beyerdynamic DT 1990 PRO MkII & DT 1770 PRO MkII

The DT 1990 PRO MkII and DT 1770 PRO MkII are essentially open‑ and closed‑back versions of the same design.

The new MkII editions of beyerdynamic’s flagship headphones are outwardly identical to the previous versions. Internally, however, it’s a very different story!

As befits a manufacturer celebrating their centenary, beyerdynamic products tend to stand the test of time. The company’s very first headphones, the DT 48s, were in continuous production from 1937 to 2012, while the still‑current M 160 and M 130 ribbon microphones date back to the 1950s, and the iconic, rectangular DT 100s have been a recording‑studio staple since their introduction in 1965. Any new model that enters the beyerdynamic line‑up has a lot to live up to — and recent headphone launches have done a pretty good job of it.

At the top end of the market, headphone development at beyerdynamic has focused on two proprietary driver technologies called STELLAR and TESLA. In a moving‑coil loudspeaker or headphone driver, a coil of wire is attached to the back of the diaphragm, with a permanent magnet positioned inside it. When the amplified audio signal is passed through the wire, electromagnetic induction does its thing and the diaphragm is pushed and pulled at a frequency determined by the signal.

In the original version of the TESLA driver, the usual geometry was reversed, and instead of locating the magnet inside the wire coil, beyerdynamic used a ring‑shaped magnet that sat outside the coil. This generated a particularly powerful magnetic flux density, with concomitant benefits in terms of sensitivity and low distortion. The TESLA driver was first used in high‑end headphones for the consumer hi‑fi market, but soon found its way into two studio products: the closed‑back DT 1770 PRO and the open‑back DT 1990 PRO. These were introduced in 2016, and have proved very popular despite — or, perhaps, because of? — the fact that they were never reviewed in this magazine.

To celebrate their anniversary, beyerdynamic have introduced upgraded or special edition versions of quite a few products, and their flagship studio headphones are no exception. Both the DT 1770 PRO and DT 1990 PRO are now at MkII, with an updated version of the TESLA driver that is said to improve performance still further.

The new driver, dubbed the TESLA.45, actually reverts to a more conventional structure with the magnet inside the voice coil, but still achieves a flux density in excess of 1T. It also incorporates many of the improvements made in the STELLAR.45 driver used in the DT 700 and 900 PRO X models, while one of the biggest steps forward has been the development of a new diaphragm geometry. In the new TESLA.45 driver, the voice coil is not wound directly onto the back of the diaphragm, but onto a lightweight collar that protrudes outwards. This design ensures that the voice coil remains entirely within the magnet gap even at relatively high excursion levels, delivering greater linearity and lower distortion.

An exploded view of one side of the DT 1990 PRO MkII, showing the new TESLA.45 driver.

Open & Shut Case

The 1770 and 1990 are, respectively, closed‑back and open‑back versions of a design that is otherwise identical. They are manufactured at beyerdynamic’s Heilbronn headquarters in central Germany, and their construction is pleasingly businesslike and serious‑looking, with a ‘none more black’ aesthetic that seems fitting for a professional studio tool. The two models ship in the same lightweight, zip‑up, semi‑rigid case, which is also entirely black and has no identifying features, so if you’re lucky enough to own both models you’ll open the wrong case approximately 50 percent of the time. It would benefit from having a handle, but most importantly, it offers a decent level of protection whilst being much lighter than typical hard‑shell cases.

Within the case, a pouch houses the detachable cables, offering the traditional choice of straight or curly. The former is 3m long and the latter will stretch to 5m. These attach to the base of the left earcup using a mini‑XLR, and to your audio device through the equally time‑honoured mini‑jack with optional 6.5mm screw‑on adaptor. As well as the headphones themselves, both models also come with a second set of earpads. The stock earpads are velour‑covered: in the case of the DT 1990 PRO MkII, they are designated the Producing version, and introduce a small bass boost. The second set supplied with the 1770 have an imitation leather cover and offer greater isolation from external sound, while the alternative Mixing & Mastering earpads for the 1990 are also velour and are intended to flatten the response. (The headband cushion is also replaceable.)

However, swapping earpads isn’t something I’d want to attempt on a regular basis. On paper, or in PDF manual, the process is simple: you snag the elastic band that lines the back of the earpad on a notch in the rim of the earcup, and twist through 360 degrees. If that works first time, it takes a few seconds. But if it doesn’t, the band becomes increasingly stretched and non‑compliant, and it quickly gets frustrating. Having swapped the first one with no fuss at all, it took me nearly an hour to do my second earpad. It doesn’t help that the two sets of earpads for the 1990 are indistinguishable once attached to the earcups.

The physical...