Mixing svs sb3000 with sb 4000

[Stones]

Hello, I just bought a svs sb 4000 and if I decide to add a second sub later for the back of room would a sb 3000 work?
I bought the sb 4000 because of the great deals SVS is having right now ($1299) but I assume they will up in price by the time I’m ready to purchase a second.
with the 3000 being much cheaper but similar specs would they sound good together or will I need to get another sb 4000 when the time comes?
Thanks

 

[carlosmiguez75]

Ideally, though, if you can get another SB-4000 down the line, that would give you the smoothest, most balanced experience.

 

[j_garcia]

You are better off with matched 4Ks unless you will manually tailor each one or have the ability to independently calibrate them.