Need help pairing a sub

[KASR]

Ok, so I want to pair my existing sub - but unfortunately I can not find the exact sub that came with my 5.1 set (you can see it here: Polk RM6750)

So the question is: is it better to buy two separate matching subs for my Polk satellites or can someone recommend a Polk that matches well with the existing one. Thanks in advance!

 

[zumbo]

Sub doesn't have to match, unless you just want it to have the same name on it.

 

[jostenmeat]

Sub doesn't have to match, unless you just want it to have the same name on it.

Its generally true, except that smaller satellites might benefit from subs that maintain linearity into higher frequency range. Of course, if one is bumping up the x-over, you'd want the sub(s) close to the sats.