The SE420s employed a dual driver design and produced superb sound across a whole range of music. The SE310s were considerably cheaper than the SE420s, but didn’t quite blow me away in the same manner. In fact the problem with the SE310s is that the price wasn’t quite low enough when compared to competing products, like the Ultimate Ears super.fi 5 Pros. But the SE210s that I’m looking at now could well be the best value, high-quality earphones out there.