There is no misunderstanding.
To my ears, earbuds provide substantially more bass than IEMs and closed-back headphones that are even known to be 'bass-heavy'.
There is no reason to speculate - we all have different ear anatomy so our experiences will naturally differ.
(IEM's I've owned or auditioned: Sennheiser Momentum, KZ ATE/ZS10/ZS10 Pro, Shuoer Tape, Tin P1, RHA T20, Shure SE-846 and a few other lesser known IEMs)
I have directly compared my JVC HA-DX1000 with Sabia V6, and the earbud was bassier.
Of course, if I take the foam off the Sabia V6, the JVC will be bassier.
If you push your earbuds closer into your ear canals, or simple change the angle of the earbud driver (manually with your hands) you will also be able to hear HUGE amounts of bass too.
It's only fortunate for me that my ear anatomy naturally allows the bud to rest close to this 'very' bass-heavy position.
For outdoor use, I don't need to turn the volume up higher than usual (compared to the volume I would use with closed-back headphones) because I don't miss any of the bass performance.
Actually when you refer to "bass" do you refer to
midbass or
subbass? Perhaps we are all referring to different points of reference?
I'm a basshead, and I personally find most earbuds lacking in
subbass extension and quantity (probably related to poorer isolation of buds, maybe also due to tuning of buds to be more midcentric/bright in general?). The
subbass frequencies (which I consider as 60 Hz and below) are usually "felt" rather than "heard" as a visceral
rumble. The
midbass frequencies (which I consider as around 60 - 200 Hz) provides the
slam AKA punch AKA thickness in the bass frequencies and are the basslines that one can hear in music when a double bass or bass is playing. Buds can provide quite good
midbass quantity and "slam" for sure, though I would agree with most of the others that buds in general won't trump most basshead IEMs cause IEMs have a better isolating seal in general (bass frequencies are usually the first to be lost in poorer isolation). Same issue with open back headphones, they generally lack in subbass extension to me.
I've not heard much
subbass subjectively on my buds in music and objectively with tone generators, they seem to roll off around 60ish Hz, and I'm on the lookout for a earbud with good subbass extension/quantity, anyone can give some recommendations??
Though of course we all hear differently, and have different bass tolerances, different ear anatomies, different music genres (thus requiring different amounts of sub and midbass), different sources, different listening volumes (Fletcher Munson curve affects different frequency loudness with different volumes), so as usual, YMMV.