DJM 900 Nxs2 takes effect of the channel that is not playing

I'm a dj that uses a lot of echo and post fader effect. So i would like to do a 1/1 echo effect out on the current playing song. but when i choose the right channel on my DJM 900 nxs 2 mixer it takes the auto bpm speed of the song that is not playing. i mix with song that vary a lot on bpm so my echo was all over the place.

Is there a way to setup my mixer to auto take the bpm speed of the current playing song (when selected the right channel). 

I hope that this is clear enough let me know if someone needs any additional information.