Denon AVR-4520CI A/V Receiver

Audio Performance
Video Performance
PRICE $2,499

Top-drawer room correction
Strong dynamics
Bounteous custom features
Bluetooth requires accessory

The Denon AVR-4520CI and Audyssey MultEQ XT32 room correction combine to produce a close to perfect-sounding receiver.

Denon and its sister brand Marantz are among the most popular A/V receiver makers. The AVR-4520CI is Denon’s top-of-the-line model, the brand’s best shot at building every feature worth having into a nine-channel powerhouse. It does not attempt to be all things to all people (Bluetooth users, for instance). But it does offer a feature set that is strong in custom integrator features; hence the CI designation in the model number. And, as I discovered in this review—you won’t mind if I give away the ending, will you?—it also offers the best implementation of Audyssey room correction I’ve ever heard. Room correction has always seemed like a great idea, but the results have been hit or miss. Here it consistently produced great sound.

Heavy Metal
The front panel may not be stylish, but it is metal, not plastic. With the flip-down door closed, the only visible button is for power, while two knobs select inputs and adjust volume. But behind the door are four strategically selected input buttons—for Cable, Blu-ray, Game, and Network—along with the expected navigation controls and more buttons that select, activate, and deactivate the three extra zones. Front-panel jacks include MHL-compliant HDMI for streaming from an Android device, along with iOS-capable USB and the usual suspects.

Lackluster remote controls are a common weakness of pricey receivers. Here, Denon goes the extra mile. This learning remote differentiates controls by size, shape, and color. Its handsome green backlight illuminates the keys and the 1.4-inch-wide liquid crystal display. Just touching the remote triggers the backlight—wonderful! Four macro keys at bottom allow automating of control sequences. The only possible way to improve this remote would be to turn it into a Web-programmable USB remote. If you don’t like traditional remote handsets, the Denon Control App is available for both Android and iOS devices.


Denon provides one out of three possible wireless connectivity options: Apple AirPlay. That enables iOS devices to stream to the receiver through your home network. Unlike many other AVR makers, Denon does not provide Bluetooth in this model, and its Website does not even list a Bluetooth adapter. Inexpensive adapters from other manufacturers are available, of course. Wi-Fi is also absent as both a feature and an add-on. However, this CI-hip receiver does have a built-in four-port Ethernet switch. Connect one to your router, and you’ll still have three left to connect a wireless bridge along with, say, a Blu-ray player and a Smart TV.

The three HDMI outputs include two parallel outputs and one discrete output dedicated to zone four. That means the receiver can switch two separate HDMI feeds at the same time. It can also pass an HDMI signal when in standby. Video processing includes both 3D and 4K passthrough and 4K scaling.

The full suite of Audyssey audio tools starts with MultEQ XT32, the most advanced of Audyssey’s four auto setup and room correction systems, with the finest filter resolution. Its interaction with Denon’s amp proved crucial to the product’s performance—more about that later. If you’re using more than one subwoofer, Audyssey SubEQ HT factors that into the room correction. Audyssey Dynamic EQ and Dynamic Volume provide definitive volume leveling and low-level listening enhancement. If you need to trim bass frequencies to relieve neighbors of through-the-wall boom, Audyssey LFC is included.

Finally, Audyssey DSX offers the potential of both height and width soundstage enhancement. With this receiver’s nine amp channels, you can run two of the following four options along with your standard 5.1-channel setup: height, width, or back-surround channels, or biamping of the front stereo channels. The back panel’s 11 sets of binding posts allow three of the four to be hooked up at once, enabling you to switch among them as desired.


The DLNA protocol handles media sharing from networked PCs and other devices. This receiver is also certified for the Windows 7 Play To feature, enabling you to route music streaming from a PC to the receiver via Ethernet. Play To also works in Windows 8. Other network audio options include vTuner Internet Radio, support for Sirius XM, Pandora, and Spotify audio streaming services, and the Flickr photo-sharing app.

Denon’s setup assistant guides the user through every back-panel connection in addition to running the Audyssey auto setup. Audyssey MultEQ XT32 includes a nifty feature that lets the user dial in the sub volume setting most suitable for the room correction scheme. Everything ran uneventfully, and I made my usual tweaks, designating the speakers as small and specifying an 80-hertz crossover.

Associated equipment included five Paradigm Reference Studio 20 v.4 speakers, Paradigm Seismic 110 subwoofer, Oppo BDP-83SE universal disc player, and iPad mini (Retina version). All movie demos were on Blu-ray Disc.


6311's picture

Get serious invest in receiver without DisplayPort 1.2 or hdmi 2.0 Not serious

miller68ny's picture

I've read reviewers, possibly you, comment on how these room correction software improve on the sound of a receiver and I couldn't agree more. I purchased an Onkyo AVR after reading many reviews but wasn't thrilled with the way my Paradigms sounded. The old Sony AVR was much richer in the midrange and better integrated with my subwoofer. Only after I ran it through the Audyssey EQ did it approach the sound of the Sony. The manual even recommended running the MultEQ as the first step of the speaker set up so this begs the question, why did I just upgrade? If the sound of my old clunker sounded better with my speakers right out of the box, why did the Onkyo need all this processing to sound close to an AVR that clearly was it's inferior? Can we just make do with a middling AVR just as long as it has killer room correction?

Mark Fleischmann's picture
I once asked the Audyssey people whether their room correction systems would compensate for flaws in amplifier design -- in other words, would it flatten out an amp that didn't measure flat? They said yes. However, in practice, I still find that room correction interacts with amp design in unpredictable ways. In this case, the amp needed room correction to provide adequate detail and imaging. In other cases, I've found that room correction firmed up detail but at the expense of comfort, especially with music. My best advice is to buy a receiver based on a good-sounding amp -- that is, one that sounds good when all the enhancements are stripped away. Your room may respond to correction differently than mine. And you may want to use it only with certain content or not at all.
biaubill's picture

I have an Integra DHC-80.3. Setting up my speakers (which are full range) with the XT32, it set cross-overs at 40hz (L,R), 45hz (C), and 45 (LS, RS). Why did you set your crossover to 80hz?? I read the same thing on various forums about setting the cross-over to 80hz to utilize better bass management, but I just don't get it why. Isn't setting it to where the XT32 wanted it appropriate? I understand you used bookshelf speakers for your demo, so would it be appropriate to set the crossover to 80hz for full range speakers? Also, what other tweaks did you do on the receiver? Thank you the excellent review! I look forward to you reply.

Mark Fleischmann's picture
80Hz is the crossover recommended by THX though that's not the reason I stick with it. I use it because my speakers have limited bass response (which is not the same as no bass response) and they begin rolling off below that point. Most room correction systems detect them as "large" speakers, but that leaves a notch in bass response where the rolloff begins, so I reset to "small" and 80Hz. To determine whether this is right for you, find some reviews of your speakers with measurements (if possible) and determine where they roll off bass. If your speakers have more bass than mine, you might prefer a lower crossover; if they have more bass than mine, you might prefer a higher crossover. The other consideration is how much bass your receiver can handle before it goes into clipping. If a low crossover makes your receiver clip, you may need to use a higher crossover to give it an easier workload, avoid clipping, and improve dynamics.
mnc's picture

Mark, I'm very curious how this sounds compared to the Marantz 7008?

Mark Fleischmann's picture
While I didn't have them in the room for a direct comparison, in general Marantz had a better-sounding amp once all the room correction and other digital enhancements were stripped away.
palmharbor's picture

Since the Japan Nuclear issue...production for both units are in the same factory using the same parts. I know this for a fact.

palmharbor's picture

I have owned the AVR 4310 CI for a year now and I am totally pleased with it...its easy to set up, telephone support is great, you do not wade through 10 different selections. I used to have Emotiva separates but had problems with getting the subwoofer to work and they were not able to fix it. I would recommend this unit highly.

PeterC's picture

Wouldn't the AVR 4520CI be a better comparison to the Marantz AV8801 which also has XT32 processing ( I realize that it would require a separate amp)?
I have been considering the AV8801 based on the great review by S and V.
How would the 4520CI compare to this Marantz?

Macahan's picture

Mark, I have a pair of PSB Stratus Silver speakers that I bought in the 90's which are bi-wired with a Definitive Tech Supercube 8000 sub, just a simple 5.1 system. When I run the Audyssey program it wants to set the PSB's as large and full band. I called up a local installer and said if you have a sub are you not supposed to run them as small? He said not if they are bi-wired and also said that audyssey made the right call. What do you think?