JAZZ REVIEW : Technical Problems Plague Second Day of Playboy Fest : Many acts sparkle--but they can’t always be heard. The sound of some big draws is reduced to a muddy wash.

Despite one of the most promising lineups in its 15-year history, Sunday’s edition of the Playboy Jazz Festival didn’t really break into its usual all-out party mode until the final act. With a lineup that included a fusion group from Sweden and a big band filled with some of New York’s best journeymen musicians, it took Los Angeles-based conguero Poncho Sanchez and his eight-piece Latin Jazz Band (nine-piece if you count master of ceremonies Bill Cosby’s contributions on cowbell) to break the festivities wide open .

Sanchez, leading the same band that can be seen most weeks in one or another of Southern California’s clubs or concert halls, announced that he was “going to get you all up and dancing.” And sure enough, moments later, the more than 17,000 in attendance at the Hollywood Bowl were up and moving to a cha-cha titled “Cinderella.”

Coming from this unexpected belle of the ball, the title seemed appropriate. The bearded bandleader followed it up with a salsa-paced medley of James Brown numbers that also included bits of Dizzy Gillespie’s “Manteca” and Tito Puente’s “Oye Como Va,” all given the same rhythm-intense treatments.

It wasn’t that the other acts in the 8 1/2-hour program didn’t deliver. It’s just that what they delivered couldn’t always be heard. Plagued with audio difficulties, as was Saturday’s installment, the sound of some of Sunday’s biggest draws--Dr. John’s New Island & Pleasure Club, singer Patti Austin and pianist McCoy Tyner’s big band--was reduced to a muddy wash.

The question posed in innumerable Playboy Advisor columns--does size matter?--was applicable here. Quartets and quintets came across fine, if a little flat. But the larger ensembles were badly balanced, with some instruments overly prominent and others barely visible in the mix.

Up close, the sound was loud, harsh and two-dimensional. In the seats farther back, it was timid and confused. Only somewhere in the middle of the bowl, in the aisle between the boxes and the bleachers, did the audio quality reach some kind of balance.

Despite the sonic problems, there were good, even superb performances throughout the day. Playing a candy-apple red trombone, Nils Landgren from Stockholm kicked things off with back-beat heavy excursions that featured his robust, sometimes surprisingly melodic slide work. At times, the trombonist employed wah-wah effects that recalled Miles Davis’ electric trumpet experiments of the early ‘70s.

Trumpeter Roy Hargrove’s quintet, with its hard driving, post-bop style, made a surprisingly seamless transition from Landgren’s fusion beats. Spurred on by hard-hitting drummer Gregory Hutchinson, the trumpeter pulled from the late Lee Morgan’s bag, applying funky, blues-riddled passages to his solos while playing smooth and pretty during the ballad “September.” Hargrove even took a turn singing the tune’s lyric, a miscalculation that was redeemed only by the fine solo that followed.

Suffering through some of the day’s worst sound, Dr. John, looking hot in black shirt, jacket and beret, gamely played through a set of New Orleans-inspired party tunes and the standard “More Than You Know.” Sadly, John’s playful chordal approach to the keyboard, full of boogie and barrelhouse references, was lost every time his three-piece horn section began to blow.

Somehow, the Zawinul Syndicate can’t help but sound like Weather Report, the group keyboardist Joe Zawinul once led with saxophonist Wayne Shorter. At one point in his set, Zawinul played a wind-controlled synthesizer, an instrument played much like a saxophone, and not surprisingly he came off sounding like Shorter, with much the same tone and note placement. But the Syndicate took a more worldly view than Weather Report did, bringing a wide variety of ethnic influences to its moody, often moving hybrid.

The day’s most musical moments came from saxophonist Charles Lloyd’s quartet. Wielding a more aggressive style than heard on his two recent comeback albums, Lloyd showed expressive mastery over a number of impressionistic backgrounds. His group, with pianist Bobo Stenson, bassist Anders Jormin and drummer Billy Hart, was particularly empathetic.

Tyner’s 15-piece band followed, doing a graceful version of “Angel Eyes” and a passionate rendition of the pianist’s “Fly Like the Wind.” Standouts included tenor saxophonist John Stubblefield’s on-the-edge solos filled with shrieks and caterwauls, and trombonist Frank Lacy’s slippery attack.

From there it was downhill. Vocalist Patti Austin’s set was sullied with feedback and uneven sound. Despite this, she managed to work up some excitement in tandem with guest vocalist James Ingram. Pianist Les McCann and saxophonist Eddie Harris paired to re-create the “Swiss Movement” days of the late ‘60s, but Harris has lost much of his punch. Al Jarreau worked much the same program he’s been doing the last few years. He was at his best, as always, when using his voice as a percussion instrument.

Sanchez closed the show by bringing out his inspiration, Mongo Santamaria, to take a turn on congas, and the revered Afro-Cuban bandleader showed why he is still among the most musical of percussionists. Flutist Dave Valentin was brought out to join the band, but was given only a brief stand.