It is two way communication. What do your devices have?
2.4Ghz? 5Ghz?
Single channel, multi channel?
First thing I would try on yours is switching the channel it is broadcasting on. Generally the default range on routers will be over populated by other consumer grade routers in a neighborhood. Only one device can actually communicate at a time, so if there are several wifi networks in range, that can cause a lot of problems.
Antennae shape can also make a difference on the router. Some are designed for horizontal distance. Others for vertical, and others for more spherical coverage.
I recommend looking at ASUS high end routers. They seemed to do quite well the last time I read through a round up. Netgear Nighthawk are popular...