Two subwoofers


Simple question: If you have two subwoofers in the same system properly placed apart and balanced in the room, should they be exactly the same models, amp types and and have matching power outputs? Is it possible if you have two different types that they could be out of sync? For example, if one is a class AB analog amp at one power output and the other a class D digital amp at a higher rated power output, could they be out of sync even slightly?
pdn
Where you get the SMS 1's? It is not for sale on the Velodyne website anymore. I want to use two for my setup.
Thx.
Audioquest4life
I bought the two SMS-1s from a guy in Wyoming, I think. It was probably a listing on Audiogon.

db

congrats you are happy ! are the new subs servo controlled subs ? and what size are they ?
i think there are a # of YT videos extolling the value of multiple subs and i think it is a no brainer now proven they work
are those vented or sealed ? some advocate using bOTH!
I am going to try open baffle servo subs 12 "
some chaps elsewhere were debating "fast bass:" which ( to me just means it is controlled better like w/ servo subs and i am quite sure the servo subs are MUCH better than they used to be) older ones had reliability issues

funny why is it all the old guys think speaker tech just STOPPED! like 20 years ago and new speakers and subs are not better ? ? are they just lazy to keep up ? so just dismissive ?
reminds me of some of the old profs at university who just were resting on their laurels and had not done any noteworthy research in years ! we always wondered if their brains had atrophied ?
when i watch the good , honest reviewers on YT like New Record Day, Audioholics etc they sure seem to be saying the newer are better and say so! even prove it w/ measurements ! ( and YES they are LISTENING too! -love it when some curmudgeon intones whining "but do they LISTEN " to them LOL 
i am thinking of using sub for almost ALL the speakers in my 11.2 HT system! 
i found adding a sub to my center channel certainly is valid it only does below 80 Hz or   so it seems there is info there to be heard below what the speakers like to produce sadly the BEST audio is during commercials! often not shows or movies!
thx for any helpful comments