Designed by a workgroup of three Italian acoustic researchers (Mario Di Cola, Davide Doldi and Davide Saronni), the system consists of three-way full-range high directivity line array elements for long-throw applications. Laboratorio Musicale’s Vanis Dondi, explains: "Two direct radiation 18" woofers reproduce the full bandwidth down to 32Hz, virtually eliminating the need for additional sub-woofers in many applications but, if necessary, there are also optional sub-woofers with three long excursion 18" for extra VLF power."
Three Stage Accompany neodymium ribbon compact drivers are the system’s cylindrical HF source for true line source array radiation at HF and Italian 18 Sound cone speakers (used throughout) incorporate features such as Double Demodulating Ring, Double Silicon Spider, Interleaved Sandwich Voice-Coil and custom weather-proof protection. Two horn-loaded 10" mid range speakers ensure improved vertical control in the mid band.
Dondi continues: "Arrays are configured to give required vertical coverage, while horizontal coverage remains the nominal 90 degrees of a single element, resulting in full vertical coverage predictability of the entire cluster, uniform SPL and frequency response over the area covered, minimizing problems associated with traditional arrays, such as comb filtering and lobing. Cylindrical HF radiation, thanks to the ribbon drivers, ensures the system the unique attenuation property typical of this type of sources (3dB each time the distance doubles), giving better fidelity and high intelligibility even in highly reverberant conditions."
The two direct radiating 18"s for the low range (from 32Hz to 140Hz) feature completely water-proof custom fibre reinforced and coated cones, ISV aluminium voice coils that are dual layer coils (internally and externally wound) with twice the cooling capacity and consequently a power compression level of no more than 2.4dB at full power (approximately half that of a conventional transducer). The mid range is handled by two 10" horn-loaded transducers operating from 140Hz to about 1100Hz. The patented Stage Accompany HF ribbon driver is the most natural cylindrical source and is the closest approximation to an isophasic line source; its harmonic and intermodulating distortion is about a tenth that of compression drivers, ensuring natural, high definition HF sound.
Dondi concludes: "Up to 16 LiSA boxes can be hung per array, element-to-element angles possible range from 0 to 10 degrees and flying is precisely addressed using the set-up’s integrated hanging system. LiSA is designed for use with a DSP unit, currently a Crown USM810 digital matrix processor, featuring four SHARC DSPs externally controlled by IQ software. The main system power limiting is via an Avalon VT 747 Stereo Vacuum Tube Comp unit for safe, smooth, inaudible protection when operating at maximum level. Power is courtesy of Crest P8001 amplifiers for the whole system, except the subs which are powered by P9001s. The power ratings per element are 1400W, 600W and 200W (AES) continuous power for low, mid and high frequency respectively."
