Bear in mind there are Mark IV Audio and later EV Telex versions. If I had to hazard a guess, the rough back cones are Mark IV and the smooth ones later cost cutting measures. Non pressed cones tend to have lower bass response. I haven't done comparisons.
If anyone can use this info, Voice Coil is a speaker parts and speaker publication. Digital is free. Just make up a company name.
Voice Coil Magazine | audioXpress
Bookmarks