My Behringer Feedback Destroyer arrived today but before I use it I have to find the best place to position the sub. I have make test tones from here:

http://www.snapbug.ws/sinewaves/

My sub is the Dayton 10" that I bought for $99. from Parts Express. I'm having some difficulty finding a place that the sub will have a decent response curve before EQ. I'm curious to know if the response curve would be much different with different subs. I do plan to upgrade the sub at some point but I'd like to keep the Dayton for now. My next purchase will be the 340C and then I want to upgrade my two channel system in my study before the new sub.
I know a number of you have gone to better subs. Did you keep the same location and were there different response curves (non-EQ'ed).

Thanks,
David