Review: Denon AH-C400 – Beautiful Looks, Beautiful Sound

Denon | In-Ear Monitors | $ 349.99

A unique diecast zinc housing follows a monochrome color scheme that shines bright and catches the eye. Twin drivers in each housing powers the sound straight into your ears. These are the Denon AH-C400 Music Maniac headphones. Denon recently updated their line of headphones with offerings to a vast majority: the frequent traveler, music enthusiast, bass-lover, and active-folk. The C400 is their IEM model for the music-lover.


  • Driver: Dual Balanced-Armature
  • Frequency Response: 4 Hz – 20 kHz
  • Impedance: 430 Ohms
  • Sensitivity: 106 dB

In the Box

  • Denon AH-C400 Music Maniac IEMs
  • Ear Tips (Comply Foam: M; Silicone: XS/S/M/L; Double-filled Silicone: S/M/L)
  • Leather Carrying Case
  • Karabiner
The Denon headphones come with the minimum of accessories to get you started.


As I stated earlier, the C400 feature a beautiful zinc diecast housing that shines brightly, but it’s the unique design that will turn heads. A monochrome silver housing with black accents, the one-off design of the C400’s black balls and oblong, bent figure is what will set eyes off. It looks like something that came straight out of the future. The design itself is different, but still attractive.

The design behind the AH-C400 is very one-of-a-kind indeed.

Design: ★★★★


These Denon IEMs have a slight V-shape to their sound. A small dip in the mids allow the tight, quick bass to shine well as well as well extended treble that takes after their design; metallic. The mids are sweet and clear. Overall, the Denon IEMs do well to be enjoyable without the need to become clinical.


The bass on the Denon has a slight mid-bass emphasis. The end result of this is a low-end that is very tight, punchy mid-bass. Bass impact is better than most, but can use some slight improvements here and there. The bass does have very good depth though as it can reach down low and reproduce sub-bass textures with great accuracy and musicality. The bass isn’t the focus of these IEMs and it pairs well with the midrange.

Bass: ★★★★½


Detailing in the lower midrange is beautifully rendered by the AH-C400. Guitars strum with authority with a sense of realism behind them. The upper mids show strong clarity without becoming over-bearing like a pair of Etymotics. Instrumentals become very lively with the 400, it’s very enjoyable. Vocals have a small sense of sweetness, but almost completely lack lushness and depth. The vocals, in turn lack some dynamics while the instrumentals have absolutely gorgeous dynamic.

Mids: ★★★★½


Detailing and clarity in the upper-end are real strengths of these IEMs. The lower-end treble snaps with great presence and power. A good presence really does this area well, a part of the spectrum a lot of headphones forget about. Moving on up, the detailing remains strong as the upper-treble extends high. The result is a dominant sparkle that contains much energy to them. However, A metallic tinge, which produces some sibilance, may be a turn off to some listeners.

Highs: ★★★★½

Audio: ★★★★½


Denon supplies a very luxurious case with their Music Maniac AH-C400 IEM. The case is made out of protein leather with a semi-hard shell. It’s well-made and adds a huge sense of quality behind the headphones, that already have a nice feel to them. The case zips open to reveal a pouch on the inside for an accessory or two. The case will be good safekeeping while the C400 aren’t in use.

The supplied case is made of protein leather and will protect your IEMs well.

The housings, as stated for the third time, are zinc diecast. That said, the housings are very tough and will take a licking and live to tell the tale again. They will do a fine job protecting the 2 drivers they each house. A large strain relief sticks out of each of these housings to ensure that the cable connection won’t be lost.

The metal housings are dense, shiny, and strong.

The cable is reinforced with a plastic coating on the exterior. This makes them feel a lot stronger than most cables. Although they aren’t too flexible, the cable does have a nice stiffness to it that is partially due to its thickness. The cables are thick enough to have a quality feel, but thin enough for portable use. It’s really well-made.

The cable quality is one of the best I’ve seen, but it isn’t too flexible.

At the end of that cable is another long strain relief. Denon tries to make sure that cable failure isn’t a huge possibility with these strain reliefs (the cable unfortunately isn’t removable). Additionally, the headphone jack comes as a 90-degree angled jack. Add in gold plating and we have a perfect build for these headphones.

A perfect headphone jack adds to the perfect build of these Denon IEM.

Build: ★★★★


Despite the denseness of the housing, they remain fairly lightweight. The C400 offer flexibility as they can be worn both up and down very comfortably. Microphonic cables may be problematic for some that wear the headphones down. Wearing them up sets the microphonics to a tolerable level though. Denon offers 8 total tips for users to experiment with to ensure the utmost comfort.

Denon offers regular silicone tips, filled-silicone tips, as well as a medium Comply for listeners to use.

Comfort: ★★★★


The AH-C400 are Denon’s flagship IEM model, so they really aren’t cheap. These IEMs come in at around 350 dollars, not the priciest IEMs I’ve tried, but not cheap either. For the price, you do get a very well designed product that offers great audio quality that is competitively priced. They are built well; despite not having removable cables, they should last a while. They may not be the best bargain in the bin, but shouldn’t be passed up either.

A 3-button remote and mic is also attached to the cable for iDevice users. Additionally, Denon also has a number of apps available on the App Store that act as music players. The Music Maniac app has a nice EQ. The app is free and doesn’t require Denon headphones to use. They do feature EQs for the Music Maniac headphones as well as the little white ‘buds.

The Denon Audio app features EQs for a variety of things, including their headphones and the Apple Earbuds.

Value: ★★★★½

Final Thoughts

Denon did a great job with these IEMs. They are well balanced overall with a nice treble focus, but aren’t clinical. The sound does have a frill or two associated with it, but overall, a very enjoyable IEM to listen to at home or on the go. The design is sure to catch eyes, but who cares when you have music pouring into your ears.

I’d like to thank Laurent for the product loan.

Overall Score


Denon Music Maniac AH-C400

† All prices are in US currency.
This review was written by the Review Team. Cumulative scores are rounded to the nearest half or full star.
This accessory, product, or app was received as a sample. Thanks Lauren for the product sample.
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