Thanks for the nice review, Amir!
A couple of things to note about the headphone:
1) There are new ear pads, with an Alcantara suede finish on the contact surface for improved comfort
2) NOIRE X includes our self-tensioning headband
3) Ear pads are enhanced to reduce potential for foam rolling, to extend usable pad life and enhance comfort
4) Numerous driver updates to improve consistency and performance
I thought it'd also be interesting to post some results from the 5128, with the diffuse-field and Harman EQ points used as a "Harman-style" reference. I will publish a larger post with analysis and commentary comparing the GRAS and 5128 later. The target curve in the 5128 measurement was derived by applying Harman Curve EQ points to the B&K diffuse field compensation curve. It is interesting to note just how close the NOIRE X fits this curve, and also where there are some real differences relative to the GRAS in measured results. There are interesting implications for this in setting EQ, which I'll discuss in the technical post.
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For a different view on THD I thought people might enjoy this, measured 85dB @1KHz on the GRAS. Note at 4KHz THD goes as low as 0.006%!
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Lastly, here's a beauty shot for those who like these...
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