Ti is not just the moniker for the original tweeter version. Ti was the original version of M1, M2, M3, M40, M50, M60, M80, VP100 and VP150. I think that was right around 1999. I'm not sure about the 100 and 150. Ti stands for titanium according to Doug Schneider of Soundstage. I am assuming he was told that by Axiom. I have also seen Axiom call the Ti the v1.
After the Ti, Axiom made improvements. Between the Ti and v2, I think the audible improvements were mostly related to the cross-over. Sometime around mid '06, the v2 came out. But some marked Ti are actually v2.
My take, from the history I've gathered over the last 13 years, is that Axiom struggled with the highs on its speakers. They tried to fix this in various ways mostly through the cross-over. The struggle continued into v3 (summer 2010 intro) and didn't end there. The v3 tweeter could handle more power and was more dispersive and resulted in better imaging. But it still wasn't a grand slam. v3 also brought cosmetic, functional and performance changes through aluminum dustcaps, re-designed woofers, and cross-overs and magnetic grilles.
Someone eventually said this shit's got to get improved for real and that was the birth of the glorious v4 in early 2014. Andrew really re-designed the tweeter this time (LOL!). He gave it a die cast aluminum face plate for better rigidity and cooling, a larger rear chamber to lower the resonance frequency further below the crossover region, and a new horn to be smoother off-axis above 12 kHz. v4 continued to bring a whole bunch of other very significant changes as well that I've covered before. Finally with v4, we have glorious everything including soundstage width and depth, focused imaging and placement of those images on the soundstage.
Unfortunately, as you know from Rebulx's experience and I know there's at least one more on this board, some listeners' ears-brains got real messed up from listening to the tweeters of Ti to v3 and now they think those are the cat's pajamas when in reality the land of milk and honey is the v4.
I may as well add that some have said the changes throughout the last 20 years are only "a matter of degree" and they are all "similarly good". I really don't know what those statements mean but my ears-brain say BULL CRAP! I had the v2 for a decade only to be shocked into reality when I lined it up against the v4 (including the sub) and listened. I was robbed of owning the v4 earlier because I took the BULL CRAP as gospel.
Do yourself a solid and upgrade to v4 if you have v2 or earlier. I don't know about v3 because I've never heard it.
