You have to remember the original design purpose of the LS3/5A. The BBC wanted a small speaker for use in mobile vans for monitoring and mixing when recording or broadcasting from off-site locations. They were particularly interested in how well the speaker worked with the human voice. They do that job extremely well, but it necessarily means they lose steam quickly as the room they are used in gets larger and higher volume is wanted - particularly with lots of bass. Comparing them to Tannoys, even the smaller ones, is a bit of an apples and oranges thing.
