Headphone Reviews

The Sound and Measurements
I can tell you that the world of headphone geeks is all abuzz with praise for the sonics of this spectacular little headphone.

I've been listening my way through a bunch of sealed headphones, both full-size and on-ear, preparing to do a buyers guide. I started with sealed headphones because, as a rule, they suck. All that trapped air inside the closed earcups, both between the headphone and ear and behind the driver, makes for a great opportunity for resonances and whatnot to muddle up the sound. Headphone makers really struggle to get sealed headphones to sound good. I simply don't get how Beyerdynamic managed to get such great audio performance from such small, sealed headphones.

Simply put, these are the best sounding supra-aural, sealed headphones I've heard. Tight and bottomless bass, well articulated highs without harshness, and a mid-range truthful to the tone of a human voice are all here. The problem is the bits don't integrate into a natural whole as well as the very best headphones. But they do it as well or better than any other small sealed can I've heard.

The DT 1350 does the highs quite well, though they do have a bit of a cupped sound in the low treble. To my ears, brush strokes on snare drums sounded dryer and almost papery; on my LCD-2 you could hear the natural sound of the skin. To hear these problems, however, I have to compare these cans to my reference headphones. Compared to virtually all other headphones of their type, their treble response is spectacular. Nicely detailed, without any harshness. Man! I wish there were more headphones I could say that about.

I'm going to mix the measurements in with some more sonic observations because they so strongly tell the tale with these cans.

The lower traces on the graph show the raw measurements of the headphone in five slightly different positions on the ear. The amplitude spread of these measurements in the lower frequencies is due to the changing seal on the ear when repositioned. The spread of these data with the DT 1350 is fairly small relative to other cans of this type, and indicates good performance of the earpads sealing on the ears.

The upper traces are the spatially averaged and HRTF compensated frequency response of the left (blue) and right (red) channels. The flat extension of the bass from 100Hz to 10Hz is simply amazing. I've never seen anything even close to this in an earpad headphone, and only a few full-sized cans achieve it. The bass on the DT 1350 is bottomless, this headphone does the low notes spectacularly.

The frequency response curves from 100Hz to 1000Hz is slightly bumpy, but still quite good for a headphone of this type. Above 1000Hz, the frequency response gently rolls off until about 7kHz where it spikes to peak at 9kHz followed by some peaks and valleys. The dip at 7kHz is a somewhat normal result, but slightly excessive with these headphones.

As I listen to these cans for coloration, I sense them as quite neutral, though they don't sound nearly as open or deep imaging as better full-sized headphones. One comment I read on a Head-Fi thread that kept ringing in my ears was this one:

"With the 1350, it requires readjustment every time, even if it's the only headphone I've been using. I might think it's because it's hard to squeeze all the frequency ranges into a small on-the-ear headphone, so maybe there is a hole in the response that is jarring when the ear first hears it." --- Beagle

I think that dip at 7kHz may be somewhat responsible, and I do think that the bumps and wiggles below 3kHz may indeed show the remaining artifacts of "squeez[ing] all the frequency ranges" into the headphones after the engineers did their best tweaking them. One thing missing for me in these cans is "coherence," which is essentially the time or phase alignment of the various frequencies. When sound is coherent, it tends to sound deep and deliver the whole of the music intimately. It seems to me that the DT 1350 suffers from a lack of coherence somewhat, possibly due to the small size of the enclosure and all the correcting done to compensate for it. Again, in my experience, poor imaging and coherence are very common in small, sealed cans, and it may mean that you have to psycho-acoustically reacquire the aural image encoded in the somewhat unnatural signal every time you put them on.

On the best 30Hz square waves, the top and bottom are straight lines. On most headphones they sag inwards. On the DT 1350 they hump up a little --- it's quite an unusual response. But notice how they stay nicely above zero over the entire length of the top; this indicates a strong, tight, properly phased bass response. And boy do these headphones have it. It may have a little color in it --- I did perceive these cans as a tad uneven in listening --- but man, the power in the bass is right where it needs to be. No accentuated, bloated, one-note bass here, just deep and clear. Fabulous!

Most headphones overshoot and ring a bit on the 300Hz square wave. Like the 30Hz square wave previously, the DT 1350 300Hz square wave is rather odd, but also a rather good result. The square wave has good shape with a flat top and relatively clean edges. The little squiggle at the leading edge is odd, but fairly closely matches the ideal. The odd, but good, square wave results lead me to believe the Beyerdynamic engineers really sweated some blood getting things to be as accurate as possible. My ears and these measurements tell me they did very well indeed.

Most headphones show rising curves in the lows due, I believe, to the performance of the headphone seal, and the driver's ability to compress air linearly. The DT 1350 shows very little Low end distortion. Also, the 100dB SPL curve remains below the 90dB SPL curve in its entirety, showing that bass impact and power handling are very good with these headphones, and distortion is mostly noise. There are very few headphones beside in-ear monitors that achieve this.

Summary
I think I'll throw in a couple of quotes from others on Head-Fi:

"The DT 1350 buries and puts the nail on the coffin on all of my former headphones." - Dyn4m1c95
"These are truly the perfect portables." - Dyn4m1c95
"They're like the headphone equivalent of a great small loudspeaker." - Beagle

And my comment in the thread:

"Spoiler: They're the best supra-aural, sealed headphones I've heard. Maybe I'll just post that." - Tyll Hertsens

Indeed, it's very hard not to just post: Buy the DT 1350, they are full of win in every possible way. I more than strongly recommend them; I think if you're interested in headphones you should do everything within the law to get your hands on a pair to permanently add to your collection. These are the new standard for portable earpad headphones, and I suspect they'll hold that chair for a long, long time. They have my highest possible recommendation.

Resources after the video!

Resources
Beyerdynamic's web page, pdf brochure, and Facebook story for the DT 1350.
Measurement datasheet for the DT 1350 and T50p.
The very informative Head-Fi thread on the DT 1350.
How to take them apart for re-wireing post.

All quotes in story used by permission.