Onkyo has resisted adding support for Apple's AirPlay standard to its AV receivers, but historically the company has made up for that shortcoming by offering more HDMI inputs for significantly less than the other guys. The Onkyo TX-NR525 ($400 street) sticks to that script, offering more HDMI inputs (six) than other $400 networked AV receivers, plus niche features like dual subwoofer outputs and second-zone audio support. Onkyo is also the only manufacturer to offer reasonably priced accessories to add Bluetooth ($50) and Wi-Fi ($30) via small USB adapters.
But the TX-NR525 doesn't quite stand out as a exceptional value, like Onkyo's previous models have. That's largely due to the existence of Sony's STR-DN840 ($450), which includes built-in Wi-Fi, Bluetooth, and AirPlay for just $50 more -- money well spent, in our opinion, for integrated wireless audio streaming from nearly any tablet or smartphone. The TX-NR525 is still a solid all-around AV receiver, but it's not quite in our top tier of value picks, although keep an eye on the street price, as Onkyo receivers have a tendency to fall in price as the year goes on.
Design: The boxiest box
AV receivers are big and boxy by nature, and Onkyo's models may be the boxiest of them all. The TX-NR525's sharp edges and large, flat front panel give it a muscular, brutish look that doesn't exactly blend into a typical living room.
It also has a busier front panel than most, especially compared with the more modern-looking Sony STR-DN1040. It wouldn't be our first pick for aesthetics; if you want something that looks nicer, look at Marantz's NR1403 or a compact integrated amplifier.
The included remote is good, as far as AV receiver remotes go. The white buttons make it easier to select things in a dim home theater and important buttons like volume and the directional pad are well-located. It's not as simple as the Denon AVR-E400's clicker, but it's also miles better than the inscrutable remotes included with the Pioneer VSX-823-K and Yamaha RX-V475.
Features: Six HDMI inputs
The TX-NR525 offers more features than the typical $400 networked receiver.
That's largely due to the six HDMI inputs on the back panel. There's healthy support for legacy connections too, but those are much less important now that the majority of devices use HDMI.
Out of the box, the TX-NR525 requires a wired Ethernet connection to take advantage of its networking features, such as smartphone control, firmware updates, and access to Onkyo's suite of integrated streaming services, which include Pandora, Spotify, Rhapsody, SiriusXM, Slacker, and Internet radio.
If you don't have Ethernet in your living room, Onkyo offers the UWF-1 Wi-Fi adapter for $30 -- a very reasonable price compared with the adapters offered by Yamaha ($100) and Pioneer ($125). Onkyo also offers a $50 Bluetooth dongle, which will let you wirelessly stream audio from nearly any smartphone or tablet, although note that you can only use one USB adapter at a time, since they only work with the front USB port.
The rest of the features are less important for mainstream buyers. The TX-NR525 is "only" a 5.2-channel receiver, but most buyers won't need the extra functionality that a seven-channel receiver makes possible: surround back channels, powered second-zone audio, and Dolby Pro Logic IIz "height" channels. There's no analog video upconversion, but again, that's less of a concern now that most modern devices use HDMI. And while AirPlay isn't built in, you can always add that functionality later with an Apple TV, which is arguably a smarter move anyway.
If you're looking for more-detailed feature comparisons, check out our giant AV receiver spreadsheet, which compares the TX-NR525 with other 2013 models as we review them.