pipe - How to concatenate two lines with `sed`?

I am trying to concatenate two lines of iwlist output. My grep and sed commands to remove leading and trailing spaces work fine but I can't get the last sed statement to remove the \n to work. What am I missing?

sudo iwlist wlan0 scanning |
   grep -e ESSID -e Signal |
   sed -e 's/^[ \t]*//;s/[ \t]*$//' |
   sed -e 's/dBm\n/dBm /'

The regex works fine in vim.