Based on the information found on the official website, there is no Echovox compatibility. I have searched on the product page, but nothing is mentioned. However, there is a compatibility section that specifies the following:
For Audio Playback - Smartphones, tablets and other devices that support Bluetooth® wireless audio profile [Advanced Audio Distribution Profile (A2DP)] or 3.5 mm audio output.
Phone Calls: Phones that support Bluetooth® Hands-Free Profile (HFP1.5)
You can check for additional info using the following page: http://origin.ultimateears.com/en-us/ueboom2