Simon Cowell left his fellow judges Louis Walsh and Nicole Scherzinger to launch the next series of The X Factor on their own.
Show boss Simon missed the event at a central London hotel to focus on America's Got Talent.
And returning judge Sharon Osbourne was also absent, due to "filming commitments".
The ITV singing programme returns for its 13th series on Saturday night.
Last year's show, featuring Rita Ora, DJ Nick Grimshaw, Cheryl Fernandez-Versini and Simon, fell flat - and was even beaten by Countryfile in the ratings - leading to a shake-up.
Long-time presenter Dermot O'Leary is also returning to this year's series.
Simom previously handed presenting duties to Caroline Flack and Olly Murs, but it was Olly's gaffes that made the headlines.
This year, auditions are taking place in small rooms instead of on stage.
In the forthcoming series, viewers can expect acts including a "living doll" and a woman who stormed into the audition room uninvited.
Nicole, who is making her return to the panel, has defended the judging line-up against criticism that it is "too old".
The former Pussycat Dolls star, who pulled out of Cats on Broadway to join the show, is the youngest judge at 38.
Nicole, who was partly responsible for the formation of boy band One Direction, has confirmed she will perform during the new series.
Rylan Clark-Neal and Matt Edmondson will be hosting a new-look spin-off show, The Xtra Factor Live.
Formerly The Xtra Factor, this year's companion programme - which airs on ITV2 after each episode - will be live for the first time.
They are taking over from last year's presenters Rochelle Humes and Melvin Odoom for the revitalised show.
The duo will be joined in the studio by contestants who have appeared on the preceding main show, as well as a panel of celebrity guests, to share their thoughts along with the audience and viewers at home, via social media.