If you want an objective measure for how good a pair of headphones is, look at how long it’s been on sale. Sennheiser’s HD 650 has gone unchanged for 13 years, having once been the pinnacle of the German company’s lineup. Priced at its usual $500, this set of open-back cans remains a benchmark setter that others have to compare themselves against, but today it’s getting a makeover that drops the cost down to a frankly ridiculous $199.99. Massdrop, the crowd-shopping website that collaborates with headphone manufacturers to do special limited editions of popular headphones, has worked with Sennheiser and is today offering a special HD 6XX variant at that lower price.

The Sennheiser HD 6XX is identical to the HD 650 in its sound signature, construction materials, and Ireland-based manufacturing. It only differs in having a new "midnight blue" color scheme that swaps out the 650’s grays for an almost-black shade of indigo blue around the ear cups and the headband. The 6XX also makes a couple of convenience improvements: the cable has been shortened to 1.5m / 5ft and it now terminates in a 3.5mm connector instead of the 650’s 6.35mm jack. Otherwise, though, this is the exact same HD 650 that my colleague Chris Plante fell in love with over a decade of happy listening.

There are only 5,000 units available for the present "drop," which begins right now and is unlikely to last a terribly long time. US deliveries are expected to be completed by December 25th, though no such promises are made for international customers.

You won’t find another pair of $200 headphones coming close to this level of quality anytime soon

In any case, the advice for these headphones at this price is a no-brainer: buy them if and while you can. You won’t find any other $200 headphones coming close to this level of quality anytime soon.

I’ve been listening to a set of the HD 6XX for a few days ahead of their launch today, and they do indeed exhibit the sweet tonal characteristics of the Sennheiser HD 650. There’s nothing about these headphones that is offensive: they have pleasing, but not overwhelming bass, they cover the full range of frequencies with faithful accuracy, and they seem incapable of reproducing harsh treble. The HD 650 / 6XX provide a relaxed listen that will remain enjoyable for hours on end. They have a bit of a bass bump to them, which is especially satisfying when watching movies or playing games, adding that extra bit of low rumble to action sequences and explosions.

These cans have remained unaltered for so long because their balance is so good. They don’t offend, they don’t fatigue, and they walk the fine line of pleasing both audio purists and casual listeners.

Another major plus for the HD 650 / 6XX is their fit and comfort. Their big oblong ear cups wrap securely and snugly around the ear and simply feel cozy. Their clamping force is relatively strong, and they will leave an imprint on your hairstyle after you’ve worn them, but those are unproblematic things where comfort is concerned. I find these headphones supremely comfortable, with their physical lightness and fit being a fine match to their polite, friendly sound signature.

If there are downsides to the HD 650, they are small and easy to pick up on a spec sheet. First is that they’re open back, so you’ll be wanting to use them in an environment where you won’t aggravate people nearby (and external noise won’t spoil your enjoyment of your music). I wouldn’t call them perfectly transparent, however, like something from the Grado range, as the 650s still manage to isolate exterior sound to some degree, even with their wide-open metal mesh covers. The other potential issue is that, at an impedance of 300 Ohm, these headphones require a powerful amplifier to drive them to their fullest. You can get away with plugging them into a phone, but that won’t bring you anywhere near maxing out their potential. A dedicated amplifier, at least a portable one like the Oppo HA-2 is a required purchase along with the HD 650. But then, at the HD 6XX’s $199 price, you get exactly enough off the regular 650 price to purchase an HA-2SE, so it all works out nicely in the end!