By aspect — in detail
Mids
Strong consensus · 12 srcThe near-unanimous high point, and the reason the HD 505 gets recommended at all. Sources across every tier call the midrange forward, full and natural, with vocals singled out repeatedly as the standout; several rate it the best voicing in the HD 500 line. The one shared caveat is that the upper midrange is pushed, which buys clarity and detail but makes it a less forgiving midrange on rough recordings.
“This is arguably the HD505’s greatest strength.”
Sai, unheardlab
“the midrange is excellent here but right on the edge of my tolerance for upper midrange elevation”
Griffin Silver (listener), Headphones.com
Measured
Griffin measured his unit on a B&K 5128 against an HD 600 overlay, and puts the difference down to a little extra energy near 2 kHz alongside less lower-midrange bloom than the 6 series; SoundGuys read the ~3 kHz ear-gain hump as roughly 4 dB louder than it should be against their studio curve, and suggest small cuts at 2.4 and 2.9 kHz to tame it.
Tonality
Moderate · 12 srcBroadly read as balanced and neutral-leaning, and everyone agrees it is fuller and less clinical than the HD 560S. What sources do not agree on is which side of neutral it lands: Sennheiser markets it as 'analytical', and reviewers variously describe the result as analytical and slightly cold, pleasantly neutral, or actively warm. The disagreement is really about the presence region and the top end (below), not about the overall tilt.
“It does have a more analytical sound to it, which means it can sound cold or sterile if you’re not expecting it.”
HiFi-Dawson, HiFi Oasis
“what I hear could be described as more of a warmth to the Sennheiser HD 505’s sound – and it’s a very appealing warmth”
Trusted Reviews
Measured
Rated 120 Ω nominal / 107.9 dB at 1 kHz per 1 Vrms, 12 Hz–38.5 kHz, THD <0.2% at 90 dB. unheardlab measures the impedance nearer 137 Ω at 1 kHz with a conventional moving-coil curve, and notes that a high-output-impedance source will shift the response around the impedance peak — worth knowing if the tonality you hear does not match the reviews.
Agreement on the character, a real split on whether there is enough of it. Sources consistently describe a clean, tightly controlled low end that extends well for an open back — Griffin Silver hears the reach of an HD 650 without its lower-midrange bloom — and just as consistently note it does not slam. Where they part company is the verdict on that: some call it deep and satisfying, others call it thin and short on weight, and two reviewers recommend a shelf of a few dB below 60 Hz.
“The HD 505s reproduce impressively deep bass without sounding muddy or uncontained.”
Christian de Looper, PCMag
“a definite lack of substance and weight to the bottom end, a bony and flimsy quality”
Simon Lucas, TechRadar
Measured
SoundGuys measure a sub-bass rolloff against their preference curve and give it a pass as typical for the type; unheardlab's leakage graph shows the usual open-back bass loss when the seal breaks (glasses arms measurably cost you low end), and flags bass distortion at 94 dB as notably higher than the HD 560S — the added bass quantity pushing closer to what the driver will do.
The defining HD 505 argument. Everyone measures the same thing — a lifted presence and lower-treble region with some unevenness above it — and reviewers report flatly opposite experiences: over-bright, dry and faintly sibilant for one camp, smooth and fatigue-free for the other. The tell is that the two reviewers who measured it both blame earcup placement: wear the cups a few millimetres further forward and the top end lifts audibly. A narrow cut somewhere between 4 and 8 kHz reconciles most listeners.
Measured
Three rigs, one story with different emphases: Griffin hears a low-treble resonance around 5.5 kHz on his head and no 7–7.5 kHz dip or 10–11 kHz peak to balance it; unheardlab measures unevenness between 7 and 9 kHz and hears peaks near 7 kHz and 8.3 kHz on a sine sweep; SoundGuys read the ~3 kHz ear-gain hump as about 4 dB too loud against their studio curve and prescribe a −3.3 dB cut at 4.6 kHz. unheardlab's positional-variation graph shows the response moving substantially with placement on the rig.
⚠ vs. listeners — The camps are not disputing the lift — they are hearing different amounts of it. Griffin wears the cups low and forward with his ear tucked under the pad and explicitly warns that readers who centre their ear in the pad will hear it brighter than he does; unheardlab's positional graph measures exactly that instability. So 'over-bright' and 'perfectly smooth' can both be true reports of the same headphone on different heads, and repositioning the cups is worth trying before reaching for EQ.
Where it splits
Bright and dry — an energetic presence region that tips into scratchiness or sibilance.54%
“the HD505 exhibits slightly more pronounced sibilance compared to the HD560S, especially in 7–9kHz region”
Sai, unheardlab
Smooth and fatigue-free — clear and open without undue brightness or sibilance.46%
“The treble response is not overly sharp and tends to have a fatigue-free character.”
Louis, Headfonics
Soundstage
Contested · 12 srcSources split, and the split runs along the line between mainstream reviewers and the measurement-minded ones. The hi-fi and consumer press consistently describe an airy, expansive, wide-open presentation and treat it as the headphone's calling card next to closed-backs; the two most technical listeners hear something wider than an HD 6XX but firmly inside the head, and SoundGuys' MDAQS immersiveness score is the one weak number in their set. Both camps agree the angled drivers help placement more than they help width.
Measured
SoundGuys' MDAQS scores from HEAD acoustics read Timbre 4.8 and Distortion 4.2 but Immersiveness 2.8 — the objective counterweight to the 'expansive' impressions, and the one metric where the HD 505 does not do well for an open back.
Where it splits
Expansive and airy — the open-back payoff, and a big step up from closed-backs.60%
“Instruments flourish in a soundstage that is pleasingly airy and spacious”
Kashfia Kabir, What Hi-Fi?
Wide but in-head — roomier than an HD 6XX, not genuinely out-of-head or immersive.40%
“more spacious than the HD6XX but still not exceptional in today’s mid-fi market”
Sai, unheardlab
Imaging
Strong consensus · 8 srcA genuine strength and the least contested of the spatial qualities. Reviewers describe placement as precise and predictable, with a well-defined centre image and easy-to-follow directional cues — the reason the HD 505 keeps getting recommended for gaming and film despite the argument over how big its stage is.
“I think the thing people will most like about HD 505 is its sense of imaging precision and overall placement”
Griffin Silver (listener), Headphones.com
“Imaging and separation are quite good, with a well-defined center image that adds a touch of holographic feel.”
Sai, unheardlab
Measured
unheardlab reports good channel matching on their unit and links it to imaging precision and the clarity of spatial cues; Sennheiser's angled-driver design is aimed at exactly this.
Rated good for the money without being a headline act. The upper-midrange emphasis buys real clarity and texture through the mids, and most reviewers call detail levels high; a minority finds instruments comparatively soft-focus next to the vocals, and no one places it near genuinely resolving open-backs. Several also note it responds well to being fed a better source.
“Detail levels are high at every point of the frequency range”
Simon Lucas, TechRadar
“instruments don’t sound as detailed or defined, the Sennheisers aren’t the most insightful in that respect”
Trusted Reviews
Middle of the road, and the aspect that most divides the mainstream press from the measurement crowd. Reviewers who liked it describe a lively, uncompressed listen that swings from quiet to loud without strain; those less taken with it hear smeared transients and a shortage of weight, and Trusted Reviews specifically found games and films drained of energy by the restrained low end.
“They’re a fairly dynamic listen, too, able to put a lot of distance between the most contemplative and the most intense passages of a recording without sounding in any way stressed.”
Simon Lucas, TechRadar
“HD 505’s dynamics are okay, if a bit too focused on smack in the midrange”
Griffin Silver (listener), Headphones.com
A headline strength with one specific, repeatable caveat. At 237 g it is lighter than almost anything it competes with, the clamp is noticeably gentler than the HD 560S, and the roomy velour pads vent well — most reviewers simply forget they are wearing it. The exception is the headband pad: it is a single unslotted piece, and three independent reviewers report a pressure point on the crown after roughly half an hour. Whether it affects you is a function of head shape.
“The Sennheiser HD 505 are, and this will sound odd, an almost unremarkably comfortable pair of headphones.”
Trusted Reviews
“the headband padding is flat-out insufficient for me when it comes to long-term comfort”
Griffin Silver (listener), Headphones.com
Measured
237 g without cable (Sennheiser, and confirmed by every reviewer who weighed it) against the 280 g HD 560S; unheardlab rates the clamp 'light-medium' and comfort 9/10; the adjustment slider has eighteen clicks per side, and both pads and headband pad are user-replaceable parts.
Durable rather than luxurious, and nobody pretends otherwise. It is essentially all polymer with a metal grille, and reviewers who have lived with the 500-series chassis vouch for its longevity while calling the finish plasticky. The concrete gripe is the proprietary 2.5 mm twist-lock earcup connector, which rules out ordinary third-party cables; one reviewer also worries the wrapped synthetic-leather headband will be hard to replace when it starts to peel.
“mostly plastic, yet well-built and robust. It doesn’t scream luxury, but it’s solid and durable.”
Sai, unheardlab
“Proprietary port locks mean you can’t just buy any old cable on Amazon to replace the stock one.”
Christian Thomas, SoundGuys
Isolation
Strong consensus · 6 srcOpen-back by design: it blocks essentially nothing and everyone nearby hears what you are playing. The one nuance reviewers add is that the grille is less open than the HD 600 series, so it leaks a little less than the average open-back — which still does not make it an office or commuting headphone.
“You’re still going to be able to hear pretty much everything around you, so be prepared for that.”
Christian Thomas, SoundGuys
“Just because the HD 505 aren’t the leakiest open-backed headphone around, that doesn’t mean they should be worn in the office.”
Simon Lucas, TechRadar
The other real argument, and it is entirely about Sennheiser's own catalogue rather than the competition. One camp treats the HD 505 as an easy recommendation and a fine first audiophile headphone; the other points out that the HD 560S sells for roughly half, that the $199 HD 6XX is widely held to be the better headphone, and that a discounted HD 600 often lands at similar money. Street pricing has moved a long way since launch, which moves the verdict with it — the most critical reviewer added later that at 30–40% off he recommends it warmly.
Where it splits
Strong value — a well-judged, comfortable open-back and an easy first audiophile buy.56%
“Likeable and comfortable headphones that offer a smooth, open and engaging sound – these Sennheisers are easy to recommend”
Kashfia Kabir, What Hi-Fi?
Undercut by Sennheiser's own line — the HD 560S, HD 6XX and discounted HD 600 make it a hard sell at list.44%
“The problem is that Sennheiser’s own HD560S and HD6XX exist at significantly lower prices while offering similar performance.”
Sai, unheardlab
