MUSIC / CHRIS PASLES : Sound Advice on Pacific Symphony Changes : Acoustics are altered, string basses and some horns are moved, giving better balance to the orchestra, says music director Carl St. Clair.

Anyone who attended Pacific Symphony subscription concerts recently at the Orange County Performing Arts Center had to notice two things immediately. First, all the string basses had been moved to risers fanned across the back of the stage; second, the sound of the orchestra was markedly improved.

“I’d known there were things I hadn’t been hearing on stage,” Pacific Symphony music director Carl St. Clair said in a recent interview at his home in Turtle Rock, where he discussed his dramatic physical reorganization of the orchestra.

“Things that I needed to be feeling and things that the musicians needed to hear weren’t making a strong enough sonic presence. And that’s namely the low-string side of the orchestra.

“Believe me, I don’t mean to be saying all of this is to be blamed on the hall, because it’s a matter of working with the acoustic environment that you live in,” said St. Clair, 39, who took over as the Pacific’s music director in 1990.

“To get everybody (who uses Segerstrom Hall) an immediate, present sound, they had to build an acoustic environment which was very immediate and very present and very fast, which then tends to make the high end of the orchestra very bright and very quick and very crisp. And in return, the low side of the orchestra has some difficulty being heard.”

To address these problems, Center officials, at their own expense, brought St. Clair together with Gerald Hyde, one of the original team of acousticians who designed the building.

Hyde sat in different parts of Segerstrom Hall during a rehearsal to report back, St. Clair said, “on what he was able to hear, what he wasn’t able to hear and what he thought he should be hearing that he wasn’t.”

The resulting changes were extensive, although not everything was as obvious as the relocation of the basses.

Overhead retractable sound baffles were reconfigured. “I didn’t realize the panels on the ceiling could be adjusted,” St. Clair said. “And there were big curtains somewhere up in the roof that were opened up.”

On Hyde’s advice, St. Clair also moved the trumpets and trombones to sit in line in front of basses and then “stacked the horns in the Germanic style”--on his right hand as he faces the orchestra.

“From that first rehearsal to the second dress rehearsal, there was an amazing difference,” the conductor said.

“Orchestra members were able to hear the basses more. For the first time, they had an impact. When they played a pizzicato or something--boom! It was there. It had a rhythmical influence. It was not just something that was in the underground, moping around . . . .

“Secondly, it gave an overall balance to the orchestra which we hadn’t felt before. It was a larger, deeper and darker sound.”

Still, to accommodate the chorus needed for Ravel’s “L’Enfant et les Sortileges,” to be played today and Thursday, the basses will be moved temporarily back to their former position at St. Clair’s right hand.

But for regular orchestral concerts, St. Clair left no doubt that he wants to keep the changes.

“Yes,” he said. “Until there proves to be a better solution, we’re going to keep working with this one.

“Look, we’re making that place our home. I need to feel that it’s a home where I can move the furniture around.”

Despite numerous changes, St. Clair does not consider his work done. At the orchestra’s most recent concert, for instance, the string section still sounded a bit thin and edgy.

“That’s a point well taken,” he said. “It’s something that we’ve worked on, and it’s something that I feel is getting better.

“A lot of it has to do with the immediacy of the sound coming off the stage, because that’s the way it was built.”

But there are other factors than the physical attributes of the building, St. Clair said.

“A large part of (the strings’) playing diet is in-studio playing. If you ever go to a movie and concentrate on the string sound in it, you hear it’s a very lean, very crystalline, very clear type of sound.

“It’s almost a non-vibrato type sound because this makes for much more tension or effect in a movie. And also, so much of what goes on in a movie studio is also dabbled with later. Of course, we have been talking about all of those elements.. . . .

“The positive thing is that there are no problems that we have that are without very optimistic, positive solutions. We have only positive things ahead of us.

“But any orchestra must grow like a tree-- slowly. Where there is any new music director, there is a great onslaught of energy. But when all the dust settles, you know and I know that orchestras that have extreme quality and merit are grown slowly.”

* Carl St. Clair conducts the Pacific Symphony, the Pacific Chorale, the Pacific Chorale’s Children’s Chorus and members of the Los Angeles Music Center Opera in Ravel’s “L’Enfant et les Sortileges” today and Thursday at 8 p.m. at the Orange County Performing Arts Center, 600 Town Center Drive, Costa Mesa. Music from Tchaikovsky’s “Nutcracker” ballet will complete the program. $12 to $36. (714) 556-2787.

NEW CHAMBER SERIES: In a pilot program modeled upon the “Chamber Music in Historic Sites” series created by the Da Camera Society in Los Angeles, the Laguna Chamber Music Society and the Orange County Philharmonic Society will present the Prism Quartet on May 18 at 8 p.m. at the Laguna Art Museum in Laguna Beach.

Quartet members Reginald Borik, Michael Whitcombe, Matthew Levy and Timothy Miller will play an assortment of saxophones and electronic wind instruments. Their program will include classical music transcriptions and contemporary works, including the first Orange County performance of Michael Ruszczynski’s “Fantasy Quartet.”

The work will receive its premiere on May 17 at the Pasadena Police Building and Jail in a Da Camera-sponsored concert, and will be played again in February in New York under the auspices of the Chamber Music Society of Lincoln Center.

Founded in 1984, Prism will be the first saxophone quartet presented by the Lincoln Center society. Tickets: $10. ($5 for students and senior citizens.) Information: (714) 646-6277.