How loud in decibels is an H motor?

Hello there,

I was wonder how loud an H motor would be in decibels? Any range within 20 decibels is okay.

Thanks,
~Sem

At what distance?

If you are a mile away, it's pretty quite. It you set it off in your ear, it's kinda loud.

for his sake, lets say the Min 100' safe distance.... What motor, IDK , but I'd guess about 60-100 depending on motor.

Also depends on the propellant. (e.g. Sparkies are much louder then say, White Lightning.)


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Likely between 90 and 110 decibels, which is the range or about the same range between a lawn mower and a chain saw.
20 Decibels is a very large range every 10 dB is an order of magnitude increase in power.

You could always just get/borrow a sound meter and measure how loud an H motor is at 100' to get a much more accurate result. If that dosn't work there are cell phone apps that can give you decibel outputs from your microphone. They aren't terribly accurate but its better than "between a lawn mower and a chain saw"

Also frequency, air temperature, humidity, cloud cover, and a whole bunch of other factors will change how loud something is at a distance.

For example, during the Apollo program many tests of the 5 F-1 engines was performed at Marshal. They had performed quite a few tests before with the engines and the sound levels in the nearby towns was at an acceptable level during the tests. However one time it was cloudy outside where it had always been sunny before. The sound from the engines reflected off the clouds and the ground acting like a waveguide to propagate out the sounds much farther than normal. The increased sound levels then blew out many windows in people's houses in the neighboring towns. After this test they made sure they only tested the engines on non cloudy days.

I doubt many people check the sound levels at launches. It does raise some curiosity, and if I can remember, I might run an app on my phone to get some idea for different motors.

Having said that, the apparent volume will very from rocket to rocket. While the initial blast might be similar, slower rockets will sound louder since the distance doesn't increase as rapidly.


Kirk

Thanks for all the answers guys.

If you need quiet, a smokey is hard to beat. A smokey pretty much sounds like a black powder motor. Stay away from skids, they are pretty loud.

You might be able to estimate it
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