Setup: Quick, but manual is better
The STR-DN840 uses Sony's Digital Cinema Auto Calibration (DCAC) automatic speaker calibration system. The owner's manual recommends turning your subwoofer's volume control to the midpoint, and if the sub has a crossover control knob, setting it to the highest number setting -- a good start. The onscreen display guides you through choosing the correct "SP Pattern" (speaker pattern) for you home theater, which in plain English means how many speakers are in your home theater, and if you're bi-amping the front speakers, or using height speakers, etc. Next, you plug in the supplied calibration microphone and the fully automatic process takes about a minute to complete.
The STR-DN840 determined that all of the speakers in our Aperion Intimus 4T system were "large," and that's certainly not the case. The tower and center speakers just have two 4-inch woofers, and the little 8.75-inch-tall surround speakers have a single 4-inch woofer. We ran the DCAC a second time and it again identified all of the speakers as large.
We listened to the STR-DN840 with those settings and the sound was fine, but when we went into the manual setup and changed all the speakers to small, with the 4T towers set to a 80Hz crossover, and the center and surround speakers with 100Hz crossovers, the sound improved. Even so, we noted that our Hsu Research VTF-1 MK4 subwoofer wasn't loud enough. We turned the sub's volume up to improve the blend with the Aperion speakers.
It's the same story we usually have with automatic speaker calibration: it generally doesn't bring out the best possible sound from a home theater speaker setup. It's worth at least giving the manual speaker setup a try to see if you can do better. If you're not sure you improved the sound, you can always rerun the automatic calibration.
Sound quality: Up to the task
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.
After we manually re-setup the STR-DN840 and listened to a few movies and some music, the sound was improved. Peter Gabriel's excellent "New Blood: Live in London" Blu-ray transported us to the concert. The enveloping soundfield from the front and surround speakers was spacious, and Gabriel's vocals sounded extremely live and present. The orchestra's sound was clear and highly detailed, and the concert hall's ambience sounded natural.
The scene in the "Jurassic Park" Blu-ray where a T-Rex chases a galloping herd of smaller Gallimimus dinosaurs demonstrated the STR-DN840 home theater skills. When the T-Rex captures a Gallimimus and tears it to shreds, the sound was quite good, but switching over to the Marantz NR1403 receiver, the two animals' ferocious struggle was more viscerally presented. That receiver, which is "only" rated at 50 watts per channel, sounded more powerful than the STR-DN840. There was nothing "wrong" with the STR-DN840's sound, but the NR1403 sounded more fleshed out and realistic.
CDs, played over just the two Aperion 4T tower speakers, consistently produced perfectly enjoyable sound. With the best-sounding discs, like Jonny Greenwood's orchestral score to the movie "The Master," produced a huge, wall-to-wall sound stage from the two speakers.
What are the alternatives?
The STR-DN840 is clearly the best option in its price class for value, so the best alternatives take a different tack.
Sony's step-up STR-DN1040 ($600) is worth a look. It packs a whopping eight HDMI inputs and also includes an excellent graphical user interface that tops anything we've seen at its price. We still think the STR-DN840 is the better pick for most buyers (do you really need eight HDMI inputs?), but the STR-DN1040 certainly makes you feel like you're getting your money's worth.
On the other end of the spectrum, we still like Marantz's slimline NR1403 ($400). It lacks all the great wireless features on the STR-DN840, but you can always add some of that functionality later with, say, an Apple TV. The real attraction is the NR1403's handsome, compact form factor that tops just about anything else available.
Finally, it's worth considering whether you even need a 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.