Review: Sennheiser HD 4.40 BT

Sennheiser HD 4.40 BT - 01

As an advocate of quality cables, robust amplification and a controlled listening environment, bluetooth headphones had never made it on my radar. But then my house informally adopted quiet hours from 9pm onward and it became less about having a pristine listening experience and more about simply listening to my favorite music with as little fuss as possible.

The true catalyst for wireless audio was getting a shiny new headphone jack-less iPhone. Doing things around the house with a cord dangling to my phone was annoying enough, let alone getting a crappy dongle involved. 

I’m certainly not alone in my newly-developed predicament, and the marketplace has reacted accordingly. At one point in time, bluetooth options were fraught with compromises, lacking in the sound-quality-department or being prohibitively expensive (or both). But the past year or so has brought about many new contenders in the wireless audio space, one being the masterful audio juggernaut Sennheiser. 

Sennheiser’s newest wireless offerings are the HD 4.40 BT bluetooth and HD 4.50 BTNC noise-cancelling bluetooth headphones. While they have had a number of (more premium) wireless options in the marketplace for some time now, the new options clock in at less than half the price, $149 and $199 respectively. This article is looking at the 4.40 BT headphones; I’ll address the 4.50 BTNC headphones in another article. 

So, in a world of $350 Beats Wireless and Bose QC35 II headphones, what can $149 get you?

Solid construction. NFC chip built in to the left ear cup.

Styling & Features

The HD 4.40 is an indisputably attractive headphone, in a utilitarian sense. Simple and strong lines, free of flashy designs, gaudy colors and weak attempts at looking “on trend.” It’s a decidedly masculine look that will stand the test of time. 

Construction is fantastic; 100% quality plastics and pleather, and I mean that as a positive. Many plastics feel cheap, but Sennheiser’s material selection is impeccable, with each component feeling solid and resilient. The ear pads are notably puffy and plush, with a hidden bed of memory foam that hugs your head ever-so snugly. 

All controls are consolidated on the bottom rim of the right ear cup. There’s a simple push button (power/bluetooth pairing), a recoiling slider (previous, next, play/pause), and a rocker button (volume up and down), along with a micro USB port for charging and a 3.5mm headphone jack for passive, hardwired listening. 

While the buttons all feel unique enough for blind identification, I find the controls a bit cumbersome. None of them have a very satisfying click and the slider/push button is finicky, feeling entirely too loose for confident use, as it essentially moves around like a pushable joystick.

Portability is decent, as the ear cups curl into the headband, forming a headphone pretzel. While the “footprint” may be small, they obviously don’t get thinner. I would prefer more of the “lay-flat” configuration that Bose utilizes, as that form more easily slips into a backpack or briefcase.

Sennheiser decided to cut costs by making the “case” a useless little square of pleather. I can’t stress enough how pointless this thing is. While it will protect from surface scratches, I can’t imagine anyone will actually use it. If they had just not included a “case,” I wouldn’t have thought twice. But the fact that they did include it and yet made it so poorly is what raises questions. 

Battery life is fantastic at a claimed 25 hours (I can attest to that). If you have a current smartphone, the 4.40 will treat you well with 4.0 bluetooth, AptX codec (with a compatible phone), NFC, and so-so phone call capability. 

Sound Quality

Sound quality does not disappoint. While it’s not the flavor for the most discerning of critical listeners, Sennheiser has paired a fun, engaging experience with a smooth frequency response. No one “section” of the sound signature stands out as overpowering or missing. Soundstage and imaging, essentially how they recreate a “3D” soundscape around your head, is generally good, considering the closed-back design and price point. 

Dissecting the sound signature a bit more, the bass is definitely exaggerated, and while that will be pleasing to most people, it’s worth noting that is does bleed into the lower-midrange quite a bit, leaving the overall presentation feeling a little “heavy.” Midrange is remarkably smooth and blends seamlessly into the upper-mid, lower-treble region. Unfortunately, I find the 3.5-5 kHz treble range far too recessed, giving everything a slight “distance” from the listener. 

Put it all together and you have a smooth, warm presentation, with punchy dynamics and a never-fatiguing upper register. While it’s not a particularly neutral or even “accurate” sound signature, the 4.40 is pleasant to listen to. I think that many people that hear these will consider them the best headphones they’ve ever heard—they sound that good, in a general-consumer kind of way (versus the snooty audiophile). 

Two minor disappointments in the sound department: the noise floor (hiss from the onboard amplifier, mostly noticeable when music isn’t playing) is pretty loud and if you like your music loud, you’ll likely be disappointed, as max volume is surprisingly conservative. 

HD 4.40 BT have a sleek, understated look but are plagued with ear-smashing discomfort.


And here comes the caveat: the 4.40 is, for me, utterly uncomfortable. Sennheiser, in an apparent attempt to make their headphones more portable and less dorky-looking, has slowly-but-surely been shrinking all of their ear cups. Seriously, check out every review of all of their non-audiophile headphones over the past 5 years and you’ll find that one common complaint. 

The 4.40 is considered a “circumaural” headphone, meaning the ear pads go around (circum) your ears (aural). On my average-sized ears, the front lip of the ear pad sits in front, while the back “scoops” and cradles the back of my ear’s auricle, effectively bending my ear to fit inside the ear cup. On top of that, the headphones have an overabundance of clamping force on the head, only emphasizing the ear smooshing, even after dozens of hours of wear (clamping force usually diminishes with extended wear as the headband stretches out). 

Furthermore, the closed-back design, coupled with dense memory foam and shallow cups create for a rather hot environment after a pretty short amount time. 

But as much as I can complain about my own personal discomfort, I can’t speak for everyone. No two heads are shaped the same and perhaps my ears are bigger than I realize. 


For my purposes—casually listening to music late-evening while relaxing around the house—Sennheiser has built a terrific pair of headphones. Attractive, sturdy, fun sound and no fatigue. If you’re in need of headphones for public commute, these would be a great companion with great looks, punchy dynamics and solid passive noise isolation. And in such a small, expensive segment of the personal audio space, $149 is a real bargain.

If you’re in need of a decent pair of wireless headphones, the Sennheiser HD 4.40 BT get an enthusiastic thumbs up from me— provided you have small ears.