Sennheiser CX 400-II Precision Headphones

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Sennheiser CX 400-II Precision Headphones

With superior musical detail resolution across the board and more precise dynamics, the CX 400-II Precision ear-canal phones target music fans wanting...

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Review of "Sennheiser CX 400-II Precision Headphones"

published 21/05/2010 | Hishyeness
Member since : 09/03/2009
Reviews : 214
Members who trust : 184
About me :
Checked Out. May pop back in from time to time. Best wishes and good luck. 8^)
Pro Rich audio, great noise isolation and excellent value
Cons In-ear format may not be everyone's cup of tea. Rustling from cable.
very helpful
Sound & Volume
Durability & Robustness
Value for money

"The Art of Senn"


I have been happily and contentedly using a pair of Sennheiser CX300 headphones for the best part of two years now, so when I recently acquired a netbook, I decided to relegate them to my laptop bag and invest in some new, upgraded headphones for my iPod. I toyed with the idea of getting a like for like replacement (the CX300 has been upgraded to the CX300 II) but I found that the next pair up on the product ladder were available for just a few pounds more, so I opted for the CX400 II instead.


The CX400 comes in the sort of heat sealed plastic packaging that seems to need steely determination, surgical implements, sheer bloody-mindedness - or a combination of all three - to get into. Once you do manage to get it open, you will find the headphones themselves, a “cable winder”, six pairs of soft rubber inserts of varying size and style, a discreet Sennheiser-badged cable clip and a small leather-effect pouch for storing the headphones.

These in-ear headphones isolate noise and deliver their sound by creating a soft rubber seal in your inner ear. As such, to work at their best, you will need to ensure that you insert the right size rubber insert onto the headphones. This will, of course, vary from person to person, but with six different choices, you are bound to find a decent fit. It’s all a matter of trial and error, but fortunately, the inserts push onto and off the small ear buds quite easily. The matt black cable is approximately three feet long from the L-shaped 3.5mm jack to the ear buds. The buds themselves are small, glossy black numbers with a chrome effect trim and Sennheiser branding. There is a discreet “L” and “R” on each of the ear buds, although in reality, there seems little practical difference which ear you plug them into.

Unlike their antecedents (my CX300’s) the CX400 has the added bonus of an in-line volume slider which sits a couple of inches below the V-splitter for the individual right and left ear buds. When I read the product description on Amazon, I was intrigued by the promise of a cable winder. However the widget provided was not at all what I expected. It’s a rectangular piece of soft, foamy rubber with two deep dimples at one end, set in series which hold the ear buds - and a notch at the other end that holds the wires taut. You then wrap the remainder of the wire around it. The idea is that the cable doesn’t get tangled, and although it works surprisingly well, I find it too much of a hassle and end up winding the cord around my iPod instead.

Provided you have chosen your ear bud inserts wisely, you will be rewarded with a rich aural experience. The rubber seal blocks out a surprising amount of extraneous noise, which means your music (or spoken word) does not have to compete with outside sounds. The bass is deep and resonant, adding real depth to music and reproducing the booming SFX in shows like 24 and The Pacific quite realistically. The treble tones are pronounced without being shrill or tinny, but distinct enough not to be swallowed up by the bass. In short, these are excellent all round performers from a technical standpoint.

There are, however, one or two caveats. Firstly, blocking the ear canal means that sounds you do not normally hear – like swallowing, chewing, and even walking are greatly amplified and become noticeable with these earphones plugged in. Secondly, the cable itself will conduct noise as it rubs against clothing, which again, reproduced an audible rustling. As such, these buds are patently unsuitable for sustained physical activity, not least because as they have a habit of slowly popping out if your ears get too sweaty. That said, I regularly use them during my daily commute to work, during which I spend at least forty minutes walking. The rustling becomes less of an issue if you shorten the cable and make sure it doesn’t swing back and forth (the adjustable cable clip which is provided makes a significant difference) and a slightly higher volume makes footfall much less audible. To be frank, just like any kind of background noise, your ears tend to tune them out as you get used to it.

One of the reasons I opted for these CX400’s instead of the improved CX300 II was the in-line volume control. If you download MP3’s from online sources and upload CD’s to iTunes, you will know that the default volume settings of tracks can vary greatly (I find stuff from the Eighties is generally lower in volume). It can be irritating to pull out your iPod to adjust sound levels, so having a quickly accessible slider is a bonus. However, whilst the idea of having it is welcome, it is let down somewhat in the execution. The slider is quite stiff, making it very difficult to adjust in small increments. When it does slide, it’s too easy to push it to maximum volume. I have also noticed that there is little variance in volume from minimum to about 90% of the way up the slider, then all of a sudden, it gets quite loud. Given the size of the slider, this represents not much more than the thickness of a thumbnail.


I bought my pair from Amazon for £18 (its currently fluctuating around the £20 mark) and was astonished that the advertised RRP is £59.99. Although these earphones are very good replacements for standard white iPod headphones, they certainly do not justify the full asking price. The price paid represents much fairer value and I could only happily recommend them if you manage to get hold of them at under £20.

© Hishyeness 2010

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Comments on this review

  • shoppingpenguin published 18/10/2010
    Thorough review; I do find they vibrate a lot when i'm walking (or maybe stomping) around
  • Alyson29 published 10/10/2010
    These look and sound good x
  • mattydalton published 02/08/2010
    I must have the 300's as I don't have the in line volume controller. Truly superb earphones though.
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Product Information : Sennheiser CX 400-II Precision Headphones

Manufacturer's product description

With superior musical detail resolution across the board and more precise dynamics, the CX 400-II Precision ear-canal phones target music fans wanting to upgrade the sound quality of their portable audio devices. The wide array of ear adapters provided in the package allows for a personalized fit as well as an excellent passive attenuation of ambient noise. To add to your listening convenience, a volume control has also been integrated into the cable.

Product Details

Product Description: Sennheiser CX 400-II Precision - headphones

Product Type: Headset

Recommended Use: Game console, portable audio system, mobile phone

Colour: White, Black

Headphones Type: Headphones - binaural, Headphones - stereo

Headphones Form Factor: In-ear

Connectivity Technology: Wired

Sound Output Mode: Stereo

Audio Specifications: Frequency Response 17 - 22000 Hz - Sensitivity 114 dB - Impedance 16 Ohm

Manufacturer Warranty: 2 years warranty

Dolby PL / AC3: without Dolby PL / AC3

Earclip: No

Type: In Ear Headphones

EAN: 0615104167483, 0615104167445, 4044155043075, 4044155043068

Noise Cancellation: without Noise Reduction

Neckband: No

Signal Connection: Wired

Ear Canal Headphone: Yes

Manufacturer: Sennheiser


MPN: 502745, 502743

Product Type: Headphones

Colour: White, Black

Recommended Use: Game console, portable audio system, mobile phone

Features: Volume control


Headphones Form Factor: In-ear

Headphones Technology: Dynamic

Connectivity Technology: Wired

Sound Output Mode: Stereo

Frequency Response: 17 - 22000 Hz

Sensitivity: 114 dB

Impedance: 16 Ohm

Magnet Material: Neodymium


Connector Type: Headphones ( mini-phone stereo 3.5 mm )


Cables Included: Headphones cable - 1.2 m

Included Accessories: Carrying pouch, cord clip, cable winder, ear tips kit

Manufacturer Warranty

Service & Support: 2 years warranty

Service & Support Details: Limited warranty - 2 years


Listed on Ciao since: 09/02/2010