I found all the sizes of the JBL 2311 horn and also who is able to "print" the horns in ABS in 3D. Measuring the JBL 2445j driver which is claimed to be a two inch, it actually has a mouth of less than 50.8mm / 2 ", around 49mm. Since I'm remaking the horns, I have to do the throat 50.8mm / 2" or lower?
Giuseppe