Smh news: view from the V- elevator of soundwave music festival. Photo Dean Sewell. 24/2/13

Early thrills … more than 70,000 were expected. Photo: Dean Sewell

COULD it be that heavy metal fans, for all their bluster, head-to-toe black clothing and growling along to demonic lyrics are just a bunch of big softies?

It's not quite what you expect from fans of bands with names such as Anthrax, Killswitch Engage, Gallows and Cancer Bats, but fans at the heavy rock festival Soundwave at ANZ Stadium on Sunday reported a much friendlier and more respectful atmosphere than at many other big gigs and festivals.

Sarah, Jemima, Chelsea and Karina, four young women from the western suburbs, said they felt safer at Soundwave, which was expected to exceed 70,000 by the time headliner Metallica hit the stage at 8pm.

Aerial view from V elevator. Photo by Dean Sewell. SMH News. Sunday 24th

Nation's biggest music festival ... more than 70 bands played across nine stages and organisers sold out all five national shows, a total of 270,000 tickets. Photo: Dean Sewell

''It's better for girls at heavy shows than it is at a pop show,'' said Chelsea, 21. ''If the music starts getting really heavy, guys start to look around to make sure we are all right.

''I went to the Veronicas when I was 16 and it could not have been a more ruthless situation.''

Sarah, 22, said: ''Metal people are happy people.''

Kye Disson, 35, from Enmore, who has attended gigs across most musical genres for nearly 20 years, said ''look after each other is the metal ethos''.

That spirit extended to the acts on the main stage. The lead singer of US rock group Linkin Park, Chester Bennington, stopped their set out of concern for a fan who had fallen in the mosh pit, refusing to continue until he had ''the thumbs up'' they were OK.

Eric ''Bobo'' Correa, the percussionist with hip-hop group Cypress Hill, said: ''The way the people look out for each other, it is a bit different … the music is aggressive but that doesn't mean that they are aggressive.''

The Big Day Out's organisers must be looking on in envy at Soundwave - organisers managed to sell out all five national shows, with a total of 270,000 tickets, putting it ahead of the Big Day Out as the nation's biggest music festival.

Soundwave opened in Brisbane to 50,000 fans on Saturday. The festival moves to Melbourne on Friday, with shows to follow in Adelaide and Perth.

More than 70 bands played across nine stages at the steamy Homebush sites on Sunday, with thrash metal veterans Anthrax, Stone Sour - which features Corey Taylor and Jim Root from masked metal act Slipknot - and Cypress Hill providing most of the early thrills.

In all, the event's mostly American headliners have sold more than 250 million albums.