Sennheiser Momentum

Disclaimer: This is another loan provided by my good friend, Danganronpa. I shall return his generosity with an accurate analysis! 

Dr. Axel Grell of Sennheiser holding a pair of Momentum
from http://www.aes.org/conferences/51/invited_speakers.cfm

Introduced in the late 2012, Sennheiser Momentum is a closed-air/closed back portable circumaural headphone featuring a real leather ear pad & sleek design. At the CES 2013, Dr. Axel Grell, the designer of Momentum, has mentioned:

"The sound is still sennheiser-like and the style meets the sound quality."

As Sennheiser have always been very truthful to their reference sound, which is a downward sloped diffuse-field response, it can be assumed that Momentum is accurately calibrated to match the target as well.

 

PRO: Surprisingly, the headphone's frequency response accurately follows the ITU tolerance limit from 300 Hz to 17 kHz. The sharp deep-null centered at 4.5 kHz is most likely due to inter-driver reflection, and it is compensated with a time-delay: IOW the null is nothing to worry about. As far as the fit goes, since earpads secure the position of the pinna tightly, there isn't much chance for a placement-induced response deviation to be involved.

CON: A high distortion in the sub-bass range.

ON SECOND THOUGHT #1: There are two acoustic vents on top of Momentum's housing, but it turns out they do not alter the sound significantly.

ON SECOND THOUGHT #2: Here's a little peer-review. Although many headphone analysis websites have measured this headphone, none of their data actually matches with one another. What can possibly cause such a huge deviation?? Fortunately, my data (compensated by using B&K's calibration chart) matches that of Headphoneinfo quite well up to 10 kHz.

ON SECOND THOUGHT #3: If the peaks around 10 kHz can be somehow nullified, Momentum shall become very close to Dr.Olive's reference target.