If I were in charge of Onkyo product development, there's almost certainly no way a product like the TX-RZ900 7.2-channel, THX-certified AV receiver would exist. So it's a very good thing that I'm not in charge of Onkyo product development, because I'm glad that it does.

Before you Onkyo fans get your knickers in a bunch, allow me to explain. For a while now, I've rather felt like Onkyo and sister brand Integra have struggled to differentiate themselves. The former is, conventional wisdom holds, the consumer-facing, big-box-store-and-online-retailer wing of the duo, with the latter being aimed more at the custom installation market. Those lines have been getting blurrier and blurrier for years, but the $1,599 TX-RZ900 positively wipes them out.

That's not to mention the fact that the new RZ Series represents (to my mind) a significant step up in terms of performance and quality from a company that already drew hefty accolades for last year's models. The RZ900, for example, boasts a hand-wound, high-current toroidal transformer, extra-large capacitors and hotrod transistors, plus a beastly Asahi Kasei AK4458 384/24 DAC (with DSD capabilities), combined with Onkyo's own Vector Linear Shaping Circuitry for improved digital-to-analog conversion. It also features the bleeding edge in terms of video connectivity, with eight HDR-capable HDMI 2.0a inputs (and two outputs), five of which are HDCP 2.2 compliant, in addition to a pair of component and three composite video inputs for any legacy devices you may still have kicking around.

Pile on top of that a great collection of streaming apps (Pandora, Spotify, Sirius, Slacker, TuneIn, and Deezer); built-in WiFi, AirPlay, and Bluetooth; and support for both Dolby Atmos and DTS:X (the latter via firmware update), and you've got the makings of one heck of a beastly AV receiver.

Getting back to those blurred lines between Onkyo and Integra's territory, though, the TX-RZ900 also manages to be both an integrator's and an enthusiastic DIY tinkerer's dream, thanks to its wealth of control connectivity--including RS-232, IP, back-panel IR, ONKYO-RI System Control, and Remote Interactive Over HDMI. It also comes with an incredibly intuitive setup wizard to walk you through the process of setting up its included controller as a universal remote.

So yeah, in a marketplace trending toward increasing simplicity, in the age of the soundbar when most consumers don't even really understand what a receiver is, and with its sister company already dedicated to higher-performance, custom-integrated audio gear, Onkyo has dropped a big beastly black box aimed at professionals, hardcore tinkerers, and audiophiles alike. And kudos to them for doing so.

The Hookup
When I say "big beastly black box," by the way, I'm not even slightly kidding. The TX-RZ900 measures in at nearly 8 inches tall and over 17 inches deep, and it weighs just shy of 40 pounds (which, for perspective, puts it somewhere in between the weight of Samsung's latest 48-inch SUHD TVs with and without their stands installed).

Size and heft weren't really the first thing I noticed about the receiver as I pulled it out of its crate, though. What stood out at first glance were its feet, which are beautifully sculpted and feature a ring of cork on bottom to provide isolation from vibration. I don't have a foot fetish, mind you, but that's a seriously nice touch.

And really, "nice touch" is a recurring theme with the build quality of the RZ900. In terms of fit and finish, it's a deft combination of polished and bulletproof. If I have one complaint about aesthetics and ergonomics, it's that the great big volume knob feels far lighter and less substantial than it looks, but that's a minor complaint. In terms of actual use, it allows for a level of precise volume adjustment the likes of which I haven't seen in some time.

Around back, the RZ900 has every right to be an utter mess in terms of layout, given its wealth of connectivity, but nothing could be further from the truth. The binding posts--gorgeous, expensive-feeling things--are beautifully laid out, with the main five-channel array arranged horizontally along the bottom and the additional speaker connections (rear surround/height/bi-amp/powered zone 2) stacked off to the side. I relied on banana-terminated speaker wires to connect my Aperion Audio Intimus 5B Harmony SD speaker system to the receiver, but I also ran bare speaker wires when I (briefly) tested out an Atmos setup with a couple of temporarily ceiling-mounted GoldenEar SuperSat 3s, and I was impressed by just how easy a straight connection was.

Speaking of easy, the RZ900's setup menus remain among the most intuitive in the industry, in my opinion, which is good, because there's a lot of setting up to be done. The wizard that awaits you after firing up the receiver for the first time is straightforward and simple without pandering. It's easily accessible to intermediate do-it-yourselfers without being insulting to more experienced installers. There are still some hilarious translation faux pas to be found (my favorite being the ever-popular "Make sure the output from the subwoofer"). But the wizard does a great job of illustrating your various setup options and speaker configurations.

It's worth noting here that the wizard does allow you to configure a 7.1.2 speaker setup (that is to say, seven speakers at ear level, one sub, and two overhead speakers), and it does have enough binding posts to accommodate the hookup of such. Given that it only features seven amplified channels, though, you're forced to choose whether you want to hear 7.1 or 5.1.2 when it comes time to listen. We've confirmed with Onkyo that, even if you tap into the pre-amp outs and add an external amp, it's not possible for the RZ900 to process nine channels of audio simultaneously.

Once your speakers are configured, the wizard allows you the option of running its updated, second-generation AccuEQ room correction. Don't let the similarity in the setup screens (or the same hilarious typos mentioned above) fool you. This year's AccuEQ is a wholly different beast from the first version.

For one thing, while last year's TX-NR636 hit the ball out of the park in terms of automatically detecting crossover frequencies, levels, and distances for my speakers when running AccuEQ, the RZ900 completely dropped said ball in terms of crossover points. It wanted to set the crossover for my fronts at 120Hz (way too high) and my surrounds at 40Hz (oh so very hilariously low). And although it looks like you ought to be able to adjust such settings from the wizard itself, all you can do is click the button and agree to accept the automatic results. Thankfully the RZ900's configuration menus are so intuitive that changing these settings manually was a cinch, and I did not need to make any changes to the delay settings or levels.

The first substantial clue that we're dealing with a wholly different AcceEQ comes from the last step of the automatic setup, where you choose whether to apply room correction to all speakers or leave the front left and right speakers untouched. With the previous version of AccuEQ, correction was never applied to the front mains, nor to the subwoofer. Thankfully, though, Onkyo listened to feedback, and as such, the bulk of the new AccuEQ's processing is applied to the sub and to the very lowest reaches of the main channels, which is how it should be.

If you're interested in a deeper discussion of why this is the case, and for my thoughts on room correction in general, check out Automated Room Correction Explained.

With that out of the way, I dug through the menus a bit to change some settings that I think are set rather questionably by default. There's pretty much no way, for example, that anyone would actually want two-channel material to default to All Channel Stereo processing. But I absolutely adore how easy it is to adjust default modes for the variety of different inputs. All in all, the setup process was smooth and easy (considering just how much there is to tweak, that is), and the only setting I had to really dig for was the Network Standby function, which allows one to power the RZ900 on via IP. This is important if you want to use Onkyo's control app or, in my case, a simple Ethernet connection to operate the system via Control4 or another whole-home control system. The RZ900 does support Simple Device Discovery Protocol for Control4, by the way, so getting the receiver integrated into my home automation system took mere moments.

Click over to Page Two for Performance, The Downside, Comparson & Competition, and Conclusion...

Performance
I've been itching for months to check out the new AccuEQ system, so I didn't spend too much time evaluating the RZ900's video performance. Mostly because there isn't much to evaluate. It passes through 4K just fine, but it doesn't offer anything in the way of upscaling, so my Spears & Munsil disc didn't get much play.

The first disc I popped in to put AccuEQ 2015 through its paces was the Extended Edition of The Hobbit: The Battle of the Five Armies (Warner Home Video). I'd just watched it the evening before in my main home theater, so I knew exactly which scene to cue up first to get a sense of just how well this new room correction system handles critical bass correction, especially in terms of standing waves: Chapter 2, "Bard the Dragon-Slayer."

The lead-up to the show-down between Bard and the dragon Smaug provides oodles of opportunities for the RZ900 to flex its muscles, and so it did. The sound was rich, detailed, and utterly dynamic even at ear-blistering listening levels, with plenty of overhead thanks to the receiver's beefy amps, which are rated rather convolutedly at 140 watts per channel at eight ohms, 20 to 20 kHz, with two channels driven and 200 watts per channel into six ohms, measured at 1 kHz, with one channel driven, with peak dynamic output of 160 watts into eight ohms and 270 watts into four ohms. For more information on what these numbers mean, see How to Pick the Right Amp for Your Speakers (or Vice Versa).

The one thing that stands out the most in the early parts of this sequence is that--despite the flaming chaos, despite the big, bold, enveloping surround mix, despite the fact that every speaker front and back seems to be running for its life--dialogue intelligibility remains top-notch either with or without AccuEQ engaged. Until, that is, Smaug opens his gigantic mouth. It's here where Onkyo's new room correction system truly shines.

Without AccuEQ engaged, in my room at least, Smaug's voice is a booming, sloppy, bloated mess of bass that rattles the walls and smears the entire audio experience. A simple flip of a switch in the RZ900's Quick Setup menu engages AccuEQ and puts everything truly, utterly, completely in its place, sonically speaking. With AccuEQ on, Smaug's voice is still thunderous. It still smacks you right in the chest with deep, rich, impactful resonance. But it does so with control. With finesse. With impeccable clarity.

Here's the thing, though: in my room, that's just about all that AccuEQ does to the audio, and rightly so. Whereas last year's AccuEQ tended to darken vocals and the overall timbre of my sound system (the centers and surrounds, at least), AccuEQ 2015 leaves everything from the midrange on up effectively untouched. As it should. There's none of the deadening that comes with Audyssey. There's none of the messing around with the soundstage that comes with other room correction systems on other mass-produced receivers. Although it might not be as refined, and although it doesn't offering nearly the number of setup parameters (much less the number of measuring positions), I'd put the new AccuEQ in the same category as superior room correction systems like Anthem Room Correction and Dirac, at least in terms of the effect it has on standing waves. It may not deliver results as perfect as those aforementioned systems, but it gets you 80 percent of the way there with a fifth of the effort.

And unlike last year, when I found myself preferring AccuEQ on for (some) movies and off for music, I found that Onkyo's new room correction system is best left on for any source and any type of listening material.

Abigail Washburn's "Bring Me My Queen" from her City of Refuge CD (Rounder Records) is a fantastic example of why. Quite frankly, I find this song unlistenable on a receiver with Audyssey or similar room corrections, especially starting at around the 1:30 mark. The balance of delicate vocals, light percussion, banjo, piano, and bass gets thrown away out of whack, and the soundstage is just all wrong. But without any form of room correction, the bass can get janky and overwhelming.

With AccuEQ, though (this new version, anyway), the balance is completely perfect. The bass supports the song but doesn't dominate it, giving it weight without weighing it down. Even in stereo mode, the RZ900 delivers the tune with all of its stunning width (and its subtle hint of soundstage depth) intact, and pushes the intertwining fiddles in the song's bridge (starting at about the two-minute mark) out into the air with a natural grace that does the song justice.

The Downside
In terms of performance, I have few if any complaints about the TX-RZ900. For a receiver in this price range, it delivers the goods and delivers them well...which isn't to say that everything about the receiver is perfect. As much as I raved about the receiver's menus in terms of navigation, I think they could stand to be a little more informative, given the wealth of options and the sheer number of sound modes packed into this big, black box. Like, what, exactly, is the difference between Pure Audio and Direct? I found myself turning to the phone book of an instruction manual every time this question entered my brain, and I think a bit of explanation in the UI would help alleviate such confusion.

Other than that, my only constructive criticism would be that Onkyo needs to work on AccuEQ a little more to perfect its detection of proper crossover settings. Perhaps it could default to 80 Hz and run a quick check to see if the speakers can handle such a crossover setting, then go from there

Other than that, as I said, no significant complaints.

Comparison and Competition
Here we come back to the point I was hinting around about in the intro: the TX-RZ900 does have some pretty stiff competition, mostly in the form of Integra's DTR-50.7 7.2-channel network AV receiver. There are some slight differences in the amplification ratings, and the DTR-50.7 does have a little more in terms of control connectivity (in the IR and 12v trigger department), as well as HTBaseT, but the Onkyo does have much nicer binding posts, as well as built-in Bluetooth and WiFi. Plus it costs a bit less, and you can buy it pretty much anywhere. But otherwise, the two are startlingly similar and hard to pick between unless you're going whole-hog with multi-room distributed AV.

There's also the Pioneer Elite SC-97 9.2-channel network Class D3 AV receiver to consider. Like the TX-RZ900, it supports Dolby Atmos and DTS:X, and it boasts many of the same goodies that make the Onkyo such a standout, including IP control, the latest HDMI connectivity with HDCP 2.2 support, and built-in WiFi and Bluetooth. However, it adds a few bonuses like video scaling. The SC-97 also comes with Pioneer's own MCACC Pro room correction system, which I'll admit I have very little experience with, so I can't make intelligent comparisons between it and Onkyo's excellent new AccuEQ.

The RZ900 also sort of splits the difference between Yamaha's RX-A2050 and RX-A1050 AVENTAGE network AV receivers, if you've been looking for a nice middle-ground between those. Conversely, if you want a little more than the RZ900 delivers or need to step down a weensy bit, these two offer a nice alternative. The former is a 9.2-channel receiver, whereas the latter is a 7.2-channel model with a little less power than the Onkyo delivers. Both support Dolby Atmos and DTS:X, though, and both rely on Yamaha's YPAO room correction (which I don't like as much as the new AccuEQ, although it does have its ardent fans).

Conclusion
When you get right down to it, the Onkyo TX-RZ900 AV receiver isn't right for everyone. If you're looking for a simple plug-and-play solution, this ain't it, even compared with other AV receivers on the market. Its connectivity is so plentiful as to be a little overwhelming, and I can imagine its setup being a little daunting for some users, despite the exceptional well-designed wizards. Quite frankly it's more receiver than the vast majority of people need.

But all of the above speaks directly to why I heart it so much. You could argue that Onkyo is competing with itself by offering a receiver outside of the Integra lineup that's so very Integra to its core, but that's not my problem to worry about. Evaluating the TX-RZ900 on its own terms, it's an exceptionally high-performance offering that proves just how much Onkyo has been listening to its fans and critics alike over the past few years. I didn't have a single issue with it during my evaluation, neither with HDMI switching nor fault protection. And the sound it delivers is simply fantastic. Wrap all of this up in a gorgeous chassis with (in my humble opinion) very sexy styling, and there's no denying that Onkyo has a winner on its hands here.

Additional Resources
• Check out our AV Receiver category page to read similar reviews.
• Onkyo Announces RZ Series of AV Receivers at HomeTheaterReview.com.
• Iron Maiden Hi-Res Catalog Exclusively on OnkyoMusic at HomeTheaterReview.com.