The most important factor in making sure that your earbuds fit correctly and that the sound (especially bass) is optimal, is choosing the correct size ear tips for your ears.
The M100 comes with small, medium, and large silicone and small and large foam ear tips included. We would recommend trying the full range of tips provided, so you can find the right fit for you.
When trying the foam tips, we would suggest fitting them by following the steps in the image below:
Remove the eartips from your earbuds.
Firmly press Memory foam tips onto the soundport. Ensure the tip is secure before use.
Once installed, roll the tip between your fingers into a thin, round cylinder.
Gently insert the entire eartip into your ear and hold it in for 10-15 seconds.