Unlike some earbuds, which are blatantly and obviously “voiced” to favor pop music’s driving bass lines, the DTX 101 iE tries to be more subtle. There’s still some mid-bass augmentation, but the bass boost isn’t as prominent as with some earbuds such as the Velodyne V-Pulse. As I mentioned earlier, you can use the fit to maximize the bass if you wish. And while you can alter bass somewhat, the slightly reticent lower midrange and traces of upper midrange spotlighting are permanent fixtures of the DTX 101 iE’s sound. Vocals, especially female vocals, come through with excellent decipherability, partially due to the paucity of lower midrange energy to obscure upper midrange detail. But the harmonic complement of most male vocalists sounded slightly bleached-out and lighter than neutral as a result of a deficit in lower midrange body and weight.

Even with a good fit, the bass response of the DTX 101 iE was slightly odd. The midbass had lots of thump and bloom, but the upper bass was somewhat lacking, giving bass lines a now-you-hear-it-now-you-don’t quality as they ascended. The lack of upper bass meant that the leading edges of bass transients didn’t seem as fast or defined as they were through my reference earphones. The bass was big, but with soft edges, like a big marshmallow.
High frequency response from the DTX 101 iE was smooth and reasonably extended. The lack of peakiness and rough edges means that the earphones will remain listenable even on ruder-sounding pop and rock material. While the top end was refined, it lacked some of the upper frequency air you might hear with more expensive ‘phones.
Image focus through the DTX 101 earbuds was acceptable, but I never heard the kind of imaging specificity or solidity, nor the wide, expansive soundstages that I heard through the similarly priced Shure SE-215s. Compared to the Shure SE-215s, the DTX 101 iEs sound thinner in the lower midrange, and lack some warmth and musicality. The Shures also offer more varied ear tip options, so that they enabled me to achieve a significantly better fit.
I was never a huge Beatles fan (I preferred the Rolling Stones) but I’ve been listening to The White Album and Abbey Road [both on Capitol] quite a bit lately. On “Sun King” the DTX 101 iEs were a lot like having a glaucoma test on your eardrums—gentle puffs of air moving your eardrum back and forth. Ringo’s high-hat and cymbals on “Mean Mr. Mustard” were way too prominent, giving the whole mix a tiss-boom quality. By the time Abbey Road got to the last kick drum hits on “Polythene Pam” any loose detritus left on my eardrums had been shaken off, with an action not unlike the sensor cleaner in my Pentax K-01 camera.
Last weekend I recorded the final concert in the Boulder Philharmonic’s 2011-2012 season. Through the DTX 101 iEs the Brahms Academic Orchestra sounded pretty good until the first forte around 2:30 into the piece. Then, the double basses’ sound became so untidy that it began to obscure the midrange. To their credit, the DTX 101 iEs made the massed strings sound very nice, giving them a just the right amount of sheen and presence.
With earphones, the fit can be everything. The better the earphones fit, the better they will sound. How much you like the Beyerdynamic DTX 101 iEs will depend on how well they fit you. With the three supplied eartips I was never able to get and keep an optimal fit unless I sat still at my desktop. But when properly seated, the DTX 101 iE earbuds deliver powerful midbass, an articulate midrange, and smooth upper frequency response.
Consider this earphone if:
Look further if: