[JoseK]

Hi,
 
I was wondering what is the preferred setting if I have 2 separate volume controls(portable player and cable attached control on UE 400vi)?
Should I max out the volume on cable attached volume control and set the level on the player?

 

[JoseK]

I don't have these headphones yet but are those cable attached volume controls of UE 400vi only for iPhone? Does those controls work even if I don't use iPhone but a regular portable player?

 

[DrSheep]

1, generally you want to use your DAP for main volume control and the in-line volume control set to max and volume triming when necessary.  This way you will never bump up your volume to unsafe level by accident.
2, those Apple approved 3 buttons in-line controls are for iDevices only, and Android or any other DAPs won't work.