I have always been curious about the ER4; I don't mind deep fit, but I am just worried they won't have the bass I want. I love the tonality of the HF5, but I couldn't live with so little bass. If the ER4 has less significantly less bass than the UERM, I probably wouldn't like it.
It has very similar bass to the hf5. But it's flatter overall with much better treble. The orange filters will give you more bass without affecting the treble too much. People compare the treble between filters, but the difference between filters is much less than the difference between other earphones. The orange brings the bass to a much better level if you are worried and want a bit more than the er4s/hf5 bass but not a bass cannon. I can't speak for the uerm, but it sounds like it's similar bass but a bit more... Would you say the uerm has more bass than the orange filters gnarlsagan?