Custom- molded in- ears place the speaker driver( s) and nozzle in a case that’ s molded to the exact shape of your ear. For the price it is truly worth it. Wanted to wait and write this review after I had some time to truly review the product. The Westone UM2 is among the best I have ever heard.
Um2 dual driver true fit earphones. This requires that you make a visit to an audiologist, who will make an impression of your ear that’ s then used by the manufacturer of the earphone to make the case that holds the elements of the earphone itself.
As with full sized speakers, having more drivers generally means getting better sound because each driver is handling a narrower frequency range or, combined, the drivers are covering a wider frequency range with more efficiency and clarity.