People can't hear below 20hz (normally) but we can perceive the physical vibrations.
Perhaps the brain can simply interpret the vibrations (when loud enough to feel) into an audible tone - the human brain is quite fascinating and it wouldn't surprise me if this was the case.
Listen guys, I said 10 Hz for me and it is real. The 4 Hz thing was Sony's spec for the MDR-1R which didn't make it anywhere near the Momentum when I tried it. So how many of you tried the Momentums with the app that I mentioned to see how low you can hear? Now I don't hear anything. Let's go folks, I'm sure some of you can do it.
I don't find them THAT big to be fair, It's certainly not as big as the Mad dog or some other headphones. I think they look quite good the colour is nice and it goes well with the velour pads. I wear mine out, I wore my Mad dog out a few times and I looked like a right dork so they came off lol DT770 doesn't have recessed mids at all. This website really throws the words recessed Mids around a lot. The dt770 are not ruler flat by any means they have a slight boost in bass but overall it's quite a balanced headphone. I really love my DT770! I prefer them to most of my headphones.
I have the DT 770 80 ohm as well but I use my COP outside. The COP is prettier than the 770, has a 1.5m cable compared to 3m, isolates better, is driven easier by my iPhone, is bassier and the highs aren't as strident. Yeah, everybody loves mentioning recessed mids whenever there's talk about a Beyer. For such a prolific thing it has evaded me.
I've done some test. I don't have a proper mic so I used some headphones as a mic. I generated chirp from 15 to 1000Hz and played back from Xonar DG and amplified though PMA500, but in source direct mode. The headphones that I used as mic are rather poor, so I wouldn't believe these results too much.
Here we're looking at since wave at around 31Hz played by three headphones:
One thing that you may have noticed are very visible harmonics. When you play deep bass sound you would hear its harmonics rather than bass it-self.
I can't explain on these graphs why does the RHA30 have more harmonics than Momentum, while when you listen to them RHA30 definitely sounds deeper. Could be this poor headphones that I used as mic. Also could be that they are open, and I can't just test them the way I did (sticking one to another).
The more I look at these graphs the more I'm confused...
Harmonics are lower in amplitude than the fundamental frequency and when you sweep frequencies this becomes apparent. I have a background in recording studios and worked with Electronic Music Synths back in the day when they were analog computers. I am very familiar with musical notes and tones. I can hear down to 10 Hz and the Momentum delivers. So does my HD600 (even better quality of sound) as well as modified HD 558's. I've tried many headphones that don't hit the bottom or even come close. The Sony MDR-1R that I previously mentioned was such a disappointment.
EDIT: I'm also very familiar with synthetic bass by boosting the second harmonic and it has a characteristic sound that I know all too well, yuck.
1) First I recorded RHA30 using HD215 as microphone:
2) And also Momentum using HD215 as microphone:
3) Next I recorded RAH30 using Momentum as microphone:
4) Next I recorded Momentum using RAH30 as microphone:
On 1) we see dip at 12Hz, and on 2) we see bump at 10Hz, then on 3) we see that bump again as artifact introduced by using Momentum as microphone, and on 4) we see that dip of RHA30 and bump of Momentum at 10Hz they added up to make straight line.
Looking at 1) and 2) we can see that noise floor is 10dB lower for RHA30.
Neither RHA30 nor Momentum can go below 40Hz without distortion. The difference between 1st and 2nd harmonics is 30dB for RHA30 and 25dB for Momentum.
Headphones were driven by T744, which got it's signal through toslink.
I personally think though that harmonics of 40Hz sound on Momentum are more prominent when you listen, because of closed design and resonance. While RHA30 open design is free of such resonance the distortion appears more because of physical properties of the driver, which at 40Hz is pushed to its limits.