With the SE420, we really break out of the category of the two models below, the SE210 and SE310. Contrary to the latter two, it’s equipped with two distinct audio drivers per ear.  One handles the reproduction of highs and mediums and the other manages basses.  The SE420 are surely bigger earphones, but luckily this isn’t felt too much in their weight and they can be worn without the slightest impediment.

Here is a diagram of the SE420's components :


1.    Interchangeable sleeves to adapt to all types of ear shapes and sizes
2.    Output filter
3.    A cord that splits in the middle for connection to a remote
4.    Audio filter which directs the different frequencies to the appropriate audio driver
5.    Tweeter : a speaker devoted to highs and mediums
6.    Woofer : a speaker devoted to basses
7.    Enclosed speakers
8.    Cable

In tests, the supplementary second driver clearly added a plus to sound definition.  Details come alive and basses are indeed noticeable.  However, surprisingly they still lack a bit of volume and we are almost left a little unsatisfied here.  We already tested the SE530 and experienced sound quality that of course isn’t comparable to the SE420 and even less so to inferior models.  Either way, these are quality headphones and they clearly offer better performance than the SE310.