Casti Hi-Fi Sennheiser HD 550

Lots of mainstream audio products give you “bathtub” sound. They call it that because the frequency response curve is shaped like a bathtub. We like a nice soak as much as the next person, but with bathtub sound you’re drowning in bass and treble, vocals are weak, and certain frequencies resonate too loudly.

The HD 550 is the opposite — no gaps, peaks, or loofahs here. That means instruments don’t get “lost in the mix”. You can hear everything, and clearly. Deep sub bass reproduces frequencies you feel more than hear. Treble extends far beyond human hearing. Then there’s “soundstage”. Basically, high-end headphones make it feel like each sound is coming from a specific location. Not just left, right, or center, but also near and far, in front or behind you. Your ears do this 3D thing in real life, too. And with the right headphones, it works with recordings, games, and soundtracks.

Many modern headphones rely on electronics to achieve the desired sound. The HD 550, however, will have none of this: you get a direct analog signal path from source to ear. That means pure, unadulterated sound without additional noise or artifacts. This did put our engineers on the spot though: it meant the headphones had to be acoustically flawless.

They started with our excellent 150-ohm transducer inside the proven HD 500 chassis. We manufacture the transducer ourselves in Ireland, by the way, so you get outstanding quality and perfect channel matching. To create that 3D sound and wide soundstage, the transducers angle back towards the ears, mimicking real-life hearing. The dust cover is acoustically transparent. Even the ear cushion materials were selected for their acoustic properties. And a strategic bit of foam ensures smooth treble integration and controlled bass. The result is a neutral balance even our most demanding fans will appreciate. Open and airy, but never harsh, the HD 550 headphones are smooth enough to be anyone’s daily driver.

The HD 550 design is heavily influenced by feedback from people like you. And you said, “make it light, make it comfy, and make it sound great.” So we revised the headband, using high-quality synthetic leather and softer foam. With such a low total weight, less clamping force was required. Which in turn allowed us to use soft, comfy earpads with plush velour. You get a fit that’s stable but so unobtrusive that even long sessions are no problem. Work, play games, or listen for as long as you like — without pinching, pressure, charging, or pairing.

How can headphones from the days of the first “hip shake thang” still be going strong? Simple — German engineering and quality materials. And those haven’t changed. From the mechanics to the steel covers, our headphones are designed to withstand daily use or give collectors something to take out of a cabinet and dust every month for decades. You can get replacement parts like earpads for these headphones and many other Sennheiser products now — and years from now. And of course, all the accessories from our HD 500 range are compatible with your new HD 550 headphones.