Onkyo TX-NR646 review: Powerful, feature-packed receiver amps up the thrills

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13

The Good The fully-loaded Onkyo TX-NR646 delivers cutting-edge technologies such as both Dolby Atmos and DTS-X surround formats, in addition to AirPlay, Wi-Fi and Bluetooth. Its sound quality is excellent for movie replay with exciting sonics and class-leading dynamics. Its superb connectivity includes eight HDMI inputs (one front, seven rear) and two outputs in addition to a phono input.

The Bad The Onkyo TX-NR646's Dolby Atmos height channel capabilities are limited to only the front-left and -right channels, not the surround height channels, and the receiver is only DTS:X "compatible" until an update is released later in 2015. Its external design is generic and bulky, and the user experience isn't helped by its terrible remote and an ancient menu system.

The Bottom Line Considering the Onkyo TX-NR646's generous feature set and superlative sonic skills, it's one heck of a value.

8.0 Overall
  • Design 6
  • Features 9
  • Sound 9
  • Value 8

It is written in the AV bible that the industry "shalt invent a new doohickey every year that compels the buying public to back its wallets up to the till and empty the contents on new gear." Last year that doohickey was Dolby Atmos; this year it's DTS:X. While neither are terribly compelling yet due to a lack of software, if you're interested in better movie immersion, they're worth investigating.

The Onkyo TX-NR646 not only offers both formats but also some other useful inclusions, such as improved streaming features and greater connectivity. Onkyo has made some excellent-sounding home cinema receivers in its time, and that tradition continues with the TX-NR646. The receiver can also put forth decent music output too, and nice-to-haves like a turntable input sweeten the deal.

While it's not the best-looking receiver on the market and its user interface is ripped straight from a 1980s RadioShack catalog, it's got enough on the inside to compare well against a strong competitor like the Sony STR-DN1060 . If you don't care about proprietary multiroom audio in your AV receiver and instead want an exciting-sounding AV hub for your system, this Onkyo is a great choice.


Sarah Tew/CNET

Looks and usability are definitely the Onkyo's weak point, but neither is a deal-breaker. That's because AV receivers mostly sit quietly at the bottom of AV racks, requiring little little interaction beyond powering up, switching inputs and adjusting volume. If you want more from your receiver, look elsewhere.

The TX-NR646 has the looks and size of a British bulldog. It measures a standard 17-and-change inches wide, but stands almost 7 inches tall and over a foot deep. The front is generic-looking at best, all bathed in its green LED color scheme. One thing I've always appreciated about the design is the direct input buttons. No more random wheel-of-fortune spinning of a dial -- just press the input you want. That's about the only good point.

Sarah Tew/CNET

If we had a "worst remote control" award, then a receiver would no doubt scoop the pool, and it could easily be an Onkyo. The confusing clicker is bristling with more buttons than the bridge of a nuclear submarine, and the most-used buttons like Menu and Volume +/- are much smaller than those on competing devices. It's simply a poor usability experience in every way.

Sarah Tew/CNET

The menu system is likewise unchanged and ancient in feel, consisting of of white text on a black background. Onkyo is one of the last companies to offer a bare-bones menu in a midlevel receiver. Next year, guys?


While not a completely different beast than last year's model, the TX-NR646 does offer some significant tweaks. The most obvious is the addition of DTS:X, the newest "object-based" surround-sound format. Object-based surround, which also includes the better-established Dolby Atmos format, means better control over the placement of effects for producers, and the addition of "height" speakers for consumers. While high-end receivers offer the full complement of four height channels, "entry-level" receivers like the NR646 have just two, and in this case those are the fronts.

The TX-NR646 is a 5.2.1 (the last figure being height) receiver that has had a modest bump in (stereo) power over last year: 100W versus 95W.

Sarah Tew/CNET

Connectivity has been improved with an extra HDMI port on the back, as well as an extra stereo analog port. This brings the total of HDMI connectors to eight inputs and two outputs, all with HDMI 2.0 capability and HDCP 2.2 support.

Sarah Tew/CNET

The receiver boasts Wi-Fi on board in addition to Ethernet, and now offers Airplay for playback from iOS devices and Mac computers. There's also Spotify Connect, Pandora, SiriusXM Internet Radio, Slacker and TuneIn. Onkyo also has its own an iOS and Android apps that allow digital playback as well as general control.

Best AV Receivers for 2020

All best av receivers
  • Onkyo TX-NR585

    The Onkyo TX-NR585 combines newbie-friendly ease of use with the advanced decoding and...

  • Sony STR-DN1080

    Starting at: $598.00

    The Sony STR-DN1080 is fully featured, easy to use, and it sounds great, making it one...

  • Denon AVR-S750H

    Starting at: $499.00

    The Denon AVR-S750H offers everything an AV enthusiast needs, from generous sound quality...

  • Yamaha RX-V485

    Starting at: $399.95

    The Yamaha RX-V485 offers high-quality sound at an affordable price, but some users may...

More Best Products

All best products