For my personal taste the A8 provides more than enough bass. But it is strongly recommended that you use the foam things (I actualy don't know the english word for it) ;-) to let the A8 sound good enough.

By the way: The A8 seem to be improved over the time. My 4-5 years old A8s where broken and I bought a new pair last week.
My new A8 play louder on the same volume level than my old ones and they have a richer bass than the old ones!