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If your bed is close enough to the wall that you are to close to the rear channel, I would think about mounting that one higher on the wall so that there is some distance between it and you. It may be to distracting otherwise. when you can get a good distance there, you can just mount the others at a height (1' or 2' higher) that is not to close at ear level while sitting, or lying down whichever you prefer. Try to keep the height of the rear and the other speakers distance no more than a couple feet different. Those go in the middle of the room or as close as possible. You could also try setting the speakers on something to prop them up kinda at different heights maybe using boxes or books etc, then see what height sounds best from both the bed and another listening area. The front ones go at the same height but try to keep them closer to the center of the room just next to your display. The center should go either above or bellow it depending on your personal opinion of what sounds and looks the best. There is helpful info on that on this forum.
When you mount them try to use studs in the wall for better support and you may want to consider something like felt behind them to listen the vibrations if you are not using mounts that extend several inches from the wall. If you own your place, there is more you can get done or perhaps do in the future to make things more functional or look nicer.