ok, bass is about movement, your not really suppose to hear good deep bass, if you can hear bass then its called boom, boom is seen as bad on head fi but for earphones its the only way we can have bass present in music, so by keeping the boom down etymotic claims its more accurate but in reality its just light bass.
one things certain and that is without boom earphones would not produce bass period! the drivers are not big enough to produce enough air movement to create deep bass, if boom is bad then so is bass because we need boom to hear it, and if no boom is heard then where exactly do you hear the bass?
the problem with etymotic phones is they dont really boom and so the lower frequencies are gapped and light and just not really there between 60-150hz, its a big gap that booming earphones manage to fill
vocals on the other hand, be it female or male register best around 3-4khz and this is a strong point of the ety's