General educational reading. Not professional advice. For hearing symptoms, safety decisions, or medical concerns, talk to a qualified professional.
The seal is the bass
Most earbuds rely on a tight seal between the ear tip and the ear canal to produce low frequencies. A bad seal makes a $250 pair sound like a $40 pair.
Try every tip in the box
Manufacturers ship two or three sizes for a reason. Most people use the size the buds come fitted with and never try the others. Spend five minutes; it is the cheapest upgrade.
Foam vs. silicone tips
Foam tips usually seal better and isolate more passive noise. They are less hygienic over time and need replacing every couple of months.
If buds still hurt
Some ear shapes simply do not fit some earbuds. On-ear or over-ear headphones, or open earbuds that rest outside the ear canal, are reasonable alternatives.