Well, I was fooling around with my alesis kit and some guitar tones and I notice that I cannot pan anything. When I do it's a slight volume decrease but it's still the same it both speakers. The Tascam has 4 outputs, i've got it set 1/2 and in the reaper master track I have it set for 1/2 Stereo as well. I have also tried doing two mono tracks 1 and 2 and even panning those two L and R and still nothing.
*edit* The Tascam has 4 outputs.... If I set it to 1 - 4 and enable them, then if I pan Right I get no sound, panned left and it's loudest. I know this has to be a simple fix that i'm overlooking.
Found the problem.... it's the 4 channel headphone amp i'm using. Do you think its the cable or the actual headphone amp? (I'm using my speaker cable from my amp currently)... its a Behringer HA400 "Stereo Headphone amp".