It's time to now discuss my single biggest complaint about Elmo's BOXi pocket projector:
It has a high pitched fan whine. It's nothing so loud to be insurmountable, but, let's say you are done using your BOXi for a small business presentation, where the noise wasn't a problem, you wouldn't have to shout over it, or anything. Then, perhaps you find yourself back in your hotel room, ready to shine the BOXi on the wall to enjoy a movie.
You will notice the whine on quiet scenes. It's not devastating, nor is it likely to even measure overly loud, it's just not a good frequency, and the pitch does change as the fan seems to run at a variable speed, likely speeding up automatically if it starts warming up.
Fan whine on pocket projectors is nothing new, and I've not yet encountered a pocket projector where I found the whine to be so offensive that I wouldn't recommend the projector on that basis.
Again, the whine would be only a minor inconvenience if you are using the projector for a presentation to two or three people no more so than some other projectors which might be lower pitched, but louder.
That said, I don't think I'd want to watch a music video on this projector when the music is mostly soft with lots of pretty quiet passages with this projector. Of course, I really wouldn't want to be listening to serious music on a one watt sound system either.
The good news: I eventually concluded that if it's just me watching / listening, I'll just take out my good Shure earbuds that are noise canceling, and enjoy the music on high quality earpieces rather than a too small speaker devoid of bass. You can figure out your best plan!