Massdrop x HIFIMAN HE4XX Measurements and Quick Impressions https://www.massdrop.com/buy/massdrop-x-hifiman-he4xx-planar-magnetic-headphones Focus-A pads included! Very nice paint scheme. The photo above is well illuminated. The color is more sedate under typical lighting. Driver matching is quite good given the price. HIFIMAN remains a leader in driver matching. Holy cow, I just noticed the price. BUY THIS NOW! Massdrop x HE4XX Frequency Response This response was a bit unexpected... for the better. Compare to the HE400S measurement with Focus-A pads below: WHITE = HE400S with Focus-A pads (extra purchase) GREEN/RED = HE4XX The Massdrop version has been tuned for better bass extension and smoother more even response.