MEMO. Authorization to Purchase Acoustic Panel Material Operations Building

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1 MEMO TO: From: Board of Directors Acting District Manager Date: September 24, 2014 Subject: Authorization to Purchase Acoustic Panel Material Operations Building Recommendation It is recommended that the Board of Directors review this memo and approve by motion of the Board, the purchase of acoustic panel material for improvements in the acoustics of the existing Operations Building meeting room, not to exceed $2, Background The San Lorenzo Valley Water District conducts the majority of the Board of Directors and Committee meetings in the general meeting room in the Operations Building. The meeting room background noises are elevated causing difficulty in hearing speech during meetings. Recently the District procured the services of Magic Sound to perform an acoustic study for improving the acoustics in the meeting room. Their findings are as follows: The room is 25 by 17 feet with a 10 foot wall high and flat ceiling. Finish details include standard gypsum board wall and ceiling, with linoleum flooring on a concrete slab. Simple furnishings include several folding tables and folding chairs for about 20 people, and small cabinets. The room is uses a conference room, including public and private meetings of the Water District and as a break room for the field employees. The room has two full-height corridor openings and the effect of these on the room acoustics is difficult to model. Therefore, analysis started with an onsite measurement of reverberation time (RT60). This is the main characteristic used in determining the acoustic quality of a room. The measurement shows and RT60 of 1.3 seconds. Using the known dimensions and surface material of the room, a mathematical model was then used to determine the effect of the corridors on the RT60. With this correction factor determined, the model matched the measured value, and it can therefore be used to accurately determine room treatment. 1

2 The calculated and measured RT60 of the untreated conference room is 1.3 seconds, longer than the recommended 0.65 seconds maximum reverberation for a meeting room of this size. Excess reverberation has a negative impact on all activities in the room. It elevates the perceived background noise level and causes difficulty in hearing speech between attendees, resulting in raised voices and loud gavels. The reverberation time of the room should be reduced to 0.65 second or less. The room acoustics calculator described above is easily modified to determine the amount of acoustic material needed to achieve the desired improvement (see attachment). Using the available wall space, a total of 175 square feet of acoustic panel can be installed, reducing the RT60 of the room to 0.67 seconds for approximately $1, At the September 4, 2014 Board meeting your Board approved having the District s Board meetings recorded by Community TV and broadcast on local Television. The installation of acoustic panels will greatly increase the acoustical quality of these recordings and Board meeting. Summary It is recommend that the Board of Directors review this memo and approved by motion of the Board, the purchase of acoustic panel material for improvements in the acoustics of the existing Operations Building meeting room, not to exceed $2, Rick Rogers Acting District Manager 2

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