RHA CL750

The first thing that strikes me is the unusually long, transparent and twisted-down connection cable with a length of almost 1.50 metres. It is heavily encased, making it robust and less prone to typical knots. The other workmanship is exemplary, as the earphones, plugs and centre piece are all made of stainless steel. This not only looks classy but, according to the manufacturer, also leads to lower distortion in the earphones due to the explicitly high density and low resonance of the material, even at high volumes. At the same time, the attractive in-ear pieces should prove to be durable, even though the connection cable is unfortunately not interchangeable. The transformer used is the in-house CL Dynamic ultra-wideband​ transducer with a ring-shaped magnet and a 9 μ membrane, which, again according to the manufacturer, is characterised by its particularly wide frequency range and is suitable for high-resolution audio material.

Device Controls

The CL750 is a pure headphone for audiophile music enjoyment. As a no frills item, extras such as functions for volume control or making calls have been left out of the design.

The wearing comfort is thanks to a large selection of 12 pairs of fittings made of different materials (silicone, comply foam, etc.). The cable is guided over the auricle and thereby stabilised in the seat and relieved of strain. The noise isolation is average.

With an impedance of 150 Ohms, the CL750 is quite quiet on typical smartphones. However, RHA Audio also explicitly recommends using the headphones with dedicated headphone amplifiers or with mobile playback devices that provide adequate performance. In the test,​ I used the in-house Dacamp L1 in combination with an iPhone 8.

Sound Quality

On a suitable player, the CL750 rewards you with balanced sound matching and a combination of intimacy and openness that you would typically not achieve with a pure smartphone. In the central frequency ranges, the listener is provided with high detail resolution and sharp demarcation of the instruments involved so that they can hear deep into the mix.

The lower frequency range of the CL750 is traceable down to the low bass. I don’t notice any disturbing overemphasis either there, or in the rest of the bass foundation. On the contrary, it sounds contoured, full of pressure and with comprehensible tonality and dynamics. Even at high levels, the handset still works well in terms of size.

As far as altitude is concerned, the CL750 is transparent and rich in detail. At the same time, these properties have a positive effect on the depiction of percussive signals, the speech intelligibility of voices, and also on stereo imaging and the definition of a room. However, the CL750 has a slight overemphasis in the high frequencies that is not to my liking. As a rule, this leads to a gain in openness. For high-volume productions or percussion instruments such as a hi-hat, the CL750 shoots slightly faster than the target.