Walls. Proximity to walls is the single biggest factor. Both for the speakers as well as for you. Speakers back against a wall and near the floor with you sitting near a wall, that's about as much bass as you're ever gonna get. Usually people prefer to move them around trying to get smooth and even, and for that it helps to bring things out into the room more.
Another thing, what I described is very general. But bass isn't one thing its a range and a room isn't one thing either there's different shapes. It may be you are sitting in an area of suckout or cancellation. So try listening closer or further away if you can and see what that does.
Another thing, what I described is very general. But bass isn't one thing its a range and a room isn't one thing either there's different shapes. It may be you are sitting in an area of suckout or cancellation. So try listening closer or further away if you can and see what that does.