Stax SR-009Description - Released by Stax recently (mid-2011), this is a full-size open electrostatic headphone, which incorporates a numerous changes from previous models including a new driver. Pink Noise - Extraordinarily even! Only slight and broad emphasis at upper-mid/low-treble ("chu"). Bass Texture - Other than being a little less hefty than I'd like (just a little), the extension was very, very good, and the texture was simply breathtaking. Felt like I heard the spit on the lips of the tuba player. Spectacularly clear. Bass Slam - Holy moly! These hit amazingly hard. Yes, the lowest two octaves are a bit shelved down, but my goodness they rock!
Click on graphs image to download .pdf for closer inspection.
Frequency response again shows the step at 50Hz, but this time smaller than on the 007. The slight rise to1kHz indicated a some upper mid-range presence, and aside from some wiggling (which is unavoidable), descends on what I would consider an ideal path from 1kHz to 20kHz. Also, please note the absence of any spike at 10kHz. This is rare. Looking at this treble response it's hard to know where the significant overshoot of the 300Hz square wave is coming from. My guess is ... speed? What do I care, all I know is that they have the best treble I've heard to date.
The THD+noise is picture perfect; the best I've measured, I think. Not surprised one bit however, as these are also spectacularly clean sounding cans. 100dB line below the 90dB line indicates excellent power handling.















