Do you remember when a car stereo was pretty good even without a sub?
this may not really be about headphones buttt... its audio related
just helped my friend install a 1400W sub 12" bass speaker.
also installed some kickers to help with the punchiness.
But now for a little something i learned from this.
having two of the same size speakers does not double the decibals (volume) of the sound. once a speaker is loud enough to vibrate all of the air in the car, any additional speakers wont do much. now if your single speaker doesnt move all the air, then two is needed to full out the sound. helpfull info!