Project 213: 'Martin Audio MLA system'

Jason Baird (Martin Audio)
Ambrose Thompson (Martin Audio)

Date meeting:
Thursday May 12, 2011

19:30-20:00 Doors open, coffee
20:00-22:00 Presentations
22:00 Informal ending.

demoroom TM Audio
Krommewetering 131
3543 AN Utrecht

The focus of this lecture is a popular type of line array loudspeaker used for large- and medium-scale sound reinforcement. These systems are required to deliver very high SPL to a large audience area, sometimes as far as 100m from the array, but typically in the 30-70m range. This class of line array is characterised by relatively widely spaced acoustic sources, each with high vertical directionality compared to the more traditional steered column loudspeaker where the acoustic sources are small and tightly spaced. These differences, together with the fact that large audience regions are typically in the near-field, preclude the use of the existing techniques to control linear arrays.

Currently successful methods of control were examined and found to be inadequate for meeting a new more stringent set of user requirements. This lecture describes how users of the modern articulated line array loudspeakers used for high level sound reinforcement can control these systems with more precision, and explains how these requirements can be formed into a mathematical model of the system suitable for numerical optimisation. The primary design variable for optimisation was the complex transfer functions applied to each acoustic source. How the optimised transfer functions were implemented with IIR/FIR filters on typically available hardware is explained, and a comparison made between the predicted and measured output for a large array.

You will find TM Audio on the industrial area 'de Wetering' west of motorway A2 (Amsterdam-Utrecht). Leave at exit 6 (Ring Utrecht-Noord). You enter the area via Nieuwewetering and Proostwetering towards Krommewetering. For the exact position of the locatio please view the map at the bottom of this page.
TM Audio can be reached easily by means of public transport. The local bus 39 provides a half hour service form railway station Utrecht Centraal, busstop Halte Krommewetering Noord. Time of travel about 20 min. The location is at a 15 minutes walking distance from railway station 'Terwijde'. See also:

Ruud Kaltofen (see at the 'bestuur' page)

Please apply by means of the webform.
For members of AES, VPT and VCA participation is free of charge.
Guests entrance fee € 10,- (student guests € 5,-).

(TM Audio: blue pushpin)

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