Advice sought on Lowthers.

You may want to check out the Audioasylum.com "high efficiency speaker forum" for info on these speakers. I have only listened to vintage models (in a variety of cabinets), years ago, and they were very bright sounding with shallow bass and had problems in the mid bass area (that was probably a fault of the cabinet design as it seemed to be up too high to be a room problem). I have read about the modern Lowther models, but have not auditioned them. The new models have redesigned voice coils which allow you to tailor the sound to your room and setup and there are many models of both the speakers and the enclosures to choose from. I am not saying that the new versions are bright (as I, again, have no experience with them) and would be interested in hearing them myself. The speakers that I listened to in the 70's and 80's were probably manufactured in the 50's and 60's as they had been salvaged from the used market by some hobbyist's that I knew at the time who were also experimenting with Jensen, Alnico and Electro Voice speakers (pretty sure that those were the brand names).

A friend uses and sells the Beauhorn Lowther (top-end) speaker. He has had great success with the speaker. It is fast, transparent, detailed (but not overly so), coherent with good highs, mids, but limited deep bass (need a sub).
If I were going to low powered tube amp, this would be the speaker to try out. See www.soundsofsilence.com for more info and product links.

You could look at two sites for radically different uses of Lowther drivers: (1) www.welbornelabs.com, "Oris Page", and (2) Lowther America (not sure of site designation). The difference is between a front horn (plus supplemental woofer NOT subwoofer) and a folded horn, in which the Lowther driver supplies the bass. The latter design is acknowledged to be extremely tricky, and Dekay's comments are well taken. Proponents of the front horn approach don't like the folded horns, while proponents of that approach seem to really hate the front horns. I'm getting an Oris 150 horn myself, and will know in a few weeks what I think. But no one doubts the quality of the Lowther drivers and the advantages of their high efficiency, which pays off not only for low power amps. The voice coil doesn't have to move as far, and so can be faster and more accurate in its movements.

I just purchased a pair of Beauhorns, probably through the same "friend" that Mento mentions in his post. They are big, expensive and not without flaw, especially in their lack of bass - Mento is correct. You must use a quality subwoofer (I have 2 RELs). BUT, when if you get them even part way dialed in - after 2 days, I figure I'm about 1/2 way there, with much "tweaking to do" - you will hear immediately what all the fuss is about when it comes to high efficiency horn speakers coupled with low powered SET amps. There is a naturalness and ease of presentation that is absolutely captivating. As a part of the "naturalness", these speakers have the ability (well-almost) to the project the volume, scale and proportion of real performances without strain, well beyond normal-sized dynamic speakers. I suspect that the big planars (Magnapans, etc.), line arrays (Pipedreams), and dynamic giants (Wilson Wamm, JM Labs Utopias, etc.) can do the same and maybe more, but these speakers are much bigger still (and in most cases, much more expensive too). My previous speakers, Merlin VSM-SEs beat the Beauhorns in some respects that many may value very highly (I did and still do) - image focus and "palpability" come to mind; also frequency extension in the highs and ultimate transparency (which may be related) - so these Lowther based speakers may not be everyone's cup of tea. However, they are worth a look. Believe me.