i have two cabs: one peavey 3620(2X18's and 2X10's) and one peavey 410T(4x10's). the 3620 is rather large and unwieldy... and both together looks kinda funny, one short and one tall. i would like to build two identical cabs that each have 3x10's and 1X18. maybe a "folded horn" or "tuba" or "sub" design for the 18 on the bottom and the three tens on top. i think i want each ten to be in its own little enclosure inside the top "half". sounds good in my head but i don't know enough about speaker design and what not to build a "tuned" cab. where can i go to get the info i need?