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Denon AVR-4520CI Review


  • Smooth, fatigue-free treble
  • Good bass clarity and definition
  • Well-thought out feature set
  • Outstanding video processor


Our Score 7
User Score 4


  • Audio performance outclassed by the competition
  • Sound lacks dynamics and punch
  • Recessed, flat, and lifeless-sounding midrange
  • The most irksome auto set up program we’ve used yet
Unless the Denon AVR-4520CI’s features are exactly what your system needs, we’d recommending looking elsewhere for a top-tier A/V receiver.

One need only look at Denon’s receiver lineage to realize this company takes its flagship models seriously. In fact, it could be argued Denon was the first to throw down the gauntlet in the receiver wars, when in the year 2000 it released its 62 lb., $3800 monster, the AVR-5800. Sporting a cutting edge design and enough wattage to power a small village, Denon’s AVR-5800 certainly wasn’t for the faint of heart.

Denon then outdid itself a few years later with the even more ginormous, 10-channel AVR-5805. With 1700 watts of total power, a 97-pound chassis, and a $6000 price tag, the AVR-5805 and its variants firmly situated Denon as the most ambitious receiver maker of them all. To this day, the AVR-5805 stands as the largest and heaviest A/V receiver extant.

Looks like times have changed since those behemoth receiver days. Denon no longer has a 5800-series model in its lineup at all. Instead, the $2499 AVR-4520CI takes pride of place as Denon’s latest top model. On the surface, it certainly looks like a worthy flagship given today’s more price-conscious marketplace: Its features list and specs certainly tick all the right boxes, at least on paper. Still, the proof is in the listening, so we decided to put the 4520CI through its paces to see if it delivers all the performance it promises.

Out of the Box

Even though we’ve seen a few pictures of the Denon on the interwebs, those pics didn’t do justice to this receiver’s size: The AVR-4520CI is unmistakably huge, a Paul-Bunyan sized receiver if there ever was one. With dimensions of 17.1 inches wide x 7.66 inches high x 16.64 inches deep, the 4520 has some bulk to it. Thankfully, Denon hides that bulk well by encasing the works within a streamlined chassis and a simply-adorned front panel. “Uncluttered” is the word that kept coming to mind.

In fact, the front panel is so completely uncluttered that the only visible controls are a power button and a pair of large input and volume knobs. The knobs flank an inset, centrally-positioned, large-size display window and a drop down panel directly beneath it. It’s only when you open the panel door that you see where all of the lesser-used controls are hiding. Props to Denon then for improving its receivers’ overall aesthetics. It’s turned out a few ho-hum looking designs over the years, but the AVR-4520CI ain’t one of them.

Once we completely unboxed the receiver unit, we also found inside the box: a universal-type remote control and two AA batteries to go with it, a detachable IEC power cord; AM and FM antennas; an Audyssey setup mic; Easy Setup guide; and a CD-ROM manual. Like many others, Denon no longer includes a full paper manual with the AVR-4520CI, but one can be downloaded online or printed from the CD-ROM.

Features and design

Like many up-market receivers these days, the Denon AVR-4520CI comes equipped with a dizzying array of features to accommodate all manner of systems. It sports 9.2 channels of power that’s assignable for single or multi-room configurations, and its amplifier section is rated at 150 watts per channel with two channels driven into a full-bandwidth, 20 Hz-20 kHz rating. The receiver also features 11.2-channel expandability should your system grow beyond the onboard capabilities.

That seems unlikely, though, given that the Denon AVR-4520CI also includes simultaneous four-zone, four-source stereo audio outputs for multi-room, multi-zone setup options. The receiver is also equipped with dual-zone, dual-source, HD video outputs to go along with its multi-zone audio options. Seven HDMI inputs are included as well, one of which resides on the front panel for quick access.

From the get-go, the Denon impressed us with its smooth, listenable treble that made long-term viewing sessions fatigue-free

Speaking of video features, the Denon AVR-4520CI also comes equipped with 3D and 4K video pass-through and 4K up-scaling of all video sources for compatibility with current and future high resolution formats. Unfortunately, we didn’t have a 4k video system on hand to test the Denon’s capabilities in this regard; Once 4K video becomes a mainstream reality though, this sort of future-proof design can only help the Denon stave off any impending obsolescence.

The Denon AVR-4520CI also includes a full-suite of Audyssey features to help calibrate the sound in your room. Dubbed Audyssey Platinum, the suite includes the usual MultiEQ XT32 equalization, Dynamic Volume and Dynamic EQ features along with a host of other Audyssey-derived enhancements, such as Sub EQ HT and LFC. Each of these is designed to help improve bass quality for dual sub setups and late night listening, respectively.

These days, no top-end receiver would be complete without Apple’s AirPlay technology, a feature that’s included in the AVR-4520CI. The Denon also includes DLNA 1.5 certification, HD Radio, and support for streaming services such as Spotify, Pandora, SiriusXM internet Radio, and vTuner internet radio.

Denon AVR 4520ci AV receiver front screen angle

While the Denon has many more features under its bonnet, they’re too numerous to list here; see the manufacturer’s website or manual for full details. Suffice it to say, we came away impressed with the depth and breadth of the AVR-4520CI’s feature set. It’s both comprehensive and well-thought out, a claim not all top-tier receivers can make.


Once we placed the calibration microphone in the correct positions, total auto setup time using the built in Audyssey system took about 45 minutes. Compared to our usual experience, this is somewhat longer than average by about 25 minutes; most of the added time was due to a glitch in the program we couldn’t initially get around.

Why Denon’s automatic setup program is so difficult is beyond our comprehension.

During our calibration run-through, we found that the AVR-4520CI defaults to a dual subwoofer arrangement, even if you only have a single sub hooked up. When it sends tone bursts to the subs and gets feedback from one sub and not two, Denon’s auto-cal flashes a warning to this effect and does not let you proceed until you rectify the situation—meaning it must see a second subwoofer signal. Moreover, the receiver doesn’t provide a clear way of changing the auto setup protocol from expecting two subs to just one, at least as far as we could tell. Yikes.

After spending about 10 minutes combing through the manual and the receiver’s setup menu, we still couldn’t find an easy way to default Denon’s version of Audyssey to expect only a single sub. We then tried running another sub cable from the receiver’s second sub output into our subwoofer’s left input so that we could trick the receiver into thinking there were two subs in the system.

Our workaround was a success: We were granted permission by the almighty auto setup program to proceed. After we completed calibrating our system, we went back into the receiver’s speaker menu settings and changed the dual sub configuration back to one. Thankfully, everything still worked just fine. Why Denon’s automatic setup program is so difficult is beyond our comprehension. In our experience, it is hands down the most irksome auto-cal routine we’ve ever used; be prepared to perform a little Tomfoolery if you’re purchasing the AVR-4520CI and have a single subwoofer in your system.

Per our usual practice, once we completed the auto setup program, we went back into the receiver’s manual setup menu to double check its settings. Audyssey wasn’t quite correct in setting our Aperion Verus tower fronts to full-range and crossing over our Verus Dipole surrounds at 200Hz, so we changed both pairs to 60Hz and 150Hz, respectively.


To fully put the Denon receiver through its paces, we used it with a variety of gear, including: A Samsung UN40C6300 LED TV; Samsung BD-C5500 Blu-ray player; Denon DCD-CX3 SACD player; HP Pavilion G6-2320DX laptop; Apple iPhone 4; Bowers and Wilkins P5 headphones; and Aperion Audio Verus Forte surround loudspeaker system.

We let the Denon AVR-4520CI break in for a good 40 hours before doing any serious listening, but once that was over, we immediately fired up many of the same bombastic, action-driven movies we usually test receivers with, such as the 2009 version of Star Trek, Quantum of Solace, and The Dark Knight, all on Blu-ray.

…we could tell that the AVR-4520CI’s midrange sounded heavily compressed, flat, and lifeless, especially with densely-recorded albums.

Let’s start with what this receiver did right. From the get-go, the Denon impressed us with its smooth, listenable treble that made long-term viewing sessions fatigue-free. Even without Audyssey MultiEQ activated, we could listen to things like gun shell clinks, sibilant vocals, and high-impact cymbal crashes all day long and never tire of them.

Bass, too, sounded good. Explosions and car chase scenes from both The Dark Knight and Quantum of Solace had much of their high-octane impact come through effortlessly via the AVR-4520CI, sounding appropriately rich and weighty and with a tactile yet articulate quality to it.

We would like to note though that the Denon’s deftly-handled bass was limited to its quality only and not its quantity or magnitude. In other words, the AVR-4520CI’s dynamic range capabilities seemed stunted in comparison to other receivers in its price range. Sticking with the same action Blu-rays mentioned above, we found that the Denon didn’t have as much sudden and explosive impact, nor as convincing volume gradations from soft to loud, as we were used to hearing, especially given its rated power. Indeed, we’ve heard other receivers in the Denon’s price range sound punchier and more dynamically startling overall.

Moving on to “Little Fly,” from Esperanza Spalding’s album Chamber Music Society, we enjoyed the way the Denon receiver let a good chunk of the fulsome, round-toned goodness of Spalding’s upright bass come through loud and clear, with fine pitch definition and tonal texture.

Denon AVR 4520ci AV receiver audio inputOnce we focused on the Denon’s midrange quality however, we started noticing all the ways in which it came up short compared to the competition. Spalding’s vocals on “Little Fly” sounded too far back in the mix. Her scat solos and brilliant falsetto also sounded far less powerful and open than what we typically hear from other similarly-priced receivers, almost making her sound timid in her delivery.

We then tried watching scenes from our favorite dialog-driven films, such as Casablanca, Amelie, and The King’s Speech, again all on Blu-ray. While lower level auditory information was still clear, we found that many of the nuanced sonic details we were used to hearing from these movies, such as breaking glass, shuttering windows, and various other Foley effects, had much less detail, presence, and impact through the Denon than they did with other receivers we’ve tested.

The AVR 4520C…had a way of heightening the visual impact of every movie that passed through its HDMI ports.

What’s more, the Denon’s midrange repeatedly sounded recessed compared to the rest of the sonic spectrum. Thom Yorke’s vocals on Radiohead’s King of Limbs and In Rainbows sounded somewhat lost in the mix; Yundi Li’s piano from his Liszt album also had less brilliance and presence from middle C upward than we’re accustomed to hearing. These were the same type of drawbacks heard on the Spalding album, and we continued to hear them with every movie disc or music album we tried.

Initially, we thought we might have just needed to rest our ears a bit, so we decided to step away from evaluating the Denon for a few days. Unfortunately, that didn’t help matters much. Again, we could tell that the AVR-4520CI’s midrange sounded heavily compressed, flat, and lifeless, especially with densely-recorded albums.

The longer we listened to the Denon AVR-4520CI, the more we felt we were missing much of the detail, timbral richness, and tonal development we’ve heard through some other receivers. At first blush, it may be easy to think of the AVR-4520CI as a receiver that performs well at the lower and upper ends of the frequency range, just missing the mark on that little bit in the middle. Unfortunately, the auditory ramifications are far greater than that.

Approximately 70-80 percent of the sonic information contained within most music and movie recordings lies in the lower mids to lower treble region of the sonic spectrum. This means the Denon AVR-4520CI, in our opinion, just isn’t correctly reproducing the majority of sounds we hope to get our auditory kicks from. Perhaps paraphrasing the late Stereophile founder J. Gordon Holt best sums up how important the midrange is to sound reproduction: “If you don’t get the midrange right, nothing else matters.” And indeed, throughout the months we had to audition it, we just couldn’t get over the AVR-4520CI’s consistently flawed midrange, no matter how hard we tried.

Functionally, the AVR-4520CI had quite a bit going for it. It operated as well as other receivers in its price range, save for its rather eccentric way with subwoofer auto-calibration. Once we got to using it on a regular basis, we were able to access its networking and applications features instantly and without a hitch. What’s more, our iPhone 4 found the Denon receiver straight away and had us streaming tunes in no time flat.

Denon AVR 4520ci AV receiver front controlsLastly, we’d be remiss not to mention the Denon’s outstanding video processing capabilities. Watching that same Quantum of Solace Blu-ray, we kept noticing how fine details, such as the rain drops and architectural grid patterns of Mitchell’s apartment building from chapter 5 of Quantum of Solace, stood out in greater relief than we’ve ever seen from a receiver this side of $2500. The AVR 4520CI just had a way of heightening the visual impact of every movie that passed through its HDMI ports. Even low-res DVDs looked better than we’ve ever seen them.


On the surface, the Denon AVR-4520CI makes a pretty strong case for itself as a flagship receiver. Its combination of relevant features, consistent and reliable operation, and a straightforward user interface makes interacting with it on a daily basis a fairly pleasurable task. Its multi-room audio/video capabilities would also serve a whole-home, networked system well. It’s the combination of these features, and the numerous others that are part ‘n parcel of the AVR-4520CI, that make it one of the best equipped A/V receivers out there for the price.

Unfortunately, these features can only take the Denon so far: It’s a different story once performance quality is factored in. In other words, there’s just no getting around the fact that the Denon AVR-4520CI faces some pretty stiff and sonically superior competition in its price class. For example, the Yamaha Aventage RX-A3020, which we recently reviewed, has noticeably better transient response, resolution of attack and decay components, and more complete development of both midrange information and macro and micro dynamics.

Even the Marantz SR6007 we reviewed a year ago sonically outclassed the AVR-4520CI. We found its smooth, refined, and audiophile-quality sound much more pleasing for both the music and movie lover in us. Plus, its midrange is to die for, so if you’re primary concern is performance quality over features, the lower-priced Marantz wins out every time in our book. Considering that both Denon and Marantz are owned under the D&M corporate umbrella, we find it somewhat perplexing that two receivers sharing many of the same manufacturing resources can represent entirely different levels of value and performance.

Perhaps it’s that reflexive need to think of other receivers and tune out the Denon that best sums up our experience for the duration of our time with the AVR-4520CI. We literally spent months evaluating it, and the whole time we found ourselves wishing we had something else in the chain. Try as we might, we just couldn’t build a case for choosing to purchase the Denon AVR-4520CI over the competition.

Bottom line: Unless the Denon AVR-4520CI’s features are exactly what your system needs, we’d recommending looking elsewhere for a top-tier A/V receiver.


  • Smooth, fatigue free treble
  • Good bass clarity and definition
  • Well-thought out feature set
  • Outstanding video processor


  • Audio performance outclassed by the competition
  • Sound lacks dynamics and punch
  • Recessed, flat, and lifeless-sounding midrange
  • The most irksome auto set up program we’ve used yet

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