Central to the city’s downtown cultural district, the Santa Barbara Center for the Performing Arts is home to the historic 1,550-seat Granada Theatre. Recently equipped with a digital cinema system and 30-ft screen, A/V integrator AMT Systems was called on to provide a supporting 5.1-channel audio system.
‘We installed EAW QX596i three-way, bi-amped boxes for left, centre and right, and two EAW SB2001 subwoofers,’ says AMT Systems Senior Systems Engineer, Mike Shelton.
Because the new system uses a Christie Digital Systems rear projector, the left and right channel speakers are flown to either side of the Stewart screen, while the centre channel speaker and dual subwoofers were suspended immediately above the screen. Two Powersoft K2 DSP+AESOP amplifiers power the high- and mid-frequency drivers in the three QX596i cabinets, while three K3 DSP+AESOP amplifiers drive the four 12-inch low frequency speakers in each box. Two K10 DSP+AESOP amps power the twin SB2001 dual-21-inch subwoofers, which carry the low frequency effects (LFE) channel.
‘A Dolby Labs CP750 digital cinema processor is taking all the audio from the Doremi Labs ShowVault video server and decoding it out to the 5.1 channels,’ Shelton says. The LCR and LFE channels are distributed to the Powersoft amplifiers, while the left and right surround channels are sent to the theatre’s previously installed Meyer Sound Constellation system. ‘The high slew rate and tremendous power capacity gave the speaker system remarkable impact and effortless dynamic range. The Powersoft amplifiers that we used provided all of the DSP we needed to tune the speakers, set the crossovers and get the room flat. That made it really simple to do the X Curve processing in the Dolby processor.’
The X Curve, an ISO and SMPTE standard, was developed to normalise motion picture audio playback. ‘If you take the Dolby processor out of the signal chain the room is tuned to be flat through the amplifier processing,’ Shelton explains. ‘We do the cinema-specific tailoring in the cinema processor with two different presets. One is set up for the X Curve; that’s your typical cinema EQ. Then we have another preset that is for material that wasn’t mastered for cinema release; that’s a more natural EQ curve.’
‘When we delivered the amps I built a preset group that included all the EAW GrayBox setting for every possible combination of speaker loads and installed them into each of the amps,’ says Paul Hugo of Marshank Sales, Powersoft’s regional agent. ‘When Mike installed the amps, he just went to the menu of presets and selected the appropriate one for each individual channel. And since every channel has every preset there is redundancy built in should there ever be a failure – which, of course, will never happen…’
The installation marks the five-year anniversary of the Granada Theatre’s reopening following a US$50m restoration and expansion, including technical enhancements and acoustical improvements. Built in the 1920s, the Moorish-style theatre is home to a variety of performing arts companies, including Opera Santa Barbara, Santa Barbara Symphony, CAMA, State Street Ballet and Santa Barbara Choral Society. Kyle Ridenour of acoustical and audio-visual/IT consultancy McKay Conant & Hoover was the consultant on the project. NEP’s American Hi Definition division supplied the Digital Cinema projector and screen.
More: www.powersoft-audio.com
