San Antonio is a city that prides itself on appreciating the local arts; the city’s museums are havens for visitors seeking to connect with the spirit of the Southwestern adventure. When the time came to develop an area that encompasses bridges across the San Antonio River as part of a 1.5-mile extension of the River Walk, the San Antonio River Foundation realized that sound would play a key role in capturing the essential essence of the region. Eight artists were invited by the Foundation to work on the River Walk extension – dubbed the Museum Reach – that runs from the Municipal Auditorium past the San Antonio Museum of Art/SAMA and to the Pearl Brewery.
A stand-out sonic sculpture located along the River Walk beneath Jones Avenue Bridge near SAMA is Sonic Passage, which features the innovative work of Bill Fontana. A San Francisco-based ambient sound artist, Fontana elected to use a multichannel sound system to project a number of unique sound sculptures that feature recordings from the local area. “I decided to create an audio experience within three separate zones along the River Walk,” the seasoned artist explains, “based on the myriad sound of natural habitats and environments”. The soundscape combines pre-recorded sounds of local wildlife from natural habitats with live sounds captured from the river itself.
“My intention was to create a sound montage of the river for people sauntering along the River Walk,” Fontana continues. “I made a number of recordings of riverboats and local soundscapes, including river eddies and water sounds, in addition to bird sounds recorded in the Gulf of Mexico at the river’s estuary, which is very isolated in the spring and hosts a fabulous collection of birdlife. I made recordings as the estuary came alive from early morning throughout the day, sections of which I used as an evolving sound montage for the River Walk project.” Fontana’s stand-out commissions include Spiraling Echoes, San Francisco, Speeds of Time, London, and Objective Sound, Panoramic Echoes, New York.
“This will be Fontana’s first piece in Texas and one of only a handful of permanent pieces that he has created,” says Mike Addkison, San Antonio River Foundation project director. “He’s using sequenced speakers under Jones Avenue Bridge to produce a blend of continually changing, pre-recorded and live elements sampled from the headwaters of the river down to the Gulf of Mexico. People passing by will hear running water, birds, the turning wheel of an old mill and hundreds of other recordings of the river. In essence, what Fontana is doing is ‘washing’ people in the sounds of the San Antonio River.”
Working closely with Addkison and Big House Sound, a local audio contractor, Fontana developed a playback configuration that includes a hard-disc system to hold the pre-recorded sound elements, linked to a bank of Lab.gruppen C 20:8X modular amplifiers powering an array of Meyer Sound MM-4 miniature wide-range loudspeakers mounted along the River Walk. “The result is a natural sounding experience in a surreal atmosphere,” confides Zack Edwards from Big House Sound, which fabricated and installed the audio system. “The speakers mounted around visitors are divided into three distinct zones: The Canal Area, The Primary Walking Area and a Secondary Walking Area. The sound is fully synchronized to provide an enveloping sequence of sound within each of these zones.”
“I personally selected the Meyer loudspeakers,” Fontana acknowledges,” because of previous experience while designing my soundscape for the Champs-Élysées in Paris.” The original MM-4 miniature loudspeaker was designed specifically for an earlier project in Lyon, France. “In several of my works, I’ve come to rely on the accuracy of Meyer Sound loudspeakers. My medium is sound; I could create the most interesting piece, but if it doesn’t translate to the space, it’s worthless.”
The installer chose a pair of C Series C 20:8X eight-channel amplifiers, which deliver 250 W into four-ohm loads from a 2U chassis. “The C Series is absolutely bulletproof,” Richards considers. “And the amps runs happily in high ambient temperatures without air conditioning, particularly during summer months. We needed a design that can handle wide temperature swings – that was a key selection criterion. Plus the fact that the CX Series’ built-in thermal-protection mode protects the systems against major failures.” The system has been in continual use since it was installed in the spring of 2009, with no loss of operation, the installer reports. “We had a warm summer here in San Antonio, with ambient temperatures of 100F; because of the forced cooling – and shielding from direct sunlight – the inside of the enclosure was maintained consistently at around 90F.”
Lab.gruppen’s C…X amplifiers employ a proprietary Class D output design, with a selectable 35 Hz high-pass filter and built-in GPIO control facilities. “The C 20:8X is capable of adapting to a wide variety of demanding load conditions,” states Richards. Each channel features an individually configurable Voltage Peak Limiter (VPL) that enables the output to be optimized for any loudspeaker load. The system is fully compatible with the firm’s NomadLink network, which allows key amplifier parameters to be displayed via DeviceControl software, with remote control of channel mutes and power on/off under network control.
“It was clear from our initial discussions with Mr. Fontana that he would not compromise on the audio equipment’s quality and performance,” the installer continues. “After that phone call we knew we would be using Lab.gruppen power to drive the MM-4s. We have also started using Lab.gruppen amplifiers for our concert systems, because they sound great and are reliable; it was this kind of performance that we needed for the River Walk project, so the C 20:8X made perfect sense.”
Cables to the 16 Meyer MM-4 loudspeakers – four mounted along the canal, eight beneath the bridge and four along an additional walkway – are carried via ½- or ¾-inch steel conduits. In contrast to conventional low-power 70V, transformer based systems, the MM-4 connects directly to an amplifier and is capable of producing high SPLs with reduced distortion. The loudspeaker houses a single four-inch cone driver with a 16-ohm voice coil mounted in a sealed enclosure; it draws 150W-peak, and produces a reported 112.5 dB peak SPL. The enclosure’s black anodized, extruded aluminum serves as a heat sink to cool the driver’s voice coil. “We specified Belden all-weather outdoor-rated cabling,” Richards says.
As can be imagined, the outdoor installation posed its own unique design challenges. “A major consideration was to protect the systems from weather, theft and vandalism,” the installer confides. “We decided to house all of the playback equipment and amplifier racks in a central, custom-deigned enclosure and run individual signals to each of the suspended loudspeakers,” the installer continues. “The overall design had to cover three primary aspects: 1. The enclosure needed to provide a safe haven for the equipment, safe from public access; 2. It needed to be protected from the elements; and 3. It needed to be temperature controlled.” Fabricated by DDB Unlimited, the rain-proofed enclosure features 19-inch rails for the rack-mounted equipment , plus a venting system that forces air through the hood. “We suspended the enclosure some 12 feet in the air,” Richards recalls, “using custom strapping and brackets.”
The equipment enclosure is mounted beneath the bridge out of the worst of the weather, with conduit routed away from reach of the public. “We used thick-gauge steel for the enclosure, with perforated covers that were custom designed in Austin,” the installer continues. “The Meyer MM-4 loudspeakers are a weatherized version with a water-seal kit and sealed EN3 connector for cable termination. Each loudspeaker is mounted within a 10-by-10-by-eight-inch steel enclosure with a moveable U-bracket yoke and swivel bracket to allow them to be aimed as necessary. Within the river zone the speakers are mounted between 12 and 16 feet above water level, while in the sidewalk areas they are between eight and 10 feet in the air. It is a very robust and well-engineered system.”
The system’s front end comprises a Richmond Sound Design AudioBox AB64 system, capable of providing level adjustment and EQ of 16 discrete channels of audio routed to eight outputs; a fully loaded unit accommodates 64 I/Os. An industrial-grade Windows-based PC handles cross-point programming and replay of pre-recorded audio tracks stored on an internal hard drive. “In addition to the 16 discrete loudspeaker channels,” Richards continues, “we provided eight input channels that handle live sources, which includes a pair of DPA 8011 hydrophones placed in the nearby canal.” The hydrophones pick up the sounds of passing boats and propellers and blend these ambient water-borne sounds with the pre-recorded audio tracks. Microphone pre-amps and phantom power for these live sound sources is handled by a rack mount Whirlwind Mix 5S four-channel stereo console.
The playback system is fully sequenced by the artist to provide a continuously changing soundscape along the walkways. According to Richards, the system turns on at 7:00 AM and off at 11:00 PM. “I like the built-in contact-closure input on the CX Series, which allows the amplifier to be tied directly into an AC power sequencer for powering the amp on and off; this feature can save a lot of money and makes the installation a lot cleaner. For the River Walk project, we used a Lowell four- step sequencer that was triggered by the city’s network clock so that all the gear is safely powered on and off daily.” The time-controlled unit initiates pre-determined start-up and shut-down sequences.
To allow Fontana to remotely access the AB64 while programming and adjusting EQ for the three sound zones from his laptop, Big House Sound installed a wireless network. “This wireless connection enabled the AB64 and associated equipment to be controlled without opening the rack,” Richards explains. “Bill Fontana was really excited about this setup since it allowed him to roam around while making adjustments to the replay sequence and zone levels.”
“The result is a major success,” concedes San Antonio River Foundation’s Addkison. “Our intention was to take sound and bring it into the forefront of the river experience – not just as ambience. Bill Fontana’s remarkable, ever-changing soundscape has achieved all of that, and more – we have enjoyed a very strong and positive response from audiences. The sound playback system has proved to be ultra-reliable and just what we need for this important exhibit in our fair city.”