iBasso SR2

This iBasso SR2 is the successor to the SR1, with only 500 units available. The manufacturer has equipped this model with a new combination of materials, improved drivers and optimised wearing comfort, and it is found in the price range between 500 and 600 euros.

In practice

The dynamic iBasso SR2 arrive in generous silver packaging. The appearance is both classic and classy. In addition to the headphones, the package includes a detachable 1.8m cable with a 3.5mm jack plug, a 6.5mm adapter, replacement pads with an alternative sound signature and a well-padded case suitable for everyday use, which ensures safe transportation of the headphones.

The round aluminium ear cups are made in one piece and bear an engraving of the manufacturer and model name on the inside. A honeycomb-like black metal grille protects the diaphragms and provides a nice contrast to the earpiece housings.

The ear pads are made of soft, slightly perforated faux leather that is extremely comfortable to the touch. The flexible spring steel headband is attached to the ear cups at two opposite outer points. These ensure a horizontal fit, while at the end of the headband, a swivel joint allows the ear cups to rotate. The connections are held in place by Allen screws, allowing for servicing replacement.

The wide padded headband is made of cowhide and can be adjusted in height comfortably but stably via the double guide on the side. This guide also prevents the headband from slipping on one side and bodes well for durable support. If you are the only person who will be using the headphones, you can fix the size using the Allen screws. The overall impression is one of stability, durability and a service-friendly design.

After putting the headphones on for the first time, I became aware of the interplay of the construction components. The generously designed headband allows the two ear-enclosing pads to rest softly without pressure. In combination with the wide, well-padded headband, this creates a really pleasant overall impression where you hardly feel the weight of the headphones. A good basis for several hours of music enjoyment.

The braided connection cable, a combination of copper and silver conductor, connects via two separate points on the ear cups with colour-coded 3.5 mm jack plugs. This proved to be very light as well as flexible and does not get knotted when in use. Due to the flexible connection, it was possible to use cables from third-party suppliers. This means that nothing is left to be desired.

Technology

In the SR2’s driver construction, iBasso uses a membrane made of bio-cellulose with a silicone surround. This lightweight and fast-pulsing diaphragm vibrates effortlessly due to the flexible connection and is acoustically isolated from the housing. This dynamic system is driven by a Tesla magnet which, due to its high density, has accurate control over the diaphragm vibration, which should enable detailed and precise spatial imaging. Likewise, this system provides resonant energy and a deep, controlled bass range.

The semi-open design is also beneficial, combining the best of open and closed designs. Airy sound and detailed three-dimensionality are paired with powerful reproduction across all frequency ranges while maintaining sufficient external damping.

The low impedance of 24 ohms combined with an output of 108 dB enables a wide range of applications. Even playback devices with low output power, such as smartphones, have no problem powering the SR2. But of course, these headphones will benefit from a dedicated amplifier system in order to play out to their full potential.

Sound of the iBasso SR2

A wireless MTX monitor with an integrated headphone amplifier served as our main playback device in this test. Other playback devices tested included a Cambridge Audio CXN V2, a CD player (NAD 512), a smartphone (Samsung Galaxy S7) and an iBasso DX 240 Reference DAP. Headphones from Stax, Focal (Spirit Pro, 32 ohms) and Sennheiser (HD 25 MKII, 70 ohms) were available for comparison.

The two included ear pads offer two different timbres. The finely perforated attachment sounds more balanced with a slight emphasis in the bass. The second set with larger perforations sound thinner with more treble emphasis. The following insights into the sound refer to the first set:

The iBasso SR2 deliver a natural sound. These headphones were able to reproduce deep bass in a relaxed and accurate manner. This applied to deep Techno bass drums as well as to heavy bass drums from the realm of Metal. The low frequencies were reproduced with punch depending on the recording and reached into the deep bass. In the tonally demanding midrange, the SR2 distinguished very distinctly in terms of colouration, intonation and dynamics of instruments and voices. Opera vocals, with the high dynamic differences typical of this genre, had enough stability not to get lost in the mix even at low volume. Upon arriving at forte fortissimo, the voice literally jumped out and was clearly defined directly in front of the listener. Rapid differences in dynamics were immediately conveyed. Metal riffs had the same precision and power in all their brutality. Nothing was glossed over; nothing was hidden. Rather, it was all presented directly with full body.

The high-frequency range was also astonishing: fast successive transient triplet figures, played on a cymbal, revealed the woody strike of the sticks, and this triggered a remarkable overtone spectrum. This precise and three-dimensional reproduction requires a fast-acting interplay of all components. And indeed, the result was a compelling soundscape. Ensembles, both small and large, were differentiated on the virtual stage. And the space surrounding the instruments was also impressively audible.