now this is the easiest way to control how "stereo" a sample is. music can be "mono" or "stereo". stereo being different sounds coming out of 2 different speakers basically. "mono" being there is no difference at all. same exact out of both channels because its only one channel basically.
with this sample, you are going to want it closer to mono, than stereo, because whoever made the sample, panned it all crazy to the left and right. the bass is centered because bass always is. you want it evenly coming out of both speakers. but other sounds you can mess with as far as panning goes.
ok. so to make that sample more mono like, you open the sample to this screen
in the top right where it says fx, change the number to "1"
that sends it to the first "insert" channel in the mixer. now open the mixer.
when the sample is playing, you will see now that the first mixer track as well as the master track should have the levels jumping. the master track is all the sounds that play, while each insert only shows what sounds you sent to that channel. each insert can have sounds assigned the same way. just do 1-2-3 and so on, in that one box in the top right. like my first picture. anyways, those things to the side that i circled in the second image, is where you can put effects on each channel
make sure you click the insert/mixer channel you want to put the effects on, and then click the little arrow in the 1st effects box and find, "fruity stereo enhancer"
now it should look like that^
now in the plugin that pops up, the knob i have circled is what you use to mess with it. moving the knob towards the plus sign accentuates the "stereo" aspect of the sound its processing. meaning it will make the panning more dramatic, while pushing it to the negative side, will make it more mono, if you move it all the way to the negative side it will be completely mono.
as you can see the mixer track 1 is highlighted, i circled that, that goes into the effect, in the effects track 1, which has the stereo enhancer plugin loaded, which applies the effect
this is how all effects work in FL studio. if you want an effect put on your entire song, put it on the MASTER channel. if you just want to put some reverb on a snare, make sure you send the snare to a mixer channel, and just put the effect on that channel
and so on and so on