A big distributor of audio and video products in France, DEA International, has revived the Elipson brand with some exciting new products like the 4260, a modern incarnation of the famous 4040. You can visit their site: http://www.elipson.com
The 4260 is equipped with drivers made by PHL Audio, and designed by Philippe Lesage, the man who helped me customise the Audax driver I used in my SAT speakers. That a sure sign of a winner. I can't wait to listen to this new avatar of a classic! Stay tuned for more news...
They will be exhibiting at the Salon Hifi & Home Cinema in Paris in a month time at the Pullman hotel. More details here:http://www.spat.fr/hifi/
DEA also distributes Canton, Ortofon, Perreaux, Shanglin and Thorens entre autres.

The cabinet

As previously described in my last post, the cabinet was designed as small as possible to match a MIDI system and big enough to allow enough bass.
The final dimensions were set as 200x200x150mm, giving us a 3.9 litres internal volume. The cabinets were provided as a mirror-image set.
This is a bass-reflex arrangement with a 2.5cm diam, 4cm long port generating a -6dB point at 70 Hz.
Because the voice coil is longer than the standard version, one can adjust the bass control on the preamplifier (sacrilege...) and extend the bass output down to 50 Hz without distortion at normal listening level in a small room - which was our target market to start with.
We will discuss in a later post how we increased the bass output with the addition of subwoofer(s)
We had been looking at various materials to build the cabinet, and apart from the obvious MDF, we wanted something that, once varnished, would show the material itself, so we settled on a very dense marine birch plywood, 15mm thick.
We shopped around for a cabinet maker and Philippe Lesage recommended we talked to Jean-Paul Guy of Guy HF in Bourbon-Lancy, a small town in the centre of France, not far from St-Etienne, famous for its manufacture of weapons, and for us audiophiles, where Focal-JMLab and Jacques Mahul operate.
Philippe had said to me that Jean-Paul was rarely taking new clients on, but that my design might interest him.
It is quite a trek from Paris to Bourbon-Lancy, but after a few phone conversations, I decided to go with a pair of prototypes made in Paris.
Jean-Paul asked many questions, listened to our product, and started suggesting a few modifications/upgrades and manufacturing tips: We were in!
At the time, Focal had started 4 years before and was beginning to be a serious client for Guy HF, so much so that it ended up taking 49% of the shares in 2003 and bought the company over when Jean-Paul decide to retire. He is still a technical consultant and the factory is making the top of the range from Focal-JMLab today, as in the Utopia and avatars.
One thing that Jean-Paul was an expert at, among other things, was the varnish: we never found anybody that could do a varnish that was not shiny, but smooth as an anodised aluminium finish. That gave our speakers an elegance that nobody else could match at any price.

The filter

We chose a Linkwitz-Riley configuration because this 12 dB per octave crossover is designed to solve the problem of centering the main lobe of the forward radiation pattern of a two-way speaker system.

This crossover is unusual in that each filter is down 6 dB at crossover (in this case around 5400hz, to avoid the resonance of the tweeter and take advantage of the full range of the bass/midrange driver) and that the two drivers are actually "in phase" at all frequencies when the drivers are wired in opposite polarity. That is, even though the filters have their own characteristic phase responses the phase difference between the two output signals is the same at all frequencies. As a result, each filter section has the same group delay.

This crossover is recommended over the 2nd order Butterworth type due to its accurate summed frequency response and forward pointing main lobe.

We also aligned the two drivers physically to adjust the time delay between the tweeter and bass/midrange driver.
This also gave the cabinet its typical look, showing the structure of the plywood on the edge of the "pyramid" supporting the main driver, a very ancient Egyptian concept. This eventually translated into the name and the logo of the company.

Here is a schematic of the filter  and a photo of its implementation:

A Uni friend of mine was having a party in Poitiers - a mere 300kms away...- and asked me if I could produce the hardware for the sound sytem. He would organise the software, and provide us with travel money, accomodation and cost to build/rent the hardware. It was going to be a huge affair in a large reverberant hall at the Uni in Poitiers.
I can't remember what amplification I got my hands on, but I can remember visiting the factory of Pierre Clement, and imploring them for a "loan" of their new tangential arm turntable, and guess what, they agreed!
Now that I think about it, I believe they also loaned me a Shlumberger Broadcast amp destined to the ORTF. For more info on this product check this excellent website (time to sharpen your French...)http://www.audiofolia.com/clement.php
Most readers would know that Sclumberger gobbled up Pierre Clement soon after
I suppose it is a case of "follow your passion" and it will take you anywhere...
The next step (and time wise, it was the first one) was to build 20 identical speakers. I had in mind that if I could make these speakers in raw MDF, I could them finish them to any finish and sell them afterwards. Some ended up lacquered in white, or black or red. (remember, we were in 1972/73...)
They were designed to be a cube of 30cm when fitted with a grille (always black) on top to hide the tweeter.
Equipment was a full range 17cm from SIARE, and a TW8 from Audax of Elipson's fame- aluminium dome, apparently good up to 40khz. The filter was a simple 2.2uF capacitor for an 8KHz cut-off frequency. The tweeter was time aligned to the main driver.
So, here I am with a very expensive turntable and amp (probably six months of my salary at the time...) 20 speakers (sans tweeter to save space and risk of destruction) , the GF of the time, all to be fitted into a Peugeot 205 Convertible, and torrential rain in a 6 hour drive (no freeway  past the outskirts of Paris then)
We arrive in a fairly angry/exhausted mood to discover that accomodation was going to be a very bare student room, and too late for dinner.
We managed to get a good breakfast the next morning and by mid afternoon, we set up the whole system, and it worked fine all night and the fact this was all in mono did not bother any of the dancers.
We dismantled after the party, packed everything in the car and managed a good night sleep before driving back to Paris the next day.
I ended up selling all these speakers, including a few pairs to a vinyl pressing factory that used them as monitors in their QA department, because of their amazing image and detailing.
I am afraid I don't have any photo of this early design. If you happen to have one, or think you have, get in touch, please!