ lives up to its name and actually include an EQ for the different speaker groups - including the subwoofer(!). It's a useful, although limited, 5-band EQ that can be adjusted in steps between -6dB and +6dB. The speaker terminals offer some flexibility and allows you to choose between traditional setups (2.0 up to 7.2), more immersive setups including Height Speakers, and Zone 2 and bi-amping.

The new features are also represented in the on-screen menus, which still looks typically Onkyo, meaning fairly well structured, easy to navigate and intuitive, but also a bit dull to look at. The remote control is pretty much the same as previously but with some minor changes. It still gets the job done and has clearly laid out buttons, but Onkyo also offers a Remote App (iOS, Android) that combines control and streaming functionality in one easy-to-navigate interface.

​Video and Multimedia Functionality

Audio-wise it supports ​Dolby Atmos, Dolby TrueHD, Dolby Digital Plus, Dolby Digital, DTS:X, DTS-HD Master Audio, DTS-HD High Resolution Audio, DTS 96/24, DTSES, DTS, DTS Express, DSD and Multichannel PCM (up to 8ch).

You can also stream audio wirelessly via bluetooth or Wi-Fi, and it supports Spotify, Pandora, SiriusXM Internet Radio, Slacker and TuneIn. The USB port allows you to play media in FAT16 or FAT32 file system format.

​Sound Quality & Listening Experience

​We started the listening test by setting up the system using the AccuEQ acoustic calibration, and although the system does a decent job we still ended up doing some minor adjustments before we were completely satisfied with the result, and we used a variety of familiar music and movie scenes to get the TX-NR646 to sound as neutral as possible. We also played around with the various listening modes, but as the result ranged from mildly annoying to exceedingly bemused we ultimately decided to turn any unnecessary processing off. Whether you should use the listening modes or apply the EQ or not is a matter of taste and the condition of your listening room, but it's nice to know that you can do any necessary adjustments if needed.

And it does indeed perform. Mad Max: Fury Road can be quite messy at times with a lot of things going on, but the TX-NR646 always managed to keep things under control. Dialog was easily distinguishable and kept from being muddied up by all the background noise, and the soundstage was both wide and deep with easy to pinpoint soundeffects. Sound effects like bullets whizzing over our heads, thunder, wind and sandstorms was presented with authenticity and realism, almost making us believe that we would have to sweep the sand off our listening room floor once we've finished watching the movie.