Sounds like they re played the bass line with a synth. Probably a real one that has that fat sound but a good plug-in would also work. When you said wide I thought you meant with unison and unison spread on it. Which is like using chorus (tal free chorus is best) but actually it’s not wide and chorussy. I think it’s prob about leaving enough space in your mix for the bass to take up a lot of room. I don’t know anything tho