PROJECT 1: full range transmission line / d'Apollito speakers

PROJECT 1 is in fact the "son of project zero".
I liked Project 0 so much, that I persuaded a good friend of mine to copy them for himself.
I had no idea what I was about to get into. We shared the job between us. He was financing it and endlessly complaining.
I was designing, shopping, cutting, gluing, screwing, sanding, stuffing, drilling, tweaking and reworking.
It took us a year to do it, but I learned a lot in the process.

For the tweeter I used Scan-Speak 9300. Better than Dynaudio 28/2.
For the mid I was told to try the Scan-Speak 8640 13 cm. I used it in MTM config. At that time I had no idea how good this driver is. It looked just OK.
I absolutely adore that combination, although I would now prefer 9700. The fact that I used two mids created a sensitivity problem. Mids are too pronounced compared to the bass. But in very small room where they play plus TL response it sounds acceptable.
I could not get the KEF B139B bass driver (the stadium), so I found a driver with nearly identical Thiele - Small parameters. The Rockford Fosgate 10 inch car driver. Heresy, huh?!
I put it in the transmission line, having really no idea how to do it right. To this day I don't know.

Anyway, these speakers took a century of listening to tune the XO by trial and error. U had at that time no tools and no knowledge how to measure and what really to look for.  I was just trying to please the owner so he gives me a break.

In the end It is a hell of a musical loudspeaker. The present owner loves them to no end. I
do too, even though I remember many stupid mistakes I did. Still the absolute magic of 8640 covers for any mistakes elsewhere.

If my memory serves me right, the XO was like this:
Bass: 8 mH series, (2,13 mm wire) 10uF parallel (essentially a 1 st order lopass with extreme HF shunt capacitor)
Mids: 100 uF PIO capacitors series, 0,25 mH silver wire coil series.
Highs: 4 uF series, 2 Ohm series, 18 Ohm parallel.

updated March 04 2002.

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This 13 cm little sucker is a great midrange driver. Ultimate detail. Female voices and violins sound awesome. Shame it will disappear from s-s offer.
4 gm moving mass, silk dome as a dust cap that is identical to the tweeter dome, rubber suspension, huge X-max, very low resonance etc. 
This bass driver is very nice. It has a 23 Hz F3 and very lively, punchy sound as the name suggests.  At that time I thought that MTM is a magical solution to every problem. Apparently it sounds very nice, but arguably better than simple MT. Anyway, that is what I did. Below the MTM you see TL opening. It forms a sort of poor man's  "WMTMW" with the bass driver. The line has 2,4 meter and is very lightly stuffed and lined with thin coat of wool felt. Both mids share common sealed sub enclosure.

Look at that cool stand with adjustable screw spikes and a steel frame.. The XO had to be outside to allow for 25400 small adjustments that I made. It forms the ugliest backpack that I have ever seen on any speaker. Currently P-1 serve at Peter's who drives them with ARG SET 15 WPC amplifiers and SILK AC filter plus a great sounding Kenwood  CDP.