Want affordable open-back headphones? I tested Sennheiser's latest

Sennheiser’s 500-series of headphones has always been the company’s entry-level offering in the best wired headphones category, the place where aspiring audiophiles can supposedly get an idea of what true audio excellence is all about.

The Sennheiser HD 505 are the latest over-ear, open-backed design that the company hopes will prove to be the gateway into an enduring audio habit – and I've been testing them since announcement for this review, so let’s find out what the odds of becoming hooked are.

How much do Sennheiser's HD 505 cost?

The Sennheiser HD 505 have been on sale since February 10th 2025, and in the United Kingdom they’re priced at £229. In the United States they currently sell for $249. While in Australia they’re more like AU$449.

This puts them into direct competition with very credible, similarly specified alternatives from brands as well-regarded as Beyerdynamic and Grado – not to mention from Sennheiser itself…

Sennheiser HD 505: What's New?

The HD 505 may not have many features, but they have the sort of specification that’s intended to give more than just a taste of what makes Sennheiser such a venerable brand. ’Entry-level’ is all well and good, of course, but there are long-established standards to be upheld here.

Generally speaking, 500-series headphones have enjoyed wide frequency response and impressive dynamic range while erring towards the ‘insubstantial’ where low-frequency activity is concerned.

So Sennheiser has adapted a long-serving transducer for the HD 505 in an effort to deliver great bass weight and extension – while still maintaining their prized transparency, of course. The upshot is a pair of headphones with a claimed frequency response of 12Hz - 39kHz from those 38mm dynamic drivers, and an on-paper impedance of 120 ohms – which means they shouldn’t prove too tricky if connected directly to a laptop or a smartphone.

And given that this is a pair of headphones, that’s basically your lot where ‘features’ are concerned. The only other item of note is the cable – it locks into the left earcup using a 2.5mm connection, is 1.8m long, and is terminated at the business end by a 3.5mm jack with a 6.3mm adapter. Sennheiser is quick to point out that longer, and/or balanced, cable alternatives are widely available should you feel the need.

How good do the HD 505 sound?

Committed bass-heads, look away now. There’s more to life than audio ‘wallop’, of course – but those who value a bit of punch and body from their headphones are likely to find the HD 505 rather undernourished where the bottom end is concerned. The fact that the low-frequency activity these Sennheiser generate is swift, varied and controlled to the point that rhythms are expressed very confidently goes a long way towards making up for it, it’s true. But not all the way.

If you can get over this particular disappointment, though, you’ll find the HD 505 an accomplished and actually quite gregarious listen. They have a nice, natural tonality that allows the sound of a recording, rather than the sound of the headphones, to take centre stage, and they unify the frequency range in a similarly unforced manner.

The bottom end may need more flesh on its bones, but it nevertheless gets the prominence it deserves. The top-end shines benignly, while the midrange communicates with real purpose – and at every stage of the frequency range, detail levels are high and insight is impressive.

They have good dynamic headroom, so even the biggest shifts in volume or intensity during a recording are tracked faithfully, and more minor (but no less significant) harmonic variations are identified and put into context confidently too.

And where soundstaging is concerned, the HD 505 make their open-backed advantage really count. They are a spacious and expansive listen, and allow even the most complex recordings to stretch out – there’s more than enough elbow-room available to every element to fully express itself without being impacted on by any other.

The stage is well-defined and properly controlled, too, and entirely believable as a result. The space and silence in a recording can sometimes be as important as the actual occurrences, and these Sennheiser headphones make that point in fine style.

What's the HD 505 build like?

Like most reasonably affordable over-ear open-backed headphones, the Sennheiser HD 505 don’t stray far from the design template. Where the standard of build and finish is concerned, they’re well up to Sennheiser’s established levels, and while the materials from which they’re made don’t feel anything special, they’re entirely fit for purpose.

The earpads are of soft fabric over a quantity of memory foam, and the back of the earcups feature wire mesh and some discreet branding. The inside of the headband is gently padded, covered with synthetic leather, and conceals the nicely positive headband adjustment mechanism.

Sennheiser has paid a lot of attention to the clamping force the HD 505 exert, and it’s fair to say that they remain comfortable for a good long while – and, unlike some rival designs I could mention, the earpads don’t heat your ears all that quickly either. And with an all-in weight of just 237g, this is a manageable pair of headphones in every respect.

I probably don’t need to dwell on ‘usability’ too much. You’ll need a source of music with either a 3.5mm or 6.33 headphone socket, and you’ll need to plug the HD 505 into it. And then you’re up and running…

Sennheiser HD 505 review: Verdict

Even though it’s a fairly niche part of the market, you’re not short of choice where reasonably affordable, high-achieving open-backed over-ear headphones are concerned – but you most certainly have to make the Sennheiser HD 505 part of your shortlist.

In almost every respect, the HD 505 have the necessary sonic credentials – and where comfort is concerned, they’re among the very best around. With a little more low-end brawn they’d go further still.

Also consider

Beyerdynamic’s DT 900 Pro X are a very worthwhile alternative to the HD 505 – they have a slightly more studio-centric emphasis where overall sound is concerned, but they’re comfortable to wear and absolutely no kind of hardship to listen to.

And as long as you consider their looks ‘retro’ rather than ‘old-fashioned’, Grado’s excellent SR325x headphones are down to something very like HD 505 money now – and they are most certainly worth hearing.

Perhaps the most compelling alternative, though, is Sennheiser’s own HD 600 – they’re a step up in performance, and they’ve been around long enough for their price to dip down close to HD 505 money every now and then…