Lowther Belcanto
full-range horn speaker


BORED WITH MY SPEAKERS
I'm having some problems with my current speakers; I just don't like them anymore. My equipment surpassed these speakers quite a while ago but I haven't had time (or the money :-) to do anything about it. It seems I am beginning to get fed up with most of my equipment, I've been spoiled by equipment I've heard elsewhere during the years.

SURFING SURFING...
Then I got my Internet connection last february, boy was that fun. I started browsing all over the place, for no apparent reason either. It still hurts when I think of the bill I got that month. One day I was getting bored because I couldn't find any more interesting sites; so I thought! I opened up a copy of Klang & Ton, a german DIY speaker magazine. Somewhere in the back amongst the classifieds I saw an add for some strange looking speaker called "Lowther". It looked pretty ridiculous with that strange egg-shaped diffuser on the front. I started up a search engine and typed in Lowther, I thought it might be good for a laugh or two. A few seconds later I was roaming the Lowther Club Norway site and printing everything I could get hold of. I was really interested in what these units had to offer.

Some of the links on that page led me to the Lowther Club Holland. PERFECT, that's the country where I live.. I immediately sent an e-mail to Bert Doppenberg, who runs that Lowther Club, asking for some info and prices. The next day he answered me and one thing led to another. About three weeks later Bert invited me to come and listen to his horns. It wasn't what I was planning on building but it would give me an idea of the sound. That weekend I drove a little more than 125km to Bert's house. When you think of it, it sound pretty crazy. But hey, that's me...!

LISTENING SESSION
I arrived at 13:00 (an hour early, traffic was never this light!!). Since Bert works night shifts I was afraid he would still be in bed, and as it turned out I wasn't wrong about that. After listening to his Lowther system for a few hours I was hooked. I was 100% sure that I was going to use Lowthers in my new speaker. It is a single unit capable of reproducing the entire audio spectrum at an astoundingly high efficiency. The units aren't cheap, but if you compare it to a three way system of the same quality, the Lowther is a lot cheaper. It doesn't require a complicated filter, you need only a fraction of the wire since you only have one unit, and it can produce more volume at the same power. "I was in love with it's sound" springs to mind. After another few hours of enjoying Bert's speakers we decided that the BelCanto cabinet was best suited for me. Size wasn't a real issue and I wanted to use the PM2A unit. The BelCanto would give the best results Bert assured me. So homewards I went, around 18:30, dreaming of those great speakers I was going to build.

BUILDING
A few days after that I went to the local home-improvement store and bought several boards of 18mm multiplex. I was surprised at the cost for all the wood, in a positive way. It was much less than I had thought; but that's always a nice surprise, we dutch people are very cheap ;) The following weekend I started marking the wood so I knew where to cut it. All together each cabinet has about 22 panels in it. After placing all the internal panels on the side board it all became very clear, it seemed harder at the beginning than it actually was. The only thing to watch out for is that the angles at which you cut the boards are the same as on the drawing. I've placed some pictures which show the various stages of building.


After five weekends of sawing and sanding I finally had two almost finished cabinets. I only had to place another front board because my unit would be too long to fit into the front, thus I had to add 18mm so that it would not touch the panel right behind it. Also I would need a base since the horn mouth is at the bottom. Bert called that week that my units had arrived and that I could come and pick them up. Sheeesh, they were actually waiting for me to place them in my cabinets, what an excitement that was. I went to get the units and quickly returned so that I could place them and listen to them. Bert warned me that they would sound pretty aggressive the first several hours, but I was too anxious to wait until they were broken in. Boy was he right. Even now, after 200 hours they don't sound right yet, they still miss that smoothness I heard at Bert's... It is getting better every day now, I just have to hang in there a few more weeks.

Bert "volunteered" his services to build the bases for my horns. He made plans for a tractrix shape that would fit under the cabinets like a pyramid. We had plans to place a hydraulic lifting mechanism to raise and lower the cabinet so it could be adjusted to the room. Those plans were dropped pretty quickly once I saw how much work would go into making it. We decided to just see how high the cabinet would be placed to get a nice sound and then just place a wooden frame underneath it. We also dropped the idea of making a tractrix shape for the base. The two different lengths of the base (rectangle instead of square) made it almost impossible to get a good tractrix base. A simpler pyramid shape was made by Bert, I'll place pics of these in a short while.

In the meantime I can now place that second front panel and sand the whole cabinet so it will be ready to put on the first layer of primer. I still have a lot of work to do though, more on that later.

UPDATE!

I could have sworn I added more on these speakers since I finished them about a year ago. Must not have been paying attention when I updated my site again and dumped the new HTML for this page :(((

Anyway...



The proverbial drawing board




Sawing the first panels (done by my assistant ;)



Top-, back- and side panels



All the panels laid out

 


My trusty assistant at work glueing together the first panels



Almost all internal panels placed



All panels in place, I foamed up the compartments



Cable throughput now in place



Putting a little weight into it...



One last look before it is closed forever



Video cassettes as a base, brilliant!



The speakers set up for listening

 


Close-up of the PM2A installed into the cabinet



SCHEMATICS


Jim de Kort