'''Was it always this way''' or did you recently upgrade to Mavericks or Yosemite ''(lots of known wireless issues with those OS builds)''.
Further slow network issues can sometimes be:
* an ISP issue,
* grabbing onto someone else's new open home network,
* a new home network running on the same channel as yours.
* P2P sharing (iTunes music, iPhotos, doing cloud backups, streaming video to a TV) can also slow a network.
Try checking the network ID your using, try chaining your wireless setup.
''If this answer is acceptable '''please remember to return and mark it accepted'''.''