Ollo Audio S4R

Ollo Audio S4R package

The Ollo Audio S4R is a recording headphone with a refreshingly different pedigree. While many other devices originate from China, this one comes from the tranquil town of Šempas in the EU country of Slovenia

In addition to the headphones, a carrying pouch and a certificate of authenticity, a 2-metre silicone-sheathed braided Y-cable made of oxygen-free copper are included. This is to keep the distortion of the audio signal low. It is attached to the ear cups via 2.5mm mini-jack plugs. On the other end, it has a 3.5mm mini jack plug, which is suitable for smartphones etc. An adapter to a 6.3mm jack is also included. All plugs are gold-plated for corrosion protection.

If you buy your pair of headphones directly from Ollo Audio’s online shop, you will receive a five-year guarantee on the technical core headphones, excluding the connection cable and pads. If you need even more reassurance about your purchase from this still relatively unknown manufacturer, then you can even try out the device for up to 30 days from the date of delivery and return it if you don’t like it.

Ollo Audio S4R – design and construction

The Ollo Audio S4R are dynamic headphones with a closed-back design aimed at recording and content production applications. The 360-degree rotatable ear cups are made of American walnut, and they have a sandwich construction so that they each consist of two independent parts. This is to stop the material from resonating and thus offers protection against phase cancellations.

The 2cm deep, interchangeable ear pads on the ear cups leave a 55mm diameter space for each ear. The ear pads are made of soft velour and durable elastic polyurethane leather, as used in marine upholstery. Inside, acoustic foam provides not only a certain amount of insulation but also a good fit on the head. The stainless steel headband is also covered with marine leather. Its black powder coating provides a timeless look. Overall, the design is indicative of the final handmade production that the buyer receives with these headphones.

Ollo Audio S4R – technology and values

The Ollo Audio S4R employs transducers with 50mm diaphragms made of ultra-thin plastic film, dynamically driven by powerful neodymium magnets. Their dual-layer wound coil is said to reduce coil impedance at high frequencies, improving treble reproduction. The manufacturer matches those left-right pairs that best fit each other within production tolerances.

The headphones reproduce audio over frequencies from 20 Hz to 20 kHz. This corresponds to the typical human hearing range. In practice, their distortion-free sound pressure reaches up to 97.34 dBSPL, which puts them in the lower average range compared to other headphones. Nevertheless, the average impedance of 31.1 ohms allows them to play loud even when using headphone outputs with low voltage. This makes them suitable for working with laptops, tablets and smartphones.

Ollo Audio S4R – handling

The Ollo Audio S4R’s otherwise black cable is red from the splice and ends on a black plug and a red plug for the left and right sides. This is both practical and stylish. The connections for the cable are slightly offset to the front of the ear cups, so the cable can be easily routed in front. However, there is no locking device to prevent the cable from being pulled.

The width of the headband on the S4R is chosen to match that of artificial heads used in test engineering. For an optimal fit, the synthetic leather band automatically adjusts to the head size. What’s more, the wide headband distributes the weight so comfortably that these headphones can be worn without strain, even for long periods. The ears do not sweat under the pads. The contact pressure is just strong enough to keep the headphones’ weight of just over 380 grams on your head. Therefore, it is better if you don’t make jerky movements with them on. According to Ollo Audio, the ear cups as well as the band and braces of the headband can be replaced using conventional tools. All in all, we are dealing with a high level of wearing comfort and consistently simple and practical handling.

Ollo Audio S4R – sound

Ollo Audio promised us a particularly clear studio-quality sound with the S4R. And indeed, the first thing that struck me was its clearly imaged treble. In the super-high range, these headphones were not quite as open as some competing models. Nevertheless, the signal resolution was subjectively very precise. The mid-range offered high speech intelligibility and a lot of detail. Even the sound of rock and metal guitars got a smooth finish. There was no noticeable susceptibility to lisping in this frequency range. Only when listening to music productions that are already slightly problematic was there occasionally a small peak in the sibilance of s-sounds. The bass range of the S4R was punchy and featured an almost perfectly tuned sub-bass.

The entire sound image had a natural, neutral basic orientation with a warm note, without lacking richness of detail and depth. For me, the Ollo Audio S4R contributed decisively to its positive image by delivering good dynamics that were far removed from the compressed sound that some other closed headphones deliver. The transient response was well-balanced between sufficiently concise and soft. And in terms of distortion-free reproduction, quite high volumes were possible. However, the proportion of treble and upper mid-range sounds gradually became more pronounced as the volume increased.

The headphone design and frequency response are well-balanced. I could not detect any disturbing resonances. The attenuation of external noise was high, and the acoustic isolation of the S4R from the outside was very good. This makes them ideal as recording headphones for miked recordings and as a monitoring tool for content creation where crosstalk needs to be kept to a minimum, such as live podcasts.