Today, Louis reviews the Sennheiser HD 550, a new set of 150Ω open-back dynamic driver headphones with a microphone-ready design. They are currently priced at $349.95.
Disclaimer: This sample was sent to me in exchange for my honest opinion. Headfonics is an independent website with no affiliate links or services. I thank Sennheiser for this opportunity.
Click here to learn more about the Sennheiser products we have previously reviewed on Headfonics.
Note that this feature follows our latest scoring guidelines, which you can read in more detail here.
When Sennheiser released the new HD 550 priced at $349.95, some sniped at the fact that Sennheiser released it too close to the debut of the HD 505.
However, I beg to differ due to the patterns of the 500 series and the way Sennheiser rolled out each series. The 500 series has become a vast labyrinth of models that most time have been launched in sets of threes.
For example, the HD 515, HD 555, and HD 595. Then Sennheiser released the HD 518, HD 558, and HD 598. Then, they released the HD 599, the HD 579, the HD 559, and a couple of other models.
Recently, the series produced the HD 560S, the HD 505, and today’s subject, which is the HD 550.
Being the most expensive model yet in the series, it has to produce the best-in-series sonics because, on the outside, it looks to be the most straightforward model offered to date, and nothing new is under the sun, as they say.
Features
The Sennheiser HD 550 hasn’t veered away from the original concept much at all, and it remains a recognizable offering, but it does veer on simplicity. The main attraction here is the open frame design mounted driver that can be seen best on the ear pad side of the oval cups.
The Sennheiser HD 550 uses a custom angle-mounted 38mm transducer designed and crafted in Sennheiser’s Tullamore, Ireland, audiophile facility. This 150Ω transducer is capable of producing a frequency spectrum of 6Hz to 39.5kHz and an SPL of 106.7 dB at 1mW.
The HD 550 is aimed at audiophiles, yes. However, there’s a lot of talk about this headphone being a good candidate for gaming as well, and in general, that is a true claim for most of Sennheiser’s headphones at any tier level, and it’s because of their refined soundstage. But I also feel they’re good for monitoring work as well.
The HD 550 is an oval cup, open-back headphone, but the rear grill looks as if breathability was not part of the design objective.
The balancing act to achieve here is to remain true to the open back concept, while managing to protect the driver, its optimum positioning, and the right acoustic impedance.
Design
The overall design in general is minimalistic this time around, but it’s my preference over ornate designs from the past. I could point at the beige PC, Noctua-themed HD 598, for example, but that’s ancient history now, and let’s look forward.
The Sennheiser name was only placed on the left side as a visual cue for the left channel alignment, with the right side completely black with braille marking below for visually impaired (or low-light) listening.
I do like the all-black color scheme Sennheiser used this time around. The only major color break in the black color theme is a silver ring around the cup that breaks things up, supplying just a touch of contrast and distinction to the all-black theme.
One thing I did note is that if you compare the HD 550 to previous models, the assembly components seemed heftier on past models, which could be a con. I’ve never had any issues with any of the previously mentioned models, and only time will tell if this model will follow suit.
Another thing, I can use the HD 599 as an example on this one. Being a high-tier model in the series, the HD 550 trim is minuscule this time around.
Previous models displayed nicer, deluxe trim, and they felt heftier construction-wise as well. Then again, weight loss is one of the obvious benefits, just hopefully it’s not a trade-off for longevity.
Comfort
It seems that Sennheiser attempted to lose a few grams here and there because the build is thinner than other models in the series, especially around the headband adjustment area.
The overall weight of the HD 550 is 237 grams, which makes it the lightest model within the HD 500 line, and a draw in weight with the HD 505.
I’ve never had comfort issues with Sennheiser headphones, this one included. Sennheiser managed to reduce the clamping force over the past HD500 series models to a point where you don’t feel the pad pressure as much.
The headband cushion has just the right amount to feel comfortable, but not lose enough that they feel like they can come off easily.
I would have preferred a V-shaped cutout like the HD 560S has on the top-center, which alleviates that center pressure point on top of the head.
I don’t know why Sennheiser didn’t keep that implementation going, which is a simple implementation; that is a benefit to the user and is a cheap fix.
Stock Pads
The oval-shaped pads remain, and they’re also a carryover from the HD 505. They’re a bit stiff, but being familiar with these pads, they will flatten over time before coming apart, which will bring the ear closer to the transducer and increase sonic intensity.
They’re easy to remove and replace, and if you’ve ever removed any of the HD 500 series pads, these will be familiar to you.
You have to pull them hard from the inside to unclip them, and to replace them, you press them in place. Pull firmly outward and upward simultaneously to remove them. Just be mindful of the driver.
On a side note. In my experience, aftermarket pads change the sonic characteristics of Sennheiser headphones, and if you ever need to replace these, try to replace them with original variants to retain the original sonic tuning.
These HD 550 stock pads are made from a velvet-like cloth with a fast-reacting, medium-stiffness foam. The ear pad border is thin, and this helps minimize pressure on the cheeks and jawline.
The pads are mounted on the now-common Sennheiser ring system, which hasn’t changed throughout the series.
Stock Cable
The stock cable seems to be identical to the one included with the HD 505. It’s a rubber-insulated black cable that seems to be OFC with a 3.5mm termination. Sennheiser includes a step-up screw-on converter from the 3.5mm connector to a 6.35mm variant.
The other end is equipped with a rather long 2.5mm twist-on plug that has some pros and cons. The pro aspect is that it’s a solid connector. The con aspect is that only that type of plug will be the only one that can fit on there, and that limits cable choices.
Being a headphone that is an excellent choice for gaming, this limits you to an external microphone, and you can’t use a V-MODA Boom Pro or a Meze Audio Boom microphone set. Perhaps Sennheiser can offer one in the future.
Sennheiser does offer an in-line mic option, part number 572281, but it does not come with a boom option.
Packaging & Accessories
The HD 550 comes with a minimal number of accessories. Sennheiser includes a black spandex drawstring bag, the cable with the adapter, and a small product instruction pamphlet.
I was highly unimpressed with the HD 505 packaging, but this time around, the HD 550 comes inside a properly laminated box and not just a plain brown box.
It shows effort on behalf of Sennheiser to get things right, but the inside is just as unimpressive as the previous HD 505 brown box experience.
The headphones are placed within a cardboard frame that keeps them from moving inside the packaging.
Sennheiser is not impressing me with fancy packaging, and just gives you the product. That is fine as long as the product gets home safely and the packaging is adequate for that purpose.
Sound Impressions
My testbed consists of several components, starting with the Rose Technics RT-5000, and the SMSL stack consisting of the SU-X and the SH-X. Those components and the iFi audio iDSD NEO 2 were also used.
The FiiO M11 Pro was used to supply a portability perspective, along with the ONIX Alpha XI1, and the FiiO KA17 running off my daily mobile device, which is a Motorola Edge.
Summary
I know some people don’t believe in break-in; My stance is that it applies to certain sets, and here’s one of them.
At first, the treble response was a bit shy and splashy, plus the bass response was also timid, until I ran them for just a few hours. Then I noticed improvements, even in the midrange.
The HD 550’s overall tonality is neutral and well-extended, with a balanced character, typical of Sennheiser cans. They shine with a vivid midrange and a well-proounced bottom-to-top representation.
One sonic area that was fixed on this model is the bass response, which seems more ample compared to other models in the HD 500 series.
The bass in this model is more in line with the rest of the frequency response, and it veers the HD 550 away from the bright and bass-light presentation of previous models.
Bass
Fortunately, the HD 550 produces bass that is free from some of the resonant anomalies that past HD500 series headphones were plagued with, and managed to keep things clean. Sennheiser has paid close attention to eliminating resonances in the bass area.
In the bass department, the Sennheiser HD 550 happens to be one of the most potent in the series. It remains what I consider to be flat, and Sennheiser’s measurements show that. Meaning that the usual dip is less pronounced on this set.
The HD 550 doesn’t take the gradual bass dip compared to the rest of the series and generates bass that, although I would have preferred a bit more punch and dynamism. Regardless of that, the bass does feel more satisfying compared to other HD 500 series headphones.
The bass response is ineffective below 28Hz. Above that, the bass response remains effective until the 55Hz mark. Above that, the bass is produced in full bloom and nicely transitions into the midrange region with no midbass peaks or bleed.
Midrange
Somehow, Sennheiser managed to bring forth the midrange and vocals, but kept them under control. The vocals do seem warm, especially female vocals. You could say that the midrange is a bit thick around the waist.
That thick characteristic gives the mids some body and but some might complain that it veers the vocals from sounding organic. I interpret it as added character and body, which keeps things interesting.
The Sennheiser frequency graph points at a significant 200Hz dip, which I am sure is not the source of warmth, but the source of a loss of presence in the lower midrange region. What this does is it makes vocals seem more relaxed and polite.
The HD 550 excels in the midrange area, just like most Sennheiser headphones. They offer an organic experience and clarity with a balanced, well-presented midrange profile with lots of detail, enough to do some critical listening.
Treble
It’s not that the Sennheiser HD 550 is a bright headphone, but the high frequencies, in general, are more forward, and perhaps, again, the uncovering of the driver, I bet, is the source of that characteristic.
The treble, although well accentuated, is non-fatiguing, and the HD 550 produces high frequencies that are harshness-free and well defined.
The HD 550 produces high frequencies that lack a bit of sparkle and shimmer but feel more in line with good vintage highs that are weighty and meaty, but they don’t hit the highest of notes.
The high frequencies remain solidly represented up to 14k; at that point, they take a hard dive.
Staging & Dynamics
For a headphone with a small transducer, the HD 550 surely produces a large, lifelike sonic panorama of sound that is large and immersive. These headphones sound larger than one would expect them to. But they are more productive at producing height over any other spatial element.
There’s a respectable amount of all the necessary elements of a soundstage, but sometimes things can get congregated, especially around the midrange section. Sidelines are produced with a well-defined placement and good high-frequency micro-placement.
Vocals and some instruments are well-centered and sound wide. Although sonically the HD 550 can get complex, one can also distinguish all the components in a recording with a high level of perceived placement when conglomeration does not occur.
Click on page 2 below for my recommended pairings and selected comparisons.
