Australian Idol is toughening up, with producers and judges determined not to let the TV singing show fail like its stablemate Big Brother did.

One judge gone, a new host, different elimination and voting systems, and tougher advice to contestants will be among the changes when the Network Ten series kicks off its sixth series later this month.

It comes as the show is under increasing pressure following a slump in ratings last year and the axing of Ten's other long-running reality show, Big Brother.

The show's ability to produce talent has also been questioned, with last year's winner Natalie Gauci yet to release an album.

Among one of the biggest changes this year, veteran judge Mark Holden is gone - leaving Kyle Sandilands, Marcia Hines and Ian 'Dicko' Dickson holding the fort and vowing to be very tough on contestants.

Sandilands has said he will tell pudgy contestants if they need to lose weight, and even Hines, who usually takes the soft approach, will come down hard on arrogant contestants.

Australian Idol's executive producer Stephen Tate says Hines particularly, is more "forthright" this year.

"Marcia can fire up if she sees any form of arrogance or a lack of ambition or lack of work ethic," Tate told AAP, adding that she hadn't been under any direction to do so.

"Those are the sorts of things when people are wasting an opportunity it really annoys her and there's probably been more of those than in previous years."

In one episode, Dicko has some scathing comments for a contestant who says he isn't too fazed about winning.

All three judges boot him despite having flagged him for the top 24.

Hines says she's looking for a balance.

"It's great to see someone that's ambitious but not ravenous," Hines told AAP.

Former contestant Ricky Lee Coulter joins Andrew G and James Mathison hosting.

Her job is to mentor and give advice to contestants backstage.

Coulter says she understands the highs and lows and can give advice when contestants are "freaking out".

"I spend a lot of time with the contestants, talk to their families, talk to them before and after they perform," Coulter told AAP.

"I'm there as a shoulder to cry on when they're upset, when they're angry. I'm there to jump around with them and be excited."

Comfort is something they will need, as Coulter knows the competition is harder this year.

"They're putting the pressure on having to step up to the plate and really deliver, and earlier," Coulter said.

"The last couple of years the contestants have been cottoning on to what's going to happen where... this year they're changing it 100 per cent."

Among other changes, producers have vamped up the usually dull earlier rounds by giving contestants a band and audience to sing with.

Monday night elimination rounds will also be altered to allow voting to be reopened once the bottom three are announced.

Tate believes it will be more fair and help avoid the situation Coulter found herself in four years ago when she was booted out surprisingly early.

"We're going now going to be in a position to reveal who's in jeopardy and let the audience make an informed decision," he said.

"It'll certainly mean that Australia gets to keep their favourite singers."

While the winner will win a lucrative recording deal, Tate says the prize will be boosted this year - details will be announced in the next month.

Judges and producers believe they've found the most talented group ever in the competition that in previous years produced stars like Shannon Noll, Anthony Callea, Paulini and Guy Sebastian.

It comes after this year's auditions were also open to Aussie expats living in London.

"Every year you're terrified that you're not going to get enough people turn up," Tate said.

"So it was very satisfying to see year-on-year growth in the audition crew and certainly the quality is amazing."

Coulter agrees: "The quality and depth talent, this is the strongest group of 100 singers we've ever had," Coulter said.

"This year they've gone all-out to make sure everyone is exceptional.

"Not just good, amazing.

"I'm almost jealous that I'm not in this year."

Hines said she was blown away by how young the top 100 contestants were this year, while Sandilands said he noticed that there were a lot of more "left of field artists".

As for conflict between the judges, Sandilands says viewers can expect fireworks, especially between him and Dicko.

"He's an old man ... I'm a bit more open to something new and different, and he isn't," Sandilands told AAP.

Hines says the dynamic works well.

"I actually like the guys, contrary to what you read," Hines said.

"We disagree, but it all depends on how far I want to take it."

TV expert Vincent O'Donnell from Melbourne's RMIT University says the judges being stern should work well with the audience.

"It's the stridency of some of the critiques from the judges I think has made it rate well," O'Donnell told AAP.

"It's really an old fashioned talent contest plus abrasive judges."

He said it was difficult to compare it to Big Brother because they were quite different, Big Brother a "voyeuristic show" and Idol a "talent contest".

Tate is confident about the show this year saying he isn't worried by Big Brother's downfall, because they get compared to shows every year.

"When it wasn't Big Brother that had finished in the first year it was other shows that we tried," Tate said.

"You go into every new series as it's potentially the last so you do everything you possibly can to make sure that it's the best possible show it can be."

Sandilands, who hosted Big Brother and was accused of being responsible for its failure, says he's not worried at all because he knew Big Brother was on its way out.

Hines believes Idol will be a success because people love watching a "feel good" show that the whole family enjoys.

"You watch someone blossom," she said.

Australian Idol starts on Sunday, August 24, at 7.30pm.