benny beatz said:
listen to pieces of music, mentally isolating each instrument...
this is something i was doing a long time before i started producing music. it has helped me enormously.
Frankie, your question has obviously been interpreted in two very different ways. you really need to be more specific with the wording of your question.
everyone 'hears' music, but very few people actually 'listen' to music. actually listening and concentrating on individual elements in a song. this is something you shoud try, even if its not what your question was aiming for. listen to some of your favourite songs with a set of head phones, this way you will be able to create a better visualisation in your mind of the sound you are trying to isolate. in your case it will be the bass. isolate the bassline in your mind, concentrate on it and try to ignore everything else that is going on in the song, particularly the singer or rapper. just listening like this will help enormously to understand where and how notes and sounds change, and how they fit into an overall track.
my advice on fruityloops is: your not going to find too many high quality bass "sounds" in a standard/stock version of Fruityloops straight out of the box. judging by the nature of your question, 'equalizing' and 'effecting' any of the existing preset bass sounds, productively, is probably beyond your capabilities, at this stage...but this is where you can learn a lot..
the best thing to do is muck around with the 'boobass' sound that a few people have mentioned. play around with all the knobs, dials, switches, buttons and anything else you can press, push, turn, twist or slide, with the mouse or keybaord. never mind how complex it all looks or how crowded the screen gets, its not like you can break the program.
the idea of this is to experiment and explore the program. eventually you will stumble across effects that you like and you will get to understand how certain knobs and buttons affect a sound. but also try and read up on some of the technical terms or labels that on or below the knobs in fruityloops plugins & instruments. find out what they mean. look them up on the net, there will lots of resources for this kind of info.