How difficult and expensive would it be to build a sub?
Can a bridged stereo amp be used to power a sub, or power two subs? I read reviews of some of the amps on audioreview and seems lot of people are using such amps to drive passive subs.
How difficult/ expensive then would it be to build a passive sub?
you will be better off using 3 CHT 12s rather than 2 CHT 15s
this is a never ending chase. For the same budget, 2 subs MAY give better room response, but in the similar budget you WILL get much better next level sub if you go for single.
Same logic extends for 3 better than 2.
The Cht 15 is arnd 70-75
But b4 you do that what is your room size & rest of the set up again?
All the best
Regarding sub-woofers, i wonder if it applies..
to choose 2 or 3 average looking girl-friends
or to choose one stunner.
you get easily bored by one stunner girl after a while but if you have average 2 or 4 or 8 girls then every one has their own taste so you never get bored and everyday you have different flavor
that's what i think