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.]

The Hookup
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 . . .

Performance
You'll forgive me for rushing through the video evaluation of the TX-NR636, but since AccuEQ is a new and very interesting thing for me, I'm itching to discuss it. It's sufficient to say that I have absolutely no issues with the video performance of the receiver. Connected to a 1080p display for the bulk of my testing, I found that it passed all of the relevant tests on Spears & Munsil's High Definition Benchmark Blu-ray, as well as the HQV Benchmark DVD and Blu-ray discs, flawlessly. The HDMI and lip-syncing issues that I've had with Onkyo and Integra products in the past few years are also completely gone; I didn't have to adjust the sync controls one bit.

Now, let's talk about what AccuEQ does and does not do. Firstly, as I said above, it does not EQ the front left and right channels; equalization is only applied to the center, surrounds, and (if you use them) the backs or front heights. I also quickly discovered that it does nothing to the subwoofer, which is a shame since the frequencies between 20 and 200-300 Hz are the ones that benefit from digital signal processing the most.

I wish I were equipped to do the sort of measurements that Brent Butterworth does, so perhaps I could graph the before-and-after results. But since I can't, let's try to roughly quantify the effects that AccuEQ has on the remaining speakers as best I could hear. Imagine a scale from one to 10, with five being tonally neutral, 10 being extremely bright, and one being extremely bass-heavy. Assume that my front left and right channels are a five. Without AccuEQ engaged, my center channel is maybe a 5.5 (ever-so-slightly brighter), and my wall-mounted surrounds are about a 3.5 (quite noticeably richer in the bass department owing to boundary reinforcement). After my first pass at running AccuEQ, it did a pretty good job of evening out the bass boost in my GoldenEar surrounds, bringing them up to maybe a 4.75. In adjusting the center channel, though, it overshot the mark and brought it down to maybe a 4.5. I ran the test several more times with the microphone in several different positions, and sometimes it did a better job with the surrounds, while sometimes it didn't quite do as well. I couldn't find a measurement position from which it didn't overly dull the center, even if it was ever-so-slightly.

That was especially noticeable with the channel ID tests on the AIX All Star Band's Goldberg Variations Acoustica Blu-ray (AIX Records). It was a little less obvious when I popped in my recent favorite torture test for dialogue clarity, Cloud Atlas on Blu-ray (Warner). With AccuEQ on, voices and environmental effects locked to the center channel didn't quite have the same high-end sparkle and penetration, but it was a subtle difference. Ultimately, I decided after quite a bit of A/B-ing that I personally preferred the sound with AccuEQ off, since my brain could compensate for the slightly natural boost in brightness better than it could the slightly processed darkness. But what that A/B-ing also made pretty obvious is that AccuEQ isn't messing around in the time domain. So you never get that egregious deadening of the sound that can come from Audyssey MultEQ.

What was also obvious is that, with AccuEQ on or off, dialogue clarity was impeccable through the GoldenEar SuperSat 3 center speaker. Zachry's muttered gibberish in the opening sequence came through without a bit of struggle or strain. It was merely a choice, in my case, whether I wanted the harmonic overtones and high-frequency ambient effects to be a little over-pronounced (AccuEQ off) or a weensy bit too damped (AccuEQ on). If your center channel is a significant timbre mismatch for your fronts, you'll probably prefer it on. If it's a perfect match, you might prefer it off. Either way, though, I think AccuEQ is preferable to vanilla Audyssey MultEQ in most (although not all) ways, given that it does less harm to the mid and upper frequencies and imaging.

Let's move on from the AccuEQ discussion, though, because that's only one part of the equation when it comes to the TX-NR636. Skipping forward a bit in Cloud Atlas to chapter eight, I found the receiver's amps to be more than a match for the incredibly dynamic time-warping action sequences. I cranked the volume knob well past the reference point in my 13- by 15-foot room, and my ears gave out long before the Onkyo did. I usually write off buzzwords like Onkyo's WRAT (Wide Range Amplifier Technology) and H.C.P.S (High Current Power Supply) as mere marketing gimmicks, but in the case of the TX-NR636 I can confirm that there's something pretty special going on in the amp stage for a receiver at this price point, despite the occasional problem I had with its fault protection mode.

That same something special also came through wonderfully with Chicago's eponymous second album (aka Chicago II) on DVD-Audio (Rhino), especially with the "Ballet for a Girl in Buchannon" suite and "Memories of Love." The former really spotlights the TX-NR636's ability to crank out those majestic horn riffs, even when they're galloping out of all main channels, and the latter highlights its capacity for sweetness and robust swings in volume. If anything, these cuts really make me wish that Onkyo had the courage to rate its amps with all channels driven, because never once did the receiver struggle, even when called upon to belt out some truly punchy peaks from every direction at once.

Here's what really shocked me, though: the TX-NR636 also does an incredibly admirable job in straight-up stereo (okay, to be fair, 2.1) mode. As good as the trusty Anthem MRX 710 that normally resides in this room? Well, no. Pretty darn- tootin' close considering the price gap? You bet. I popped in Tool's Undertow (Zoo Entertainment) just to give the receiver another shot at rocking, and I was shocked at how well it delivered the big wall of sound of the second track, "Prison Sex." The ultra-wide soundstage of those creepy scraped strings in the intro stretched across the room from wall to wall, and once the track kicked in for realsies around the 20-second mark, the rich, thumping groove really drew me in -- in a way that a lot of low- to mid-priced AVRs simply don't. From there on out, the track isn't what you'd call overly dynamic, but the Onkyo/GoldenEar combo still delivered it with every ounce of punch that the track has to give, and the distant, echoing effect applied to lead singer Maynard James Keenan's voice just before the two-minute mark was beautifully resolved.

The Downside
As I alluded to before, my only substantial beef with the Onkyo TX-NR636 is that its new room correction system ignores frequencies that most need correcting. I hope that, as Onkyo continues to revise and refine AccuEQ, it adds some subwoofer correction to the mix. Unless you have some pretty sophisticated acoustical treatments in your listening space, chances are good that your room would benefit from some digital signal processing to tame room nodes in the frequencies between 20 and 200-300 Hz.

Of course, in dropping Audyssey MultEQ, Onkyo has also lost Dynamic EQ and Dynamic Volume, which I know a lot of you out there really dig. Mind you, I don't think this is any reason to overlook the TX-NR636. If you're shopping for a completely new home theater, though, and the Onkyo is on your short list of receivers, I would seriously consider adding a subwoofer with its own room correction system, like Paradigm's PBK (Perfect Bass Kit) or Sunfire's Room EQ.

Comparison and Competition
The mid-priced AVR market is a pretty crowded one, but Onkyo's TX-NR636 is the first of the new batch of HDMI 2.0-equipped receivers I've had the opportunity to test, so I can't make any direct comparisons in terms of performance.

Gauging by features alone, Pioneer's $700 VSX-80 7.2-channel networked AV receiver with HDMI 2.0 is rated at five watts less per channel, but it does feature a four-band Subwoofer EQ. I don't think Pioneer's HDMI 2.0 models support HDCP 2.2 copy protection, though.

Sony's $599 STR-DN1050 7.2-channel hi-res WiFi network AV receiver also boasts HDMI 2.0 connectivity and, as far as I know, lacks HDCP 2.2 compatibility. Sony claims that it delivers 165 watts per channel, but that's with one channel driven at one kHz into a six-ohm load. Two channels driven, measured from 20 Hz to 20 kHz, it's more like 100 watts per channel, but that's also with a six-ohm load. So it's actually probably not as powerful as the Onkyo. It does add AirPlay connectivity, though, which the Onkyo lacks.

Yamaha's $850 RX-V777BT should also be available this month, with built-in WiFi, Bluetooth, and roughly the same power output as the Onkyo TX-NR636. But I cannot for the life of me figure out if Yamaha's new models support HDCP 2.2.

For more comparisons, please visit Home Theater Review's AV Receiver page.

Conclusion
So, thumbs up or thumbs down on the TX-NR636 7.2-channel network AV receiver? I say thumbs up. Way up. If the company had only included subwoofer correction in its new, proprietary AccuEQ system, I would climb a stepstool to get my thumbs a little higher. It isn't the perfect AV receiver, but it punches above its weight in terms of clear, dynamic, spacious sound, and the future-proof-ish connectivity doesn't hurt a bit. The networking features are nice and easy to use, if you're into that sort of thing. If not for the issues I had with the fault protection mode, setup would have been incredibly straightforward and painless.

More importantly than that, I'm happy to see Onkyo making substantial improvements to its new line in ways that don't stand out on a bullet-point ad sheet. I didn't have a single handshake issue with the HDMI connections, nor did I have to make any lip-sync adjustments, as I have with Onkyo (and Integra) products in the past. So, if you're making the upgrade to UHD or plan to in the near future, if you only have $700 to spend on a receiver, and if you have an affinity for Onkyo receivers, the TX-NR636 surely isn't a bad buy at all. It's an improvement over last year's equivalent model in almost every way. If by some miracle, a legitimate, open-platform, mass-market, high-frame-rate 4K source component comes out this year, this may be one of the very few receivers capable of switching it until next summer.