Headphone Reviews

Sound Quality
Now that I've spent a little time complaining about the problems of a strongly sealed headphone, I'll do an about face and mention what seems to be their characteristic strengths: dynamics. Maybe it's the tight pressure coupling of the driver into the ear that does it, but holy mackerel, what ever it is, the MH40 hits hard. Unfortunately I can't find it again, but a quote from one of the Head-Fi threads on the MH40 keeps repeating itself inside my head, "It's as if this headphone emphasizes everything. I know that would just bring it back to flat, but that's what the MH40 sounds like." A very apt description. In listening tests I compared the MH40 with the Sennheiser Momentum, Shure SRH1540, Focal Spirit Pro, and NAD VISO HP50. Only the HP50 came close to delivering the slam of the MH40, the rest seemed almost thin in comparison.

Overall, I'd characterize the MH40 frequency response in general as slightly laid back from neutral, and a somewhat uneven. Bass response is strong, very tight and punchy, but not overemphasized. What modest emphasis there is, is fairly well in line with the Harman target response and I hear it as generally neutral—though the emphasis continues to 300Hz where the target response would have it stop around 150Hz, possibly making these cans ever so slightly thick sounding. But it's hard to perceive it that way as the bass is so tight and nicely in level otherwise.

Writing about the midrange is tough because I hear it as rather unremarkable. Between the slightly emphasized bass bleeding into mids down low, and a bit of excess as the mids rise some before transitioning into the treble, I end up hearing the midrange as rather lackluster and just a bit shouty. I didn't get the same sense of organic wholeness to the voice that I did in a number of other cans, which delivered a more liquid and even sense of naturally layered harmonics through the mids.

Though the upper-mids are strong, response falls off into a mid-treble notch (centered at about 6kHz). A lot of headphones have a notch like this (Focal Spirit Pro, Momentum) that generally produces an artificial sounding treble; I often hear it as "papery" sounding. A lot depends on how much and in what way the upper treble responds. To my ear I find the MH40 a bit rough, but fairly quick in response. I heard very little of what I would characterize as harsh or steely response. While the unevenness does tend to blur the fine layering in instrument separation and depth, a nice snappy transient response gives a good course sense of overall space. So, while the treble is a bit artificial, it's not abrasive or off-putting, and does porvide some sense of space.

The thing that keeps coming back to me with the Master & Dynamic MH40 is how punchy and dynamic they sound. You can look at the measurements and tell they're going to be a bit uneven and unrefined sounding. But what you can't quite see in the measurements is how those flaws end up giving the headphone its character. In some headphones that erroneous character might be "muffled" or "lean", and it's not particularly appealing. But in this case, the mix of flaws ends up producing the potentially attractive characteristic of dynamism.

A Little Postscript
When I first heard the MH40 and found the very tight seal somewhat bothersome, I called Master & Dynamic and talked with their headphone engineer. He was aware of this character but felt it delivered benefits. I asked if he had tried a pad with a little controlled leak, and he hadn't.

In preparing for this review, I noticed the new limited edition Proenza Schouler models...and their perforated leather pads. So, I contacted the engineer again and asked if these cans pads had different acoustic tuning. He said because of his earlier conversation with me they did give pads with some leakage a try, but found they didn't like the tuning. So, while the Proenza Schouler cans have perforated pads, the foam underneath is sealed.

He did send me some prototype pads that were more open so I could measure them and have a listen. While the leaky pads did reduce the problems of the strong seal, they also reduced the bass level to pretty much measured as dead flat. I felt the cans with the leaky pads needed a little more bass, but worse, lost some of their impactful magic. I prefer the headphones in stock form with the sealed pad. Such is the nature of compromise, I guess.

Summary
The Master & Dynamic MH40 has the look, feel, and price tag of a headphone ready to deliver a terrific experience...and deliver it does. The all leather and metal construction is top-notch, and accessorization is good—though I would have preferred a hard-sided carry case.

Overall, ergonomics and comfort are good, but somewhat marred by the cable connector coming directly out of the bottom of the ear piece, which will then rub against shirt and coat collars and make noise in the headphones. This problem is exaggerated by the very tight seal with the MH40, which allows chewing, footfall, and other mechanical noises to become louder to the listener than with headphones using a more leaky seal in their design. Also, changes in seal due to hair or glasses arms will more significantly effect response than with leaky designs.

The mildly troublesome nature of the pad seal problem, however, is significantly outweighed by the sonic gains, it seems to me. The MH40 manages to strike a unique balance between being amazingly dynamic sounding and yet laid back and gentle on the ears at the same time. No, these cans aren't particularly even or refined sounding, but somehow their imperfections add up to remarkably fun and energetic listening.

I'm not going to put the Mater & Dynamic on the "Wall of Fame" as I feel they're inferior to the HP50, Spirit Pro, and SRH1540 in various ways. But in narrow category of dynamism they pretty easily best those headphones, and because they don't have any glaring or fatal flaws I'll happily recommend them to folks looking for a terrifically dynamic headphone. Forget about what row your ticket says, get a pair of MH40s and sit right up on stage with the band!

Video

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Resources
Master & Dynamic home page and MH40 product page.
Head-Fi reviews here and discussion thread here.
Changstar thread and Ultrabike measurements here.