Does your bass has vibe? Box in the mix and on it’s own, does it have personality? Well if the bassist is boring that probably doesn’t matter, they can just add some extra low end informations. However if the bassist is actually doing something interesting, then you wanna chase that vibe. I’ve noticed that the vibe comes more from the actual instrument itself and the player, than from the amp or the processing. Those may enhance vibe, but won’t had it to you. Below are two videos by Snout, featuring Ross McLennan on bass. Playing basses with more personanility in them than most singers.

Sometimes bassists will be very attached to certain bass. Often one that is nice to play, not one that sounds really distinct. Also knowing whether the bassist you are working with can play with a pick or only fingers or visa verse. Either have listen to these songs, you’ll get what I mean.