Till now the market has not digested the news of Sony's best series Xperia Z3 launch all over the world and there is spark that Sony has already started its work on the successor of the Xperia Z3 i.e Z4 .
Recently Sony had launched Z3 which is a decent upgrade to Z2 or they have done nothing new or impressive work on it . Whereas rumors are that Z4 will be having overpowering features in it.Major change in Z4 will be the enhanced sound quality of the speakers by adding the amplifier in it . But the question arises that will it be enough to compete with its rival htc's dual speakers?? For that we have to wait till MARCH 2015 for its launch .