Meyer Sound Labs
M3D Line Array Speaker System
Presented by
John Monitto
Meyer Sound Labs

meeting pictures 

Meeting held May 19, 2001
 

The PNW Section took advantage of a bid proposal sound system installation in Seattle's Benaroya Hall to examine concert line array speakers. Benaroya Hall is a Cyril Harris acoustic design that is the home of the Seattle Symphony. Amplified shows are being added, and concert sound systems being proposed. The meeting was opened by PNW committeeman Rick Chinn. The 33 or so attendees passed the mic and introduced themselves. Then a door prize drawing for a slew of Meyer T-shirts and a Meyer tour jacket was held.

Rick displayed an Atlas sound column circa 1962 as an example of an older line array. Then John Monitto of Meyer Sound Labs (MSL) presented PowerPoint slides comparing old line array technology versus new.

He showed plots of a line array of omni sources. Nulls appear in the vocal range, which move depending upon the source spacing. He showed patent drawings of designs using horns to try to get a ribbon source effect. Similar problems remained.

MSL felt they had to produce a line array for the market. John Meyer wanted to try a ribbon driver. He built one, with very large magnets. It sucked power, saturated quickly and needed a lot of cooling - not practical. He tried emulating a ribbon using compression drivers in a special manifold, which is what they ended up with. They did research and tested it in their anechoic chamber, tweaking empirically. The resulting MSL M3D system is what was being demonstrated at Benaroya Hall.

The low frequency drivers use some of their MSL X-10 woofer technology, although without the X-10 pressure sensor system. The backside of line arrays typically give a lot of low energy out the back. MSL used their "cardioid woofer" technique, using phased and delayed LF drivers to keep the LF energy forward.

The system is self powered, with 4 channels x1280 watts in each box - all analog. "Intelligent" AC figures out the mains voltage. There is a Meyer data monitoring system for remote sensing of performance parameters. The system is designed to integrate well with other MSL products in terms of polar patterns and phase responses. This system goes down to 40 Hz, with an optional sub to go down further. The rigging was carefully designed with modular, adjustable, easy to replace frames. Cabinets retain splay angles when hung and tilted. The design safety margin was 7 to 1 (a European requirement). The design is weather protected.

MSL previously did impulse response studies in Benaroya Hall to design a center cluster. They used this data to design this line array proposal, which was used for a concert the night before.

Extensive material was played through the system - music, tones, noise. Attendees took the opportunity to roam the hall and hear the results.

Special thanks is extended to Benaroya Hall for giving us access to this event.
 

report by Gary Louie, PNW Secretary

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Last modified 11/4/2001.