Hi Ron,
Well we did test the same SVS sub (+2), one loaded with the 12.2 and the other with the 12.3 drivers.
What I can tell you is that when it comes up to music performance ( DVD Music - Stereo ) the 12.3 drivers are better than the 12.2 drivers. I already liked the 12.2 drivers very much and did not believe I would hear any difference at all but I am glad the 12.3 drivers have arrived.
If feels like the efficiency has been improved as well as the reaction speed of the drivers. These 2 things really are important I believe for any subwoofer ?
I would say: pro :
-better for music, more balanced sound, more musical
-faster reaction and that also improves HT as well as Music performance I would say. Got the feeling the 12.3 kick harder at around 40/50/60 HZ.
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Concerning the possible SVS sub processor, sure hope it will be something like the VELO SMS1 and hopefully better + cheaper .
Marcel