Is bi amping worth it ?

If done right, which an active crossover and the right amplification yes definitely.  But if all you plan on doing is using two amps and using the passive crossover inside your speakers, then probably not.

@hardhattg 

I'm not sure what you will accomplish after looking back to your original post. I would need 4 mono amps to do what I'm doing with mine. I don't see how yours would be any different. I use two stereo amps and use vertical bi-amping. It makes a huge difference with my speakers. As I said before, I would never go back to a single amp and I don't think that I would change that opinion even if I did have two hefty mono blocks or a single high end stereo or dual mono amp. I could be wrong but in my system, what i have done serves me the best. You may find completely different results in yours but if you are unsatisfied with your bass response, you owe it to yourself to try it........or at least try something different. Best of luck.

OP:  

I jumped into the discussion about biamping without reading your original text. I think it is smart to step back from purchasing a subwoofer without fully understanding the implications.  

I'm not sure bi-amping will give you enogh benefit, but it's not a zero gain solution either.

An intermediate and often overlooked approach is to improve room acoustics. An overly reflective room will "lack bass."  The real issue isn't that there's not enough bass but that the mid-treble stays around too long and raises our perception of mid-treble output. 

If you decide to keep your system as it is... One option is a  JL Audio CR-1 Crossover.  I recently purchased a used one and it has provided much improved transition between the mains and the active subs.  I am sure there are better ones (even digital).  The adjustments for the mains and subs are very helpful.  I was patient in looking for a used one and found it for $1850 recently.  Full box/looked brand new.  Just a thought.  Have fun! 

If I am not mistaken it seems that at the very least , that bi amping my khorns , using one mono block for both low frequency , woofers in both speakers and the other mono block for the midrange and tweeters in both speakers . That should give me the ability on certain music to increase power to the low frequency amp if I desire to ?  I believe this is correct and may be all I need.   Will find out this weekend hopefully.    I am not looking for a big change I am quite happy with the system and I love the sensitivity of the horns  , always have but just feel like could use a touch more low end from time to time.