They sometimes have trouble reproducing complex audio patterns that plus's dual drivers presumably reproduce better.
Mine have some pretty heavy tweaks via PowerAmps equalizer and the Neutralizer app.
I don't use the audio profile I set up on Neutralizer but when it's running in the background the sound is better.
Whatever... I'll run with it
Also use the Wearables Equalizer many times too on top of PowerAmp, either Soft or Dynamic and sometimes Dolby.
PowerAmp is the one that you wanted to dial in the lower bass curve of the buds. A lot of set up but it's the best HD player out there, you can then save the settings and playlists. PowerAmp's equalizer has a preamp setting and an auto limiter that completely prevents clipping on the bass so you can drive as hard them as they can go on the bass lower frequencies; 31hz is the last slider adjustment point. They might catch a little in the high 30's if you boost that band through the roof ie +10db
Make sure to make smooth transitions on the 3 or so adjacent sliders of the equalizer though. Cut it back a decibel or so at 1khz as they have a bit of spike there.
If not for -all- that I be saying BLAH!
However with all of that plus the most recent firmware updates I saying

I'm using them everyday to listen to music and movies.