If you want to enable (or disable) the '3 mic' feature in your premium room, do this...

Log into www.paltalk.com at the top right of the page.  Now click on the 'edit room' link in the 'my room' section.  Now click on the 'premium room settings' selection on the left side of the page.

Now click on the 'edit' button near the top right of the page, then click on the 'Allow up to 3 members to be on the mic simultaneously' selection.

Be sure to click on the 'save' button near the bottom right of the page when you are finished.

You will have to close and re-open you room after doing this if it is currently open.