TJL3W ribbon version

This was the initial plan for a three-way TJL. The W12 stuck in between the W18 bass and the JP3 ribbon. However, the HIQUPHON OWI did so well with W12 that I wanted to explore this option first.
So, the test front panels needed some further routing to accommodate the JP3s, having a much larger frontplate diameter. And what I hadn't taken into account was the depth of the JP3... Had to cut a hole in the rear panel of the mid enclosure. Hmm...Should you want to build the TJL3W with the ribbon tweeter I suggest you increase depth of mid enclosure to avoid what I had to do. Image below.


Room for ribbon tweeter.


Finally, test front panel with Fountek JP3 ribbon tweeter.

TJL3W-JP3 crossover


Simulation and FR prediction from JP3 option: Bass crossover section is the same as for the OWI tweeter.
Mid section has a single change: 12.2 uF is replaced by 6.8 uF.
Tweeter section: This is completely redesigned to incorporate the JP3 ribbon.


The 4R7 series resistor produces a flat response with my homemade alu ribbons.
Should you use the original JP3 ribbons you may have to use 5R6 due the originals
having an approx. 1 dB higher sensitivity. Check out 4R7 to 6R8 to get the best tweeter-mid
integration. My guess is that you should use 6R8 with the original ribbon.


Tweeter section or the JP3 version. 3R9 was substituted with 4R7.


Mid-section for JP3 version; new is only the 6.8 uF capacitor.
Try 3.3 ohm for input series resistor. You can fine-tune the 900-3000 Hz range here,
but don't go below 2R7 and above 3R9.


Midrange section, JP3 version. I have tried to make a logical layout, starting from down left towards right
and then up, followed by the notch filter (4.7 mH + 10R + 1.5 uF). I finally decided using 3R3 to mid.

JP3-version measurements:

FR at 1 metre distance at between-mid-and-tweeter height. Quite a nice response. This from the left speaker. A very flat and revealing tuning indeed but no aggressive mid or treble from this set-up. The W12 and JP3 ribbon tells you right away what's going on.
Red is with same mid and tweeter polarity. Blue with reversed ribbon polarity as it has to be.
3R3 to the mid and 4R7 to the (homemade) ribbons. Try 5R6 to the original JP3s.
JP3s available here: GM Sound - Produkt 2
I'm going to have a pair of the new Fountek NeoCD3 in a few days and I'll try if these laminated ribbons are as good as the true alu ribbons.

How about left and right speaker? This is what we usually do not see. Red = left speaker. Blue = right speaker. Up to 2 kHz there really isn't any difference. From 2-15 kHz we're talking max. 1.5 dB difference. Not bad at all - from ribbon tweeters. From my experience ribbons are not as consistent in frequency response as domes, and I need to make a new alu ribbon for the right speaker. The small peak at 12 kHz is most likely caused by a little too tight ribbon. Needs to be loosened a bit.
But +/- 1 dB is excellent. Actually it's amazing we don't have any documentation for frequency response and impedance when we buy a pair of speakers. You get more quality control when you buy a toaster compared to buying a pair of speakers.

So, that's it. The TJL 3-way. It's taken some time and it's been quite a journey into classical three-ways with a small upper midrange driver.
It's playing in my living room and this is going to be one of the stock speakers in my collection. A small sized speaker with a very neutral presentation, high level of transparency, a very flat voiced speaker that tells you most of what's on your CDs and LPs. A speaker with a surprisingly deep bass considering its size. It doesn't go as loud as the Ekta, but again, the Ekta is a bigger speaker. Generally it's a more neutral speaker compared to speakers with paper cone drivers.
2 x 50 valve watts do well here.