Room-to-room portables are best understood as standard lightweight mainstream projectors that add their own robust audio systems, so you don't have to hook up external Bluetooth speakers. Until recently, the conventional wisdom for setting up any projector for a home theater or home entertainment has been that if you're going to go to the bother of getting a projector, you'll want a better audio system than any projector can fit in its case. For projectors that were light enough to move easily from room to room or to the backyard to watch a movie, that typically meant that you also had to lug an external audio system with it. Room-to-room portables solve that problem. Most make extra room in their bodies for a worthwhile audio system by being about twice the height of a typical standard projector, making them cubical, or close to it. A few gain the extra space by using an oval shape instead. Because these models aren't meant to be moved far, they can be heavier than other categories of portables, and have a large range of weights. The lightest we've reviewed is just over 3 pounds. The heaviest is more than 14 pounds. Most other specs vary tremendously, as well, so you have plenty of variety to choose from. Among the models we've tested, rated brightness ranges from 300 ANSI lumens to 2,400 ISO lumens (equivalent to ANSI lumens), native resolution ranges from 720p to 4K, and display technologies include DLP and three-chip LCD. All use either LCD or laser light sources. Most require AC power, but a few of the lighter ones include onboard batteries, and a few of those are drop-resistant and water-resistant, making them particularly appropriate for carrying to the backyard. As with mainstream mini projectors, many can also double as Bluetooth speakers. All the models we've seen also offer smart TV for streaming, most often in the form of Android TV, which is either fully integrated or supplied on a dongle—sometimes with a second remote.