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.
Setup: Not quite on the mark
The TX-NR525 features Audyssey's MultEQ automatic speaker calibration system, which takes just a couple minutes if you use the Quick Start option. Audyssey correctly identified all of our speakers as "Small" speakers and came up with a 100Hz crossover setting for all five speakers. That crossover setting is fine for the Aperion's center-channel speaker and the satellites used for the surround channels, but 100Hz is too high for the Aperion 4T tower speakers we test with, which we usually run with a 60Hz setting.
When we checked why Audyssey selected that crossover setting we discovered the TX-NR525 is limited to only one crossover setting for all the speakers in the system. That would be fine if you're using similarly sized speakers for the front left, right, center, and surround channels, but since our front left and right speakers are towers and the others are much smaller, the 100Hz setting was a compromise. Audyssey also set the subwoofer volume much too high, which we also encountered with the.
We next tried the full MultEQ routine, moving the mic to six different positions in the CNET listening room, and that took about 12 minutes to complete. MultEQ came up with the same 100Hz crossover setting, and the sub was again definitely too loud. The sound was a little different than it was with the Quick Setup, because after you run MultEQ, you get the Audyssey Movie EQ setting, and Audyssey Dynamic EQ is turned on. That's a shame; those features are useful for maintaining volume and tonal balance for late-night listening levels, but they add unwanted processing and limit dynamic range for normal listening. If you're paying $400 for an AV receiver, you deserve to hear it at its best. We ended up manually turning down the subwoofer volume for our listening tests.
Sound quality: Just below par
Sound-quality evaluations of AV receivers (and other amplifiers) are controversial. Some say all AV receivers sound the same, others disagree, and we're not likely to settle that argument anytime soon.
What we can say is that AV receiver sound quality has much, much less effect on overall sound quality than speakers or room acoustics, so you're better off spending your home theater budget there. CNET's sound quality evaluations are strictly subjective, with resident golden ear Steve Guttenberg comparing similarly priced models in an identical listening environment using the same speakers.
We started our listening tests with our usual action movies and music discs, and we noticed right away that the subwoofer and towers' blend was a bit off. Ideally, you don't want to hear the subwoofer as a distinct source; all the bass should appear to come from the speakers. That was the case, but the 4T towers didn't have the muscular bass power we get from other receivers, including the Onkyo TX-NR626 (we had the subwoofer volume turned down on both receivers from the Audyssey settings). The subwoofer's bass isn't the issue, it's how it blends with the speakers.
With some of the better music Blu-ray discs, like "Brand New Opry: Here & There" the acoustic instruments had a bit more body and weight to their sound with the TX-NR626, and vocals were more realistic too. The TX-NR525 was close, but not the same, though both receivers created excellent, room-filling surround.
With the "I Robot" Blu-ray we fast-forwarded to the scene where Del Spooner (Will Smith) gets assaulted by robots while driving his sports car. The robots are piloting two large trucks, and the barrage of shredding metal, screeching tires, breaking glass, and gunshots was impressive, though we felt the TX-NR626 communicated the hard-hitting dynamics with more authority than the TX-NR525.
Finishing up with music, we put on the "Cream: Royal Albert Hall, 2005" Blu-ray, and were to find the Sony STR-DN1040 receiver produced a more immersive surround feel to the concert than we heard from the TX-NR525. Not only that, the front three speakers' sound stage depth was more fully developed, and Jack Bruce's electric bass had superior definition as well.
The TX-NR525 sounded perfectly fine on its own, but the other receivers edged it out on a number of counts.
What are the alternatives?
The strongest alternative to the TX-NR525 is Sony's STR-DN840. Yes, it's more expensive, but you're getting a lot of added wireless functionality for $50. If you're considering getting one of Onkyo's wireless accessories, the price difference is nearly moot and you end up getting more without needing to have a USB adapter hanging out of the front of your receiver.
From the other end of the spectrum, Marantz's NR1403 is a tempting no-frills option if you're mostly interested in the TX-NR525's six HDMI inputs and the superior sound quality an AV receiver offers compared with sound bars. The slimline look is considerably sleeker than the bulky TX-NR525's appearance, although note that the NR1403 doesn't offer any networking functionality. (And that's .)
Finally, it's worth considering whether you even need an full-fledged AV receiver in the first place. If you're willing to downsize your home audio system to stereo, you might be able to use a. They sound great, take up a lot less room, and can make your home theater much simpler.
Conclusion: Packed with HDMI, but weak on wireless
The Onkyo TX-NR525 offers up a lot of HDMI connectivity for the price, but it's not the best value pick if you want wireless audio streaming, even with its affordable adapters.