I just modeled the EVM-15B in a 3.5CF box using a 16 sq. in. port 1" deep and the displacement at 200 watts RMS is 3.3mm from 40Hz on up, So 100 watts displacement limited is not accurate. I also think that the Xmax on the B-PL is higher than 3.3mm.
I also do not know why they show the same electrical specs unless there is a difference in VC conductor properties between aluminum and CU clad AL, or possible there are different versions that apply primarily to the OEM market (at that time EV was a leading supplier of high performance components to other companies such as Fender, Mesa, etc). Using the 1/2-space driver efficiency, and the motor being the same, the difference between the B (4.3%) and the L (6.2%) is likely in part to be due to a longer winding height on the B. I show the B pro line at 0.625" and the L at 0.500" but some of my info shows both at 0.500", and some show both at 0.625". I know for sure that the original L's had an aluminum VC and pretty sure the B's had Cu clad... at least in later versions. The DL, which I am pretty sure uses the same VC/bobbin as the B-PL (but some magnetic circuit improvements like flux demod.) shows an Xmax of 4.1mm which would be the roughly 0.125" longer winding height. I will agree that there is some conflicting information though.
Incrimental improvements in a model over many years can lead to confusion, and generally, older recone parts are discontinued in favor of reconing with the latest revision when mechanically compatable. This is true with most manufacturers, and in the case of EV, I am pretty sure all recone parts are based on the latest pro-line type parts, that's what I use anyway.
