adding another cable box

can I just go to the cox office get a box and connect it myself?

Oded,

The purpose of the Cox TV Support Forum is to allow customers to discuss technical topics related to residential Cox Cable Television services with other customers. If you need help with billing or other account specific issues, or would like to submit a channel request, please reach us on Twitter at @CoxHelp, visit us on Facebook, or by email at cox.help@cox.com.

The ability to pick up a box at the Solutions Store depends upon your subscription. Please email cox.help@cox.com or reach us on social media with the following to allow us to look at this for you.

Your complete address including city and state
The account holder's name if different from yours
The Cox PIN or last 4 digits of the account holder's Social.

Since your inquiry is account specific and another customer would not be able to definitively assist, your post will be locked.