Need help with my set up

[yellowblanket]

Ok, my Home theater is in my basement. At the time the sound is decent but i can't help but noticed that the basement is just too big for the speaker to take advantage of.
As you can see from the pic, i wanted to put a dry wall/insulation right across (the hightlight part will be drywall) And i was wondering if this will help the sound from bouncing off better.


the lenght of the whole basement (from front speaker to the back) is 26 foots. I am basically putting a wall there to cut it back to 13 foots. Is this a wise idea? The only draw back i can see is that i can't watch movie while playing pool.
Any professional advice will be much appriciated =)