Boro have slipped to 15th in npower League One after Tuesday night's 1-0 defeat at Scunthorpe made it five successive losses.
And Smith, whose side face a home meeting with Colchester on Saturday, said: "We are in a place we don't want to be.
"There is nothing wrong with the spirit or effort of the team, but at the moment the quality is missing.
"It's not just the fans who are disappointed with the way results have been going for us, so too are the players.
"The only thing we can do is work hard on the training ground to turn things round."