Running different size subs

[robmorris]

Chaps

I have a sealed 12" in the back of the car at the mo.
I also have a spare 15"/amp.

Can I run them both at the same time or would the 15" just kill the 12" in the process?
I feel that the 12" would deal with certain punchier bass notes whilst the 15" could deal with the other long dirty bass notes?

Whats your thoughts..