beyerdynamic DT 1770 Pro
Open or shut case?
beyerdynamic A 20Having granted a 2017 Sound+Image Award to Beyerdynamic’s DT 1990 Pro headphones, our affection for them is already clear. But a year or so prior to their introduction, the company had already released the DT 1770 Pro, a very similar design, but with closed headshells rather than the semi-open design of the award-winners. Would we like to compare the two models side by side?, asked Beyerdynamic’s new distributor in Australia, Synchronised Technology (aka Syntec).
DT 1990 ProYes indeed we would — the 1770 builds upon a classic design, and the interesting contrast between similar closed and open designs turned out to be a task made still more pleasurable by their inclusion of a neat little headphone amp with which we could drive them, Beyerdynamic’s own A 20 (pictured above), which retails in Australia for $999.
An interesting side effect of ever pricier consumer headphones is that professional headphones, which used to be rather more expensive, now aren’t; see also the Fostex on-ears this issue. We often like the balance of such models — pro headphones are unlikely to fake up the bass or provide some superficially pleasing EQ, given they’re for longterm studio use, for mixing and mastering, so accuracy is a key goal. We don’t mind a subtle bass lift on headphones, but on the whole, accuracy is, as in all things hi-fi, a worthy goal.
The drivers in both headphones use the company’s latest iteration of ‘Tesla’ driver technology, a neodymium magnet mounted as a ring encircling the coil, rather than the usual arrangement where the magnet sits at the centre. This allows an effectively larger magnet to deliver more powerful drive, along with lower losses in flux, which the company says can be used to deliver either more power and impact, or a higher level of detail, depending on how the headphone is engineered. 
The award-winning DT 1990 Pros first, then — as with all the company’s professional studio models the DT 1990 Pros are still “handcrafted in Germany”, and listed by beyerdynamic under Professional / Studio, yet perfectly suited to use by consumers at home. They’re open, and with 250-ohm impedance not so suited to mobile use unless you’re adding a decent portable headphone amp. They come with a large solid case, two sets of earpads, and two cables — one straight and five metres long, one coiled and three metres, both wildly over-wrapped by some Sellotape maniac loose in the beyerdynamic packing plant. These connect to the left earphone with a locking mini-XLR with a small button to unlock — quick but sturdy, perfect for studio use. The inclusions with the DT 1770 Pro are identical. 
The DT 1990 Pros open up a mix beautifully, with the airy sense of space that a closed headphone can (almost) never achieve. They’re highly revealing,  showing up the hot reverb effect on the right-channel piano string slides during the opening of The Doors’ L.A. Woman, or the sense of the hall when Keith Jarrett stomps his foot during his Köln concert recording. While the 45mm drivers deliver all of this sparkle up top — to 40kHz, according to the spec — they also manage a rapid and rich bass, achieving the full swelling bassline of Bowie’s Blackstar while still snapping those bizarre beats cleanly. They’re a delight across genres, and deliver a great sound for this price.
DT 1770 ProSwitching directly to the other model does the DT 1770 Pros a disservice, as the comparison highlights their closed nature dramatically. Take a long break before judging them on their own merits.
With the A 20 headphone amp behind them they delivered a powerful driving sound, perhaps a more accurate if less exuberant version of the truth, keeping a tight focus on individual elements. So if those Doors piano strings didn’t have quite the openness to their acoustic, there was no lack of ting to the ride cymbal, and the bass (by Presley’s bass player Jerry Scheff) was solid as a rock, full but sharp-edged. They roared through our usual test tracks, delivering the delicacy and resolving power required for kd lang’s The Air That I Breathe, the bass again full, the right-channel brushes delightfully tactile, her vocal just a fraction light and recessed — there seemed a small dip in response around middle C.
Leonard Cohen’s wideband vocal, on the other hand, was enormous on Going Home, almost too well underpinned on the O2 recording of Tower of Song. Classical music was handled with accuracy and dynamic lift, though here our preference was for the ambience and openness of the DT 1990s. Still, several of our listeners, and notably those with studio experience, were quite firm in their preference for the contained accuracy of the closed model.
We did try them directly into a mobile device, and they performed well enough, but with less sense of power a-plenty in reserve, and certainly less available level than a noisy commute might require.
In the home, then, for sheer pleasure, we’d take the DT 1990 Pro. But the closed model is another fine performer, and if you’re unable to spill sound willy-nilly, in a shared space or an office where you can keep a headphone amp, or if you need a good flat analytic musical tool, the DT 1770 Pro may be your go-to. Not just for the pros, then! — and separately prepared for your particular penchant.