Headphone Reviews

Raw frequency response plots show that the Spirit One reliably seals on the head and delivers consistent performance as position changes around the ear. Compensated frequency plots show a headphone with a gentle warm tilt to 1kHz and a mildly uneven response, which is quite common with sealed headphones of this type. The slight wiggle at 90Hz is likely due to ear cushion resonance and is not easily heard. Bass response is slightly elevated---about the right amount, it seems to me---and very well extended. Coupled with fairly good 30Hz square wave shape and lack of distortion in the low frequencies I'd expect these to have very tight, slamming bass, which was heard in listening tests.

The frequency response drops off significantly after 1kHz indicating some lowering of presence region response. I'd like to see the response remain flat to about 2kHz before dropping off. A moderate peak at 10kHz is apparent, this can be troubling accompanied by a significantly ragged 300Hz square wave leading edge, but in this case I heard some dryness or grain in the treble, but nothing terribly offensive.

300Hz square wave leading edge has a slight overshoot and some minor ringing, which can also be seen in the impulse response. But I would say these are fairly good results relative to other headphones in this category.

THD+noise is a bit elevated at 7kHz, but remains at 1% or less otherwise, which is fairly good. The 100dB THD+noise plot remains comfortable below the 90dB plot indicating a headphone with very good power handling ability.

Impedance and phase plot show a 35 Ohm headphone with little in the way of reactive influence as frequency changes. Coupled with 35mVrms efficiency, and 18dB broad band attenuation, these should perform very well as a mobile headphone attached to smart-phones and tablets.