Measuring moderator efficiency

[Gragson]

First up I am a bit mutton, self inflicted very loud music in my yooof mostly, so I find it a bit difficult to naturally notice how much moderators reduce sound.
Have a fair selection of moderators and a few strippers now which I can interchange between guns, nerdy thing is I would like to test their relative efficiency to reducing noise.

I used to work on custom race bikes. This no name sound level measure used to give me ball park for MOT and even Santa Pod RWYB drag strip had sound level restrictions.



I can mount the measure device on a tripod, but any tips on where to position or even if this sort of 10 y/o cheapo measuring device would work well for air rifle mods? Cheers Chris

 

[TimD81]

just put it in the same place each time you test different mods so its consistent. be it 4" infront, 10" infront or whatever you choose, but keep it the same each time

 

[xlucine]

As Tim said, consistency is key - the closer the muzzle is to the meter the more signal will arrive at the meter to be measured, but it also makes the measurement more sensitive to slight variation in position. I'd start at 1 ft and see how consistent the results were.

An airgun is also probably fairly directional, and so the meter should be in the same direction relative to the muzzle each time (i.e. just off the path of the pellet, or off to the side, or where your head would be when firing). Think about what direction you care about more - are you more interested in whether it's quieter for whoever's firing, or other shooters on the same range, or not spooking a furry pest that you're shooting at?

For the meter settings I'd aim to get it close enough that you can use the high range, and put it in fast time weighting. A-weighting will probably be fine, and set it to hold the highest level (since the peak will flash by on the screen too fast to read).

 

[Neil54]

Mk1 ear.

 

[RDS1952]

There is another, much longer, recent thread on this