The Blue Valley High School is proposing a newly revised Public Address System for the High School Football Stadium. This is NOT the tower previously proposed but a new system entirely.

Public Hearing

What?

Update/Overview of project

Please see the attached letter from an acoustical consultant working for Johnson County to oversee this project. Also please see related article including photos and proposed sound system. This includes an image that superimposes the sound map created by the consultant over a map of surrounding properties--so you can see the decibel reading (a measurement of sound) at your property.

For the last two years representatives of Blue Valley Riding, Sylvan Lakes and Willow Bend, with input from Blue Valley Heights (on Outlook, east of high school) have been working with John Glessner, Design and Construction Manager, Blue Valley School District, the Johnson county planners, and two acoustical consultants, to help review neighborhood concerns about the football PA system. We have all been pleased with the working relationship with the school district and we appreciated all the long hours, the many meetings, and all hard work everyone contributed to these efforts.

Problems arose over two years ago: the PA system had deteriorated and many homes were being bombarded with noise levels well above 67dBA and over 70 dBA (sound measurements). The sound was so bad for many homes that residents left every time a football game was played, others testified that even in a closed house the sound came through loud and clear. Some said that the sound even caused items in the house to vibrate and jump.

The concerns were intensified because so many events were occuring at the stadium. In fact, the new Blue Valley West HIgh School plays all of its games at the BVHS stadium too.

First Proposal Asks For New, High Sound Rules

In late 2000, the high school proposed an expensive 30-foot PA tower with 3 huge loud speakers attached. The school also wanted a new standard of 67dBA outside the school property for the PA system. Residents opposed this new 67 dBA sound limit as both Johnson County and Overland Park noise ordinances and regulations state that noise shall not exceed 60 dBA in residential neighborhoods. Keep in mind--ALL of the other Blue Valley High Schools are bound by the 60 dBA limit.

Residents mounted a protest petition against this new decibel limit--as this could have far-reaching consequences for other development that impacted the neighborhoods.

Revised Proposal Submitted

The school district revised the proposal, scrapped the old system, and redesigned the PA system. Here is the new proposal:

• Construct four, 45-foot tall poles, spaced 50-feet apart and centered behind the larger northwest bleachers with another pair centered behind the southwest bleachers.
• Construct an additional 45-foot pole for the east bleachers.
• Install 8 loud speakers on these poles that can be tilted to provide sound coverage to the stadium.

(Again, please see related article for the actual sound trial of how these will work--also see the maps provided by the school district. Please be patient as some of this downloads a bit slow. The school district and its consultant Acoustical Design Group and George Damon, have a map to show PA design as well.)

Model Simulates Sound In Neighborhood

Bob Coffeen, Acoustical Consultant working for Johnson County, ran a simulation of how these speakers will work. See his letter below and the previously mentioned color map of his results. We are hopeful that this new PA system will provide the high school with the sound it needs while allowing surrounding neighborhoods the protection from the previous harsh sounds of 67 dBA and above.

One home on Outlook at 16001 Outlook would experience 63 dBA according to this simulation. This would only be the case, however, if the levels at the speaker were set to 87 dBA (2 dbA above the last proposal), which emphasizes that how loud the speaker is turned up will make a big difference to the neighborhoods. This is why neighbors do not want to replace the current 60dBA ordinances in Johnson County and Overland Park with a higher dBA level.

Please attend the hearing to voice your concerns or let us know and we can forward your concerns for the hearing.

If there are questions, please let us know.

Shirley and Bob Phillips
Reporting for NeighborhoodNet and members Steering Committee High School PA System

Mr. Coffeen's Letter:

R.C. Coffeen Consultant in Acoustics 9214 Manor Road Leawood, KS 66206

August 5, 2002

Mr. Paul Greeley Department of Planning, Development, and Codes Johnson County, Kansas 111 h Cherry Olathe, KS 66061

Re: Proposed new sound reinforcement system Blue Valley High School Stadium

Dear Paul:

Here is information relating to the estimated sound pressure levels that will be produced in the residential areas surrounding the Blue Valley High School Football/Soccer Stadium as produced by the proposed new sound reinforcement system.

Transmitted with this letter is a sound pressure level map which was used to estimate the sound pressure levels expressed in dBA. The loudspeaker system design on which this map is based is the revised system as described by e-mail message from George Damon of ADG dated May 29, 2002.

The proposed loudspeaker system was set in the acoustical design and analysis program EASE to produce levels of approximately 87 dBA in the Stadium (relatively loud sound). The sound pressure level map reflects loudspeaker system operation at this level. This is 2 dB above the level of 85 previously assumed. I added 2 dB as a "safety factor."

The transmitted map indicates sound pressure levels in the one-third octave band centered at 1,000 Hz. Assuming that the same levels are produced in all of the one-third octave bands from 500 Hz through 3,150 Hz, the resulting A Scale level will be approximately 8 dB above the 1,000 Hz one-third octave band level. This situation is reflected by the table below the map for eight house locations. Note that the estimated A Scale level exceeds 60 dBA for only one house location, the house located on Outlook directly east of the Stadium, and the estimated level at this house is only 63 dBA. Also please note that the map and table indicate levels from the direct sound. No excess attenuation has been considered due to air absorption, absorption of the ground cover, etc. The map also indicates shadow areas due to the Stadium seating stand, the high round immediately east of the Stadium, and the school building. In the shadow areas the sound pressure levels will be somewhat lower than surrounding areas.

It is my opinion that the revised and proposed loudspeaker arrangement will provide acceptable sound levels in the residential areas surrounding the Stadium. And, it is predicted that it will provide lower levels in the surrounding areas when compared with the original central cluster concept.

Please phone or send e-mail if you have any questions or if any additional information is desired at this time.

Very truly yours,

Robert C. Coffeen

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