So, I bought a Fiio E10 for my computer to get a clean sound from it instead of the bad integrated sound card sound (its a laptop). I used to have a Panasonic djs400a which you can turn the volume so high that your ears will sweat, all this with the Fiio on L gain instead of H. In fact if I set to H gain it start clipping as if it were too much for them.
Then I get some money to spent on a 50-100 dollars headphones and was looking for something over ear. I looker the 4*9 Sennheiser product line and see the comparisons of 429, 439 and 449 here. I chose to buy the 439 for be the more bassy and for the dettachable cable like the beats :P. Then I plugged my 439 in the Fiio and noticed the volume was low compared to the Panasonic which was very loud on L gain. Then I move the switch to the H gain the amp, but the amplified bass started to sound like clipping or distorted. So I did the bass mod on this and the bass stop to clipping on high gain but still feel the panasonic which are cheaper can get louder than my "audiophile" 439.
What is the cause of this sinces both cans are 32 ohms impedance and sensivity on the Panasonic is 102 db/mW and in my 439 is 112 dB/V.