Is this TV good for a bedroom?

Yes. At 40 inches and 1080p it fits a bedroom or small room well, and the Roku home screen keeps apps and live TV in one place. It is not bright enough to fight strong daylight, so avoid placing it facing a sunny window.

Does it support 4K or HDR?

No. The panel is 1080p Full HD and the set does not list HDR support. Streams play at up to 1080p, which is fine at this screen size but a step behind 4K rivals.

Can I connect a soundbar?

Yes. One of the three HDMI inputs supports ARC, so a compatible soundbar can carry audio over a single cable. There is also a USB port for playing files from a flash drive.

Does it need a Roku account?

Roku asks you to sign in or create a free account during setup to load channels and keep them updated. Over-the-air channels work through an antenna without a paid subscription.

How does it compare with a 4K TV of the same size?

A 4K set will look sharper up close and usually offers better HDR and brightness. This JVC competes on the Roku interface, three HDMI ports and simple setup rather than picture quality.