Sennheiser HD 505 Review – Metal Machine Music, Part II
Here at the blog we are unapologetic acolytes of Sennheiser, whose venerable, 20-year old HD 650 is the epitome of an affordable, genuinely audiophile over-ear. Its new, $250 HD 505 certainly looks tempting, with solid (but not premium) build, cushy earpads, and refreshingly light (237 g w/o cable) weight.
They’re quite comfortable, too, despite considerable clamping force (which does serve to keep them stable and increase isolation). Unexpectedly tough to drive—my modest Audirect Atom 3 dongle needed to be at 80% to get suitable thrust but still sounded thin—I did most of my testing with my JDS 02 head amp, which thickened the notes but imparts no coloration.
Superficially, the HD 505 mimics the sound signature of the HD 650—midforward and well-extended in the treble region and rolled-off in lower frequencies, albeit considerably brighter, with much a leaner note presentation. Soundstage is wide and high-ceilinged on the HD 505 and imaging is accurate; there’s a lot of space between performers, which allows you to discern little nuances and microdetails like handclaps and breaths.
However, where the tonality of the HD 650 is supremely accurate and live-sounding, the HD 505’s tonality is just a bit “off”. High end does present a lot of information, but sounds harsh at the extremes, especially at higher volumes.[1]
Mids are highly resolving and forward but seem artificially enhanced and unnatural; male voices in particular can sound shouty. As with the HD 650, subbass isn’t deep, but where the low end on the HD 650 is very even and tight, the HD 505 presents an odd dip in the midbass region, which forces your ears to focus on the lower mids and gives these an audible incoherence.
The HD 505 do pair well with acoustic fare, where the lack of low frequency quantity is less critical; something like Gillian Welch or Richard Thompson has an open, clean (if somewhat clinical) presentation. Harder stuff (say, the new Lifehouse edition of Who’s Next”) sounds bassless and sorta hollow, as if the presence range had been EQ’d all the way down.
I compared the HD 505 to a couple of $200ish cans I have on the rack. The (wired) Senn Momentum share the fairly thin tone of its labelmate but have more low end, better coherence and are the better-sounding phone.
The Philips Fidelio X2 are warmer, smoother and fuller-sounding; they trail the HD 505 in soundstage width and are less extended and detailed at the high end, but likewise sound more lifelike and engaging.
Stepping up a bit to the Grado SR225 yields a much deeper, authoritative bass, sweeter richer mids and an airier, more cohesive presentation; the HD 505 does have more high end sparkle and marginally better instrument separation, but again sounds dialed-down and “digital” compared to the Grado.
The 505 have their considerable virtues, but ultimately fall into the good technicalities/flawed tonality camp. I take no pleasure in criticizing these, but sometimes it be that way. For around the same price you can get a used HD 650 or a new HD 650 variant like the HD 6xx or HD 600, any of which will give a truer representation of the source. I am, surprisingly and unhappily, compelled to withhold my thumbs-up for the 505.
Disclaimer: I received this sample from Sennheiser USA for which I am sincerely grateful. We fervently hope they won’t be mad at us and will continue to send us stuff in the future.
[1] Out of the box, the high end was so shrill as to be unlistenable; an hour or so of burn-in largely mitigated this effect.

Specifications Sennheiser HD 505
Article Number (SKU): 700453 Weight w/o cable: 237g Cable: 1.80 m cable with 3.5 mm jack plug, detachable, left side Ear Coupling: Around Ear (Circumaural) Ear pad material: Synthetic velour Frequency response: 12 Hz – 38.5 kHz Nominal impedance: 20 Ω Package dimensions: 237x191x96mm Package weight: 569.16 g Sound pressure level (SPL): 107.9 dB (1 kHz / 1 Vrms) THD, total harmonic distortion: <0.2 % (1 kHz / 90 dB SPL) Transducer principle (headphones): dynamic, open-back What’s in the box: HD 505 Copper Edition open-back headphones, 1.80 m cable with 3.5 mm plug, 3.5 to 6.35 mm screw-on jack adapter, Drawstring bag |
A Note from Sennheiser (2025-03-14)
A note about naming: Like many audio brands, we use an alphanumeric system for many of our products. With an 80 year anniversary on our heels, we have no doubt amassed an enormous catalog of product names….some of the rules we have established along the way have been bent as the markets and products evolve. As of this writing, we’re simplifying the names so that it becomes a bit easier to classify our products. While not perfect (and not entirely retroactive) our next few releases are a great demonstration of the new naming methodology.
The first letters classify the headphone at the widest part of the funnel: “HD” stands for Headphone, Dynamic, as it always has. IE is an In-Ear (dynamic), HE is Headphone Electrostatic, etc. This remains unchanged.
The next number (in this instance, “5”) places the headphone in a performance series: HD 500, 600, or 800..again, unchanged.
The numbers after that is where we are going to tighten things up.
x20 will be reserved for closed-back models (example: HD 820, HD 620S)
x50 and x00 will lean towards neutral tuning (example: HD 800S)
x60 will lean towards a warmer tuning (example: HD 660S2)
xx5 will, in most cases, indicate a retailer limited release in your market (example: HD 505)
Our back catalog is, naturally, full of exceptions and nuances, so feel free to ask any questions if you have them, and thanks for coming along with us on the journey!
Disclaimer
Our generic standard disclaimer.

