The company RDL Acoustics (Room Designed Loudspeakers) was a Roy Allison company which sold speakers strictly by mail order. Unfortunately they folded. Couldn't get a review in a major magazine I guess. Roy Allison designed Allison Loudspeakers and, I think, invented the dome tweeter when he was at Acoustic Research in the '60's.
The speakers are really fine for the money. Probably class C. They have good clarity with excellent highs from the special domed tweeters. The midrange, from 4" cones with rubber surrounds is pretty good too. Lows are from an 8" acoustic suspension woofer in the cube. Lows are tight and punchy but flat to only 50 hz. Positioning the woofer somewhat problematic, but not as bad as most subwoofers.

I wish I had bought the more expensive RDL model now because the power handling on these is not great with the 4" midrange/woofer. Also they are somewhat inefficient--less efficient than a PSB, for instance.

Overall, class B for clarity, class d for efficiency and power handling. Class A for the price. These deserve to mated with good sources. Mid fi CD players cannot reveal what these speakers can do.

A very worthy purchase on the used market for a bedroom or den system. Go with the bigger models if you can find them though for the extra power-handling capability. These are overall a 4. The clarity and highs are really excellent, if you don't mind giving up some bass and dynamic range.