i am currentley running a older rockford 250 for my front end and a have just picked up a bd1000 to run my 18" inhuman. i also have a zappco ag 750 that is sitting in my basement and i was looking in the manual and they have a diagram on running a full range system with a 4 ohm sub bridged between the two channels w/crossover. i was thinking of ditching the 250 and putting in the zappco with a 10" or pair firing forward to fill the gap of the 18" or to have a little bottom end when i have the 18" turned off. any thoughts on how this would work out?

 

It's for sure possible but most people will be better served to keep different drivers on different amp channels and use an active crossover - especially when dealing with subbass.

 

I don't recommend your idea Cliffy.

You won't want the 10's playing at the same time as your 18" unless they are playing completely different frequencies.
You really need to decide where your current problem lies at the moment. Are you missing midbass?
Do your mids/midbass not go low enough or not have enough output for your tastes (and have you tried an EQ to adjust if this is the case)?
Do you want more upper bass output (and can a change in enclosure give you want you want)?

I feel there may be a much better alternative for you to try instead of your current idea.