The Siren Board

Hello, I would like to build a mini siren. I need help finding out how speed, chopper slots effects the sound.
Thanks

https://airraidsirens.com/forums/viewtopic.php?p=15565

Remember the higher the speed the higher the pitch.

holler wrote:https://airraidsirens.com/forums/viewtopic.php?p=15565

Remember the higher the speed the higher the pitch.

Thank you. Still getting use to Tapatalk(can't search that well)

If a chopper has n ports, it will produce n pulses of air for every revolution. Multiply n by the number of revolutions per second and you have frequency in Hz (pulses, or cycles, per second). Since most motor speeds are given in revolutions per minute (RPM), you must divide motor speed by 60 to get revolutions per second. The whole equation is:

Frequency (Hz) = (RPM / 60) x n

landmobile wrote:If a chopper has n ports, it will produce n pulses of air for every revolution. Multiply n by the number of revolutions per second and you have frequency in Hz (pulses, or cycles, per second). Since most motor speeds are given in revolutions per minute (RPM), you must divide motor speed by 60 to get revolutions per second. The whole equation is:

Frequency (Hz) = (RPM / 60) x n

But bigger the slot the louder??

lilrags16 wrote:

landmobile wrote:If a chopper has n ports, it will produce n pulses of air for every revolution. Multiply n by the number of revolutions per second and you have frequency in Hz (pulses, or cycles, per second). Since most motor speeds are given in revolutions per minute (RPM), you must divide motor speed by 60 to get revolutions per second. The whole equation is:

Frequency (Hz) = (RPM / 60) x n

But bigger the slot the louder??

Larger slots are one of the ways you can increase airflow. Increased airflow will make the siren louder, however larger ports might not always do this as the intake size can limit airflow as well.