Air Gun Home :: View topic

Slavia · Moderator

I got to thinking last night at work - I wonder if there is a way to objectively analyze the results of my modifications?

This wave pattern is from a UMC Pioner 2 (see post under collector guns). I used a cheap microphone held against the compression tube, and recorded with MS Sound Recorder. Saved it as a .wav file, and edited it with the sound analyzer that came with my sound card.

It looks to me like there is a mild pulse when the sear breaks, a stronger one when the spring moves forward, another strong one when the pellet starts moving, followed by decreasing vibrations ("twang"?). The whole event takes about 20 milliseconds.

Right off the bat I can see that I need to turn down the microphone gain so the spikes aren't clipped.

What do you guys think - is this worth refining? What about my technique? My interpretation? How about applications?

Alstone · Moderator & Site Supporter

Hi Slavia
I use a similar system to analyse the sound output of silencers. I have a standard recording made with a manufactures silencer which was done at 10m, and all other recordings are made at this same setting, I can then tell if any of my silencers have been an improvement on the original.

The difficulty I found at first was matching the sound wave to the different noises generated by the gun/silencer, but now I have identified which peaks and troughs match the different parts of the set-up I can tell where I need to adjust thing to reduce the sound.

Some guns especially springers have a background noise that you cannot get rid of, and you can reduce the muzzel noise below this but it only shows on a waveform graph.

So I think your application is a good idea, the problem is interpreting the results.

Have fun.

Al

Slavia · Moderator

You mean I can't just run down to the library and get a copy of "Smith's Standard Reference For Airgun Wavepatterns and Muffin Recipes"?

My first thought was to move away from subjective descriptions like "smoother" and "less twangy." In fact it will probably be those very subjective descriptions that will help interpret the objective squiggly lines.

My minimum expectation is to see the visible result of any modification that I might attempt. Fame, fortune, and the adoration of women might have to wait until later.

billandbeaufort · Senior Member

WOW that is odd! The wave pattern you show there is exactly the same as the first note in "Green Onions" by Booker T & the MGs !!!

Alstone · Moderator & Site Supporter

Slavia · Moderator

You're right! I'll accept Booker T, but the minute one of my springers starts to channel Barry Manilow it's off to the scrap heap.

Alstone · Moderator & Site Supporter

Slavia · Moderator

So here is the Slavia 631. This one has spikes in two distinct areas, and the vibrations taper off differently at the end.

AirGunEric · Site Admin

Slavia · Moderator

You all laugh! You scoff! You ridicule the genius of scientific investigation! Why, as soon as Frau Blucher and I have a stormy night with enough lightning to power our experiment, you'll all see.....