Review: Denon AH-C820 Headphones

Review: Denon AH-C820 Headphones

Review: Denon AH-C820 Headphones

A few years ago Polk sent me a pair of Nue Voe earbuds for review (see Headphones Roundup: Polk Nue Voe, Phiaton MS 100 BA, and TunePhonik iZX5at iPhoneLife). They included memory foam ear inserts for improved noise isolation. They became my earbuds of choice for short flights because they were the only ones that worked well at keeping the noises of the engines at bay. On longer flights with more carry-ons I usually include my Bose Quiet Comfort over the ear headphones with active noise cancelation. Packing the bulky Bose headphones, however, often brought me back to Polk set for convenience and practicality—they were small, light and didn’t require batteries. Unfortunately, on a recent trip the volume control switch fell apart and the Polk headphones stopped working.

I reached out to the PR team at Sound United, the company that owns Polk, Marantz, Boston Acoustics and others, and they sent a replacement review unit, the Denon AH-C820 dual driver in-ear headphones. A quick look ahead: These will now be my go-to headphones for travel.


  • Solid Construction
  • Big sound
  • Well-designed
  • Comfortable to wear


In-app purchase required to enable sound tuning in the optional app.

Overall Review

Although the $199 AH-C820s arrived in a standard retail box, there was nothing standard about the earbuds under the cardboard packaging. The AH-C820s proved far from just replacements for the Polk Nue Voe.

Quality starts with the connector and the wire. The gold-plated connector fits snuggly in iPhone, Android and other standard 3.5mm audio jacks. The cable is thick and sturdy and incorporates what Denon calls a “Radial Cascade Damper system” to reduce cable-transmitted vibration noise. My only wiring question mark comes from neck detangler slider that seems more afterthought than a functional add-on. Between the included case and the cable design, the AH-C820 wires don’t generally tangle even when wadded into a pocket.

[note title=”Tradeoffs: Wired versus Wireless” align=”right” width=”350″]The real tradeoff with headsets like the AH-C820s comes in sound versus freedom of movement. No Bluetooth headset will sound as good as these earbuds, and they won’t run out of juice while you’re running—but they also make you carry your device around with you to listen, and they bring wires that can get tangled up in your chores.[/note]

The cables lead up to a pair of die-cast aluminum and resin buds that feature “Acoustic Optimizer” ports on the front and rear to help equalize air pressure.

The reason for air pressure equalization? Center to the AH-C20s design sit a pair of 11.5 Double Air Compression Drivers™  aligned in a row. These drivers move more air than single implementations.  The design allows them to punch out powerful bass with less distortion. The patented Denon design uses individual wires from the plug to each driver, which also increases the purity of the connection and the sound.

Denon AH-C820 Headphones
Denon Double Air Compression Drivers™

To double-down on the sound quality Denon includes memory foam Comply TX500 ear-tips to aid with sound isolation.

The earbuds fit vertically, somewhat like the Apple AirPods, with the cable descending which makes them more comfortable and less likely to interfere with activities beyond listening.

To round out the package, Denon includes a silicon wrap case for protecting the headphones during travel. A set of silicone ear inserts offer alternatives to the memory foam inserts. They also placed a small plastic clip to attach the wiring to your clothing—it’s likely the only part of the Denon ensemble you won’t care about—and you will probably lose it anyway.

Denon AH-C820 Headphones

Sound Profile

Like other earbuds and headphones, I tested the AH-C820s against the Audio Tests at with the following results.

ProductLow FrequencyTreble ExtensionDynamic RangeWiringBinaural Test
Denon AH-C82010 Hz14 Khz-84 dbClear Left/RightVery good. Could hear the sound vibrations in the virtual air.

The low Treble Extension may result from my old ears and not those of the earbuds. The test points out this possibility in its description.

I listened to a variety of music, from ambient nature sounds to Dido’s “White Flag,” to Led Zeppelin’s “Immigrant Song,” from Benjamin Britten’s Brandenburg Concertos to Mile’s Davis on Kind of Blue. If you listen intently, you can almost hear the acoustic track under the overproduction on the Beatle’s “Long and Winding Road.”

The playback was spectacular across the spectrum. Crisp highs with a bass that delivered like I installed a subwoofer in my head.

As I increased volume I quickly realized that the earbuds could handle sound that my ears could not. They will make you consider using volume-limiting if you don’t already use it.

Needs for improvement

AH-C820s don’t include a volume control, but after the volume failure on the Nue Voes the wisdom of design simplification reinforced itself—fewer moving parts, fewer failures.

Denon also shipped an app for their headphone and earbud enthusiasts. The Denon Audio Application for iOS and Android helps owners tune their personal sound profiles. The app contains an alternative interface to the iTunes of Play library, along with integrated access to TuneIn Internet Radio. Depending on your listening preferences, an alternative app may seem superfluous. Unfortunately, the one special benefit of the app, the personal tuning, requires an in-app purchase, and that’s why the app falls into the “needs improvement section.” People who buy $199 headphones should not need to drop another $1.99 to optimize their mobile listening experience. I get the price for non-Denon owners, but the AH-C820 should receive an app upgrade code in the box.

Review Wrap-up

With the AH-C820s Denon created a solid set of wired earbuds that deliver an outstanding aural experience.  The loud and proud comes housed in superior materials that should last for a long time. They should prove a worthy companion for travel or for just sitting on a couch on a Sunday afternoon blissing out to your favorite tunes.

This product was provided for review purposes.

All images courtesy Denon.

Daniel W. Rasmus

Daniel W. Rasmus, Founder and Principal Analyst of Serious Insights, is an internationally recognized speaker on the future of work and education. He is the author of several books, including Listening to the Future and Management by Design.

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