Time-Warped in Heat of the Day : Pop music review: The 15-band festival might have been better served by stronger acts playing longer and redundant din dropped.

About the only thing harder to find than a shady spot at Irvine Meadows on Monday afternoon during the Warped Tour festival was subtlety, particularly during the marathon first half of the punk-centered show. Throughout this final stop on the 25-city tour, guitars sizzled, singers howled and a core of fearless fans moshed in the pits with reckless abandon.

From two stages bookending the Concourse Concession Circle, bands performed alternating 30-minute sets while vendors hawked their goods and pro skateboarders strutted their stuff on temporary ramps. A 50-foot climbing wall was erected for fans to scale at no charge.

Musically, the eight-hour, 15-band marathon offered a mixed bag, with local and national punk and hard-core acts. At its best, the melange of talent was engrossing and compelling. A handful of rote performances, however, suggested that sunbaked fans would have been better served with a scaled-down lineup of eight or 10 solid bands--each allotted more than half an hour on stage.

Such established hard-core bands as CIV, Wizo, Good Riddance, Orange 9mm and Sick of It All delivered a recycled, in-your-face din of noisy thrash devoid of imagination.

Their grinding, at times grating, adherence to the hard-core formula wore thin. It went something like this: Project a hyperactive stage presence, enlist at least one dreadlocked musician, plus a guitarist who bangs out three chords, then encourage the already throbbing mob to press even closer to the stage.

Nonetheless, several other hard-core acts hit the mark by adding just enough color and conviction in forging their own musical personas. Of these, San Diego’s Fluf and Sacramento’s Deftones gave the strongest impression.

*

After touring for years, the Deftones have released a debut album, aptly titled “Adrenaline.” Drawing heavily from it on stage, the quartet created moody, atmospheric soundscapes with swirling undercurrents.

Driven home by the guttural howl of singer Chino Moreno and the angular guitar leads of Stephan Carpenter, such songs as “Bored” and “Lifter” typified a style eschewing speed in favor of a slow-burning, emotional catharsis.

Blossoming live, Fluf was one of the day’s first acts to bring catchy melodies to the mix. After the thrash-heavy “Nirvana, Brass Ring” and pounding “Degrader,” the power trio shifted gears for a pair of crowd-pleasing pop-rock tunes and the bluesy “Got Everything.”

And, unlike many live hard-core bands, Fluf has a front man, O (a.k.a. Otis Barthoulameu,) who sings with restraint, letting themes of self-esteem, perseverance and romantic longing to rise above the instrumental barrage.

New York’s Quicksand, another purveyor of the early East Coast hard-core style, unleashed an exhausting yet impressive set of Husker Du-inspired speed and aggression. Led by vocalist Walter Schreifels, the foursome generally played it hard and fast, downshifting only for the mid-tempo “Delusional” and “Thorn in My Side.”

And, despite neglecting to play two of their strongest tracks (“Skinny” and “Landmine Spring”), the band’s intense set soared on the stinging but economical guitar riffs of Tom Capone, whose tasty jam at the end of “Simpleton” caught fire and threatened to explode.

Of the top-billed, main-stage acts, L.A. punk goddesses L7 were somehow the most riveting and the most playful. The all-female quartet rocked hard on a bed of distortion and feedback emanating from the dual-guitar frenzy of Donita Sparks and Suzi Gardner. Hard-edged songs such as the Black Sabbath-sounding “Talkbox” tangibly reverberated from their sheer aggression.

But L7 has an alter ego too. A spontaneously loose character lurks in the shadows, sneaking into the light to play catchy pop-rock (“Pretend We’re Dead,” “Andres”) or to unveil a winning sense of humor (“At times, we’ve called this tour ‘Spinal Warp,’ “joked bassist Jennifer Finch).

For this, some of the longtime faithful have cried, “Sellout!” But on balance, L7 is wonderfully multidimensional. They’re tough but tender, angry but funny and intelligent, remaining uncompromising in elucidating their personal convictions (which range from pro-choice to anti-war to support of animal rights).

Local fave No Doubt, which plays a likable hybrid of dance-ska-funk-rock, drew the largest and most enthusiastic crowd, which a concert spokesman said peaked around 3,500.

Lead singer Gwen Stefani was an appealing presence with her friendly, free-spirited demeanor--not to mention her attire of a pink and black bikini top and tan jeans, with her blond hair up in a bun--in stark contrast with the stoical stance of male counterparts who had taken the same stage earlier.

Mostly dance-inducing and void of self-importance, No Doubt’s set possessed a wide-ranging subtext of themes such as addiction, hope, romance, lust and food. Invigorated by a tasty, three-piece horn section, the Anaheim-based band connected with numerous selections, including the bouncy “Open the Gate,” the crowd-pleasing “Total Hate ‘95,” the autobiographical plea of “Let’s Get Back” and a preview of the new “Just a Girl,” which can be heard on the group’s next album, “Tragic Kingdom,” due in October.

*

Main-stage headliner Sublime brought the long day to a close as the sun set. The Long Beach trio’s awkward set of quirky reggae, rap and rock was not one of its best.

Lead singer-guitarist Brad Nowell usually stands apart because of his soulful singing. But on this day, he rushed through a sloppy, choppy performance, apparently distracted by some unruly moshers and a roving, intrusive video camera.

Sublime did recover, locking into some infectious reggae grooves that made for a strong closing. But by then, much of the weary crowd was drifting toward the exits.