Sennheiser MX400 Mini Review


Some time ago, I was browsing a few of my favorite sites when I came across a deal for two pairs of the MX400 earbuds. The price was right and given my lack of quality earbuds, I decided to jump on this deal, if only to have a decent pair of earbuds I can use to listen to my music at times where isolation from the surrounding environment is not quite ideal. When I received them after a few days, I began burning them in as per my usual, listening to them intermittently throughout the process. What I heard was actually quite surprising.

Design and Build Quality

Constructed entirely of plastic, the housings of the MX400 don’t exactly inspire confidence and feel rather cheap to the touch. The plastic cabling is quite tangle-prone and isn’t quite as soft or flexible as I would’ve liked and terminates in a nickel-plated 3.5mm straight jack. As a whole, the MX400s don’t seem like they would be able to stand up to a great deal of abuse and should be toted around in a case, if at all possible.

Sound Quality

As I said from the start, I was more or less expecting decent quality from the MX400s; nothing spectacular nor particularly bad. What I did not expect was to be blown away by the sound of the MX400s but, here I am. These are, quite easily, the best sounding earbuds I’ve ever heard and to explain why, I’ll start at the bottom.

The way the MX400s present bass is very polite and controlled. It’s punchy enough to make itself known when it needs to be and never rises up unnecessarily. Speed is certainly a strong suit of the MX400s and can come and go quite easily. Perhaps that is the Achilles’ heel of the low end presentation because it doesn’t seem to have realistic levels of decay and once bass has hit, it seems to disappear just as quickly. These can definitely be described as bass light overall but that can be augmented with a warm sounding amp or even a cheap Fiio E3.

The midrange brings to the table nice detail and transparency. Vocals take center stage in the presentation, seeming to sit in front of the instruments. Treble is very smooth and somewhat laid back, lacking the type of sparkle and crispness that I’ve grown to enjoy from IEMs such as the RE0.

The soundstage is what wowed me the most about the MX400s. Both width and depth are very impressive and created an “out of head” feeling, as if the music was coming at me from outside of the earbuds themselves. Due to the large soundstage, the MX400s are adept at presenting distance between instruments, and good at spatial positioning within the soundscape. The best aspect of the soundstage is that it’s large without being too large. I never got the sense that I was disconnected from the music; on the contrary, the MX400s were surprisingly intimate with most tracks.

I did find that there’s noticeable graininess and dryness throughout the presentation. This is perhaps the biggest flaw of the MX400s. Notes are harder and edgier than I prefer and while this may be a bit of a drawback to me, some users may enjoy this for certain Hard Rock or Metal tracks. In addition to this graininess, the MX400s have a somewhat cold, almost analytical, sound about them which is decently resolving but not the most natural or “musical” sounding.


The MX400s are the best purchase I’ve ever made in terms of earbuds, blowing all of the other earbuds I’ve tried (which isn’t much, admittedly) out of the water. Sure, these have their flaws but given my relatively low expectations, I’m very pleased with these earbuds. Considering that these are several years old and have since been replaced by the slightly higher end MX580s and Sennheiser’s new “Expression” line of earbuds, I’m confident that sound quality will only improve as you move up the ladder. Personally, I’m more of a fan of IEMs than earbuds for a number of reasons but if I were currently in the market for a new pair of earbuds, I’d definitely start with Sennheiser’s.

Nonetheless, the MX400s have delivered on everything I wanted them to. They sound better than decent, were extremely cheap and I don’t have to worry about babying them too much. The MX400s can be found online for cheap and I can definitely recommend them to people who need a cheap knock around pair of earbuds.

About Justin McBride

My name is Justin McBride and I’m a guy who enjoys writing, playing games and writing about playing games. Sound lame enough yet? Well, I have other interests as well such as hanging out with friends, watching TV, going to the movies from time to time, surfing the internet, listen to good music, drive at speeds I shouldn’t be driving at and so on. The problem is, that’s all stuff everyone likes to do, so why write about it? Oh wait, seems I just did. Oops.

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