Headphone Reviews

Raw frequency response plots with the standard cable show ruler flat response form 10Hz to about 400Hz. To my ear bass below 150Hz needs some boost in order to have proper weight. A rising response is desirable above 500Hz, but in this case it rises too fast and peaks too early at 1.7kHz. The lack of a 3kHz peak and the trough between 2kHz and 8kHz is substantially below target and gives the earphones a veiled sound, lacking presence and vocal overtones. Response 8kHz and above is near target and helps to regain a bit of treble sparkle.

30Hz square wave has good shape with a nice linear waveform top staying way above zero for its full length. This coupled with the extraordinarily low distortion figures in the bass evidence the very well controlled and textured, though slightly low in level, bass heard in listening.

30Hz square wave shows a fairly wide and slow initial leading edge. THis is likely due to the reduced treble response 2-8kHz. Impulse response, on the other hand, shows the polarity inverted, a fairly small initial transient relative to subsequent ringing, and some some modest high frequency ringing at about 10kHz. I really thought this would surface an audible problem, but with both cable I thought the treble resolution was quite good.

THD+noise plots is absolutely stellar. I didn't even think the noise floor on my measurement system would allow plots this low. This is a spectacularly linear, low distortion plot.

Impedance plot shows a very flat 27 Ohms; typical and expected from a PM headphone.

Isolation plot show that this is indeed an open headphone with a very typical amount of isolation.

Needing only 18mVrms to achieve 90dBspl at the ear drum, the iSine 20 will achieve fairly loud levels on portable devices.

Frequency Response with Cipher Lightning Cable

Raw frequency response plot with Cipher Lightning cable shows a significant amount of correction from passive wired response. I would call this a very good match with the Harman target response. I think the rise toward the 3kHz peak is a little too agressive, however, making vocals sound a bit too forward.