It's generally a pretty safe bet that, if you want or need a receiver with the latest and greatest in AV connectivity, you're more likely to find it closer to the upper end of a company's product range than at the entry level. At least at first. But oddly, with the introduction of HDMI 2.0 (the new spec that allows for 60-frame-per-second Ultra HD, ultra-wide 21:9 video, and much higher audio sample rates and channel counts...without the need for new cables, thank goodness), Onkyo has taken exactly the opposite approach. The company introduced the new port first in its budget-oriented AVRs, the $499 TX-NR535 and the $699 TX-NR636, with two higher-end models following shortly thereafter. As such, the two receivers have garnered no small amount of anticipatory talk amongst AV enthusiasts on the verge of their next receiver upgrade, with the 7.2-channel TX-NR636 hogging the bulk of the discussion.
If HDMI 2.0 were the only new feature of the TX-NR636, I still think it would make for an interesting receiver and worthy of all the talk. But, of course, it isn't. In addition to the new connectivity standard, the TX-NR636 also supports the next-generation HDCP 2.2 copy-protection scheme, which gives it a bit of future-proofing. But only a bit, since HDCP 2.2 is only supported on one HDMI input port. (If you're curious, it's the one labeled "STB/DVR," which may give some indication as to which source components Onkyo predicts will likely embrace the more advanced copy-protection system first.)
And yet, for this old audio junky who still hasn't made the permanent upgrade to Ultra HD and probably won't anytime soon, that still isn't the most intriguing thing about the TX-NR636. What fascinates me far more is that Onkyo has abandoned its relationship with Audyssey entirely in favor of its own proprietary room EQ solution, dubbed AccuEQ. This is a contentious decision, to be sure, since Audyssey has its fair share of fans. It really isn't all that surprising, though. Onkyo has always seemed to have a somewhat weird relationship with Audyssey, from my point of view. Last year's models sported basic MultEQ all the way up to the TX-NR828, with the TX-NR929 making the full leap to MultEQ XT32, ignoring the step-up MultEQ XT along the way. For a more in-depth explanation of the differences between Audyssey MultEQ, MultEQ XT, and MultEQ XT32, check out our article "Automated Room Correction Explained."
We'll dig deeper into the differences between Audyssey and AccuEQ in the Hookup and Performance sections of the review, but it's worth noting here that Onkyo is very upfront about the fact that AccuEQ doesn't apply any form of equalization to the front left and right channels, a decision made (according to the company) in order to allow you to "enjoy balanced surround sound regardless of room shape or furnishing while retaining the characteristics of your front left and right speakers for optimum enjoyment."
Other features and specifications include 95 watts of power per channel into an eight-ohm load (measured with two channels driven, 20 Hz to 20 kHz, with 0.08 percent total harmonic distortion) and 115 watts per channel into a six-ohm load (measured with two channels driven at one kHz, with 0.7 percent total harmonic distortion). Unlike its European, Australian, and Asian counterparts, the TX- NR636 available in North America does not feature adjustable speaker impedance settings, although curiously Onkyo does provide dynamic power ratings for eight-, four-, and even three-ohm loads on its product page. Personally, I wouldn't attempt to drive a four-ohm speaker with the TX-NR636, although that fact is unlikely to affect your speaker selection if you stick to the mainstream. If you'd like to learn more, you can check out our primer on "How to Pick the Right Amp for Your Speakers (or Vice Versa)."
As its name implies, the TX-NR636 7.2-channel network AV receiver is also packed with IP-connectivity features, including Pandora, Sirius/XM, Slacker, Aupeo!, TuneIn, and Spotify, with Spotify Connect scheduled to be added in a future update. It also features built-in Bluetooth and WiFi (although no AirPlay) and supports playback of high-resolution files via DLNA or USB. The TX-NR636 also features both Network Standby and Wakeup via Bluetooth options within its setup menus, allowing you to easily fire up the receiver via the IP connection or your smartphone.
[Editor's note, 8/12/14: Onkyo has informed us that the TX-NR636 will receive a firmware update some time in September to make it Dolby Atmos ready, so that's another feature to add to the list. For more info on Dolby Atmos, check out this story.]
Only four of the TX-NR636's six rear-panel HDMI inputs are capable of accepting a 4K signal, and as I said above, only one of the inputs (HDMI 3 STB/DVR) and one of the outputs (HDMI Out Main) supports HDCP 2.2. I briefly had the opportunity to connect the TX-NR636 to Samsung's new UN65HU8550 UHD display to test the receiver's HDMI 2.0 capabilities, and I can confirm a solid handshake even using my old high-speed HDMI cables. Of course, I couldn't test HDCP 2 compliance (no available sources), but I did get to spend a few minutes testing the receiver's UHD pass-through and upscaling capabilities, both of which were spot- on.
After that I moved the receiver into my secondary home theater, which is pretty lean in terms of sources at the moment, housing only my Dish Network Joey DVR client and an older OPPO BDP-93 Blu-ray player. Since both connect via HDMI, source setup was a snap. Although I didn't have to rename any inputs, I tinkered around with that function and found it incredibly straightforward and intuitive. The main HDMI output also supports Audio Return Channel functionality, but only if you turn on HDMI CEC.
The speaker connections are a little more straightforward, although somewhat crowded. I didn't find that to be a significant issue given that I use banana plugs; but, if you're opting for a straight-wire connection or spade plugs, you might find the working conditions to be a bit cramped. I connected the TX-NR636 to a GoldenEar SuperCinema 3 speaker system consisting of five SuperSat 3 speakers and a ForceField 3 subwoofer. To the left of the traditional front left/right, center, and surround left/right speaker connections, the receiver also has binding posts for either a pair of surround back or a pair of front height channels (which can alternately be used to bi-amp the front left and right speakers), as well as a powered Zone 2 output. You can only amplify seven channels at a time, though. If you opt for bi-amping, the powered Zone 2 option is disabled entirely in the setup menu; and, if you opt for a 7.1 system, those extra channels are temporarily disabled when you activate Zone 2, leaving you with stereo in the second zone and 5.1 in the main zone.
As is usually the case with Onkyo's mid-line receivers, the power cord is not detachable. As is always the case with Onkyo's receivers at any price point, I found the setup menus to be an absolute pleasure to navigate. The company won't win any beauty awards for its GUI, but everything is easy to find and simple to explore, the only caveat being that you don't press the button labeled "Setup" on the remote to actually enter the setup menu; instead, it's accessible via the Home button.
Speaker setup has been simplified quite a bit from the old Audyssey days, but the microphone looks identical to last year's models. Simply plug it into the front port on the TX-NR636, and the calibration process begins. AccuEQ begins with a subwoofer test tone and a screen that reads, "Make sure the output from subwoofer [sic]. If sounds cannot be detected, check if the subwoofer is turned on or adjust volume settings." Then, after a quick channel test, it plays a few seconds of slightly warbly pink noise from each speaker, measures from one position only, quickly calculates the results, and that's that.
Much to my surprise, AccuEQ positively nailed all of the setup parameters for my room. Crossover frequencies, levels, and distances to the five main speakers were dead-on balls accurate, as we say here in Alabama. If you take the distance readings at face value, it did place my subwoofer in another room altogether, but that's entirely normal when you understand that distance settings really aren't about physical distance; they're about delay, and a subwoofer's signal is generally going to be more delayed than the rest of your speakers. So this is entirely normal. In that respect, AccuEQ gets an A+.
The only notable issues I faced during the setup process related to the receiver's fault protection mode, although one of the issues should probably be attributed to the peculiarities of my own system. I initially attached the Ethernet connection of the TX-NR636 to an eight-port network switch with PoE capabilities, which caused frequent, although inconsistent, shutdowns, eventually requiring a factory reset to the receiver. Once I replaced that switch with a non-PoE enterprise-grade
Cisco solution from Access Networks, that problem resolved itself. (I only found out after the fact that Onkyo expressly recommends not using a PoE switch.)
The fault protection issue did rear its head again at the end of my evaluation period, though, for a completely different reason. I received RBH's new CTx Series 5.1 speaker system for review, and despite the fact that the speakers' nominal impedance is listed as eight ohms for the main satellites and six ohms for the center channel, the TX-NR636 went into fault protection mode again and again when called upon to deliver any appreciable dynamic peaks at pretty reasonable listening levels in my rather small secondary listening room. I had no such problems when using my GoldenEar SuperCinema 3 speaker system, though.
Click on over to Page Two for the Performance, Downside, Comparison and Competition, and Conclusion . . .