"The Big Day Out is home," reads a sign below an oversized blow-up of Humphrey B. Bear on the Causeway. For a while there, the festival juggernaut was not so assured.

Plans for tomorrow's instalment of the Big Day Out were in limbo for almost two months after sound restrictions and financial pressures forced organisers to downsize and move from Claremont Showground.

After weeks of grappling, the much smaller McCallum Park site in Victoria Park, overlooking the Swan River, was chosen.

As workers set up the single main stage - instead of the usual two - local promoter Ken Knight said he expected about 15,000 people, well down on about 35,000 people last year.

"It's a beautiful site," Mr Knight said. "I think the fans will really enjoy it."

Seattle grunge rockers Soundgarden will headline this year's festival after Chicago rapper Kanye West was pulled from the line-up because of the downsized Perth leg.

Perth's Brow Horn Orchestra will play their first Big Day Out and singer/songwriter Nick Owen said the event still had appeal. "It feels like you've made it once you play the Big Day Out," he said.

It is the fourth time the festival has been moved since 1993, when punk legend Iggy Pop enthralled the crowd at Fremantle Oval. It also had stints at Perth Oval and Bassendean.