Ollo Audio S4X Reference Headphone Review
Ollo Audio is a relatively new headphone company, based in beautiful Slovenia. They are not famous, at least not yet; but, they already managed to create some buzz around their two headphones, a closed and an open back. Both designs promise a natural response, while the open headphone, the S4X, is marketed as reference headphone.
My main complaints about most headphones are that they are either too bass-heavy, too harsh in the highs, or too expensive. Therefore, as soon as I heard about Ollo's ambitions to produce a high-quality, reasonably priced open-back headphone with flat frequency response, I knew I had to try it.
From the edge of the Alps
The S4X comes in a rather minimal box, both in size and appearance. Upon opening, one is treated with a canny slogan: "Save the planet, you can't listen to music in space". Along with the headphone, here is a small black paper pouch that protects the removable cable, and a pleather carrying bag. The presentation is simple and imparts a handcrafted feeling.
There is also a black envelope that encompasses various documents. Besides a manual, there is a printed frequency response measurement and a hand-signed certificate of authenticity. Neat touches. Lastly, a caution notice alerts us not to press hard the headphones on flat surfaces, to avoid distorting the membrane of the speakers.
Manufacturing and comfort
The headphone itself looks quite handsome and feels very well made. Quality materials have been used throughout; wooden earcups, stainless steel grills and headband, along with memory foam earcups. The weight of the S4X is substantial, but the self-adjusting strap in combination with the plush feeling of the earpads, made of a hybrid of velvet and pleather, make them very comfortable to wear for hours.
Although these are over-ear headphones, the earpads are what I consider as medium-sized. They fit my ears snuggly and are deep enough, but there is not much space around. If you have larger ears than average, you will feel them getting squeezed.
Another nice touch is the removable cable that terminates on a dual 2.5mm TRS for the cups, and 3.5mm TRS that connects to the source. A 3,5mm to 6.3mm adapter is included to accommodate any setup. The cable is 2 meters in length, of good quality and light, so it doesn't weight down the headphone. It has cloth braiding until the Y split for extra protection; then divides into two red rubberized cables that connect into each cup to minimize microphonics.
The cups don't have L/R markings; they become left or right speakers depending on which cable-end you connect to them. This interchangeability makes servicing very easy, but since the lettering on the cable is tiny, it gets a bit annoying to look for it every time. A coloured connector would have been preferable, but that's only a small annoyance and is easy to fix.
Reference(s)
When I received the Ollo's about two months ago, I let them burn-in for about 100 hours and have been using them since almost daily. I've been directly comparing them with the Focal Clear Pro, various Beyerdyanamics, and AKG's, along with PSI and Focal studio monitors.
A fantastic headphone for me doesn't have a sound of its own; it gives me an honest presentation and ensures a seamless transition between it and my monitors, regardless if I use headphones for mixing, mastering, or pure enjoyment.
Reality check
I'm happy to report that Ollo's claim for a flat headphone is not just marketing talk.
The S4X has a full response and shows remarkable depth in its presentation; the instruments feel real. The sound is natural with fast transient response. Also, there seems to be an absence of earcup resonances.
Other than the slightly elevated low-end, no frequency stands out. Bass is solid-sounding and has an excellent extension. Mids are delicate and detailed, and highs are smooth and non-fatiguing. The sound is true to the source. Ollo's have a similar to my monitors' response; much more than my other headphones - other than the Focal Clear Pro.
The soundstage is average with an intimate presentation; the Ollo's put the listener on the stage with the musicians. I also get the impression that the S4X are a bit like a semi-open headphone instead of a fully open design. Detail retrieval is above average, but not in the realm of the Focal Clear or Beyer T1.2.
Listening to properly captured classical guitar recordings, the sound is immersive with every detail presented accurately. If there are problems in the recording or performance, the headphone will show it without shouting at you. This makes it both an excellent tool in the studio and an enjoyable listening experience at home.
In use
With an impedance of 32 Ohm, the headphone is easily driven even by mobile devices. It does sound considerably better with my RME ADI-2 Pro FS or the RME Babyface Pro FS.
Their small size makes them also, great for location work; although Germany is on lockdown since November and I didn't have the chance to test them in that application.
A modular approach
Aside from the sound, what's cool about Ollo is the philosophy behind the designs. They allow their customers to service the headphones themselves, if the necessity arises, as every part is easily replaceable at home. To sweeten the deal, even more, they offer a five-year warranty, and the ability to upgrade the headphones with new drivers and other parts.
In other words, Ollo promises a customer experience opposite to that of almost every other headphone (and not only) company.
Complaints
My only gripe with the S4X is the excessive rining of the stainless steel headband. It only occurs when you put them on or touch it for some reason, so in actual use, it is not a problem, It does give a negative impression on an overall very well thought out headphone.
Honestly, I got used to it and it doesn't bother me anymore, but I wish that Ollo would find a replacement or a way to decouple the headband from the driver.
I would also like to see a hardshell case option, as it would offer better protection when travelling.
Conclusions
Ollo's marketing is quite aggressive and bold, but it is probably necessary at this stage as they need to get noticed. Unlike some of the most popular brands which have flooded the market with numerous models, Ollo seems to listen to their customers and refine their designs.
I don't know if the S4X is a brutally honest headphone, like Ollo claims; but it is an accurate and detailed headphone, without being overly analytic.
The refined and natural sound, coupled with excellent craftsmanship, and the fact that there is no middle man to inflate the prices, make it one of the best headphones in their price range and well above.
