At least di na ako worried because everytime i ask google i always end up with negative answers
Like this one on my same situation
http://www.hometheaterforum.com/topic/316198-addingreplacing-htib-sub-help/
tama naman first reply doon sa thread, in fact it's the gist of what everyone else is saying here.
I don't see any reason that would not work. If I were you though I would take the sub woofer out wire from the receiver and make a "Y" . Basically splice the one wire into two so you can connect a split to each of your high level inputs (Red & Black screw terminals) on your sub. If you just connect one you will only be using half of the sub woofer's amplifier. It should totally work.
yung mga kumokontra doon nagmamagaling lang pero hindi naman talaga nakakaintindi.
As to your planned setup huwag mo na i-split, you can just cut the wires near the passive sub then connect to the svs high level input. It would be simpler and sound better.
Just make sure to leave enough length of wire at the passive sub for future reconnection. Positive wire must be shorter by about an inch than the negative wire or vice versa, it doesn't really matter. Different cut length will serve two purposes: to minimize shorts and as guide for easier reconnection when needed.
Simple crude diagram
+ from amp -------------------- cut ---------- + passive sub
- from amp ---------- cut -------------------- - passive sub
then
+ from amp -------------------- svs high level input red
- from amp ---------- svs high level input black
Positive is usually the wire with stripe pero wala naman kaso kahit magkabaligtad kasi may phase control naman ang svs mo.