4K sets might be expensive and 4K content is still scarce, but if you're an early adopter with money to burn you'll be well served by Sony's X900B series, delivering great looking UHDTV with the sound to match.
No one will be complimenting the X900 series for its slim bezel, thanks to its "massive front-facing speakers" that CNET says "define this hulking TV" and "don't give a damn." But CNET also enjoyed the X900's "other luxury touches," like its "glossy black" veneer and the way "the screen blends seamlessly into the edges where the speakers are mounted." Even as the speakers compromise the X900's ability to look understated, the sound is anything but. What Hi-Fi calls the quality "rich, open and detailed," and CNET says it offers "better sound than any TV we've ever tested."
Of course, all that great sound in a 4K TV is nothing without a great picture, and HDTVTest says that with the X900's "deep blacks by LED LCD standards, accurate colours and linear circa-2.4 gamma," the picture looks "spectacular" and CNET finds that it has the "best picture quality of any 4K TV we've tested so far." If you want great sound to go with your great picture and have the money to spend, you won't be disappointed with the X900 -- just make sure you actually have 4K content to watch on it.