[Line and pipe]

Hi Guys, I bought a HD428 a month or so ago, now pairing with it an Fiio E7. Run-in for around 1xx hours. This hp is supposed to be a more 'bassy' one as said by Senn but so far its bass is disappointing. But today I tried to press the two ear cup against my ear forcefully with my hands and OMG the bass was so so so much better. More impact and punch, more defined, much clearer and much deeper too.
 
Do you think there are any mod that can produce this effect without me pressing the ear cups all the time?