News:

Enjoy your summer, and stay safe!

Main Menu

Recent posts

#1
Thanks for starting a new thread.  I'd agree that timbre is something that we humans react to.  In the end, with some finite degree of precision, I'd say these effects can be quantifiably characterized.

Let me make a conjecture, what we are somewhat concerned with is reducing the report to the extent it's hearing safe or quieter and making it hard to direction find the location for unassisted humans.  Bonus points will be given for extending this to game.  Further points given for "pleasantness", which is subjective, but undeniably important.  If I've left something out, feel free to add it.  This is meant to be a conversation starter, not a declaration.

So what characteristics of the source make it easier or harder to DF?  What characteristics makes the sound more pleasant?  Perhaps if we can state these we could create goals or targets to achieve?
#2
General Airgun Forum Discussion / Re: Psychoacoustics
Last post by Alan - April 21, 2024, 03:35:32 AM
I take note of the fact, that the author (OldSpook) stated his graphs "...may be off a millisecond or two..." That small variance may not sound (no pun intended) like much, but to our ears and brain it does! In fact, timbre (perceived sounds) is how our brains differentiate subtle differences in voices and music.

Steve you're correct. Hiding behind a faux voile of secrecy is the height of ignorance!
#3
General Airgun Forum Discussion / Re: Psychoacoustics
Last post by steveoh - April 20, 2024, 07:59:03 PM
Interesting work!

I watch a bunch of videos from Ukraine and I'm often amazed at how much audio from weapons gets compressed and made totally unimpressive even though I know the reality is deafening.

But I have to say that someone at the AGN has their panties all bunched up.

#5
General Airgun Forum Discussion / Re: Psychoacoustics
Last post by Alan - April 20, 2024, 01:44:55 PM
I agree, about starting anew.

All of this is not airgun-related directly. However, we experience psychoacoustics in everyday life, and it is important to know how this affects the way we hear all sorts of noise. In order to do that, there are a few things we need to know, whether we understand them or not.

One of these is the perception of changes in frequency, an issue which gets a bit complicated. The main complication (in the context we're talking about...suppressors) is ERB. This stands for Equivalent Rectangular Bandwidth. In simple terms, it is the way we differentiate frequencies across our hearing spectrum (which varies with age). Again, simply put, we can easily differentiate changes in low frequencies (≈20 to ≈200 Hz) as low as a few Hz. As the frequency increases, the change in frequency needs to be greater in order for us to determine a change. At about 20,000 Hz (darn few humans can hear this high), a change of less than a few kilohertz can't be heard.

We need to remember, that suppressors don't change the total energy of the muzzle blast we hear, but rather extend it over both time and frequency. It should be apparent then, that one specific individual will interpret the report of any suppressor differently than another individual might.

In order to level the measurement field, it is important to establish a specific test scenario for any we undertake to measure suppressors. Or speakers! Or microphones! Or traffic noise! In other words, without a specific set of standards to follow, any test we do, is more subjective than objective.
#7
General Airgun Forum Discussion / Psychoacoustics
Last post by olddog - April 20, 2024, 12:07:53 PM
This thread started here:
Origin
Be sure to read the posts there before commenting here.
 ;)
#8
Yes, we've blown this all out of proportions! Sound and air pressure are words used to describe the same function. In this specific case, the frequencies vary from infrasonic to ultrasonic, and are measured by the same microphone. Thus to really tell what's going on, you have to segment (essentially) this spectrum. You also need to consider which part (and pressure) of the spectrum is dangerous to human hearing. It is a very complex issue and one you can qualify and quantify, but you cannot suppress (no pun intended) subjectivity! The correct word for this is, psychoacoustics.
#9
PCP, C02, and Helium Powered Airguns / FX Dynamic Express 500mm .22
Last post by Tinkerer - April 19, 2024, 05:44:42 PM
Yup I went and bought one of these.
  The Dynamic just appealed to me. I did change the carbon bottle to a 480cc 300 bar fill.  I also happened to have a 500mm .22 heavy barrel liner that got installed too.  The stock liner wouldn't shoot light slugs at all.  Even the 17.1 grain NSA.  Pellets were OK.
My initial impressions were the airgun looks much better in hand than in the videos. Handles and shoulders nicely for me being 6'-1". 
  It came with the reg set at 140 bar and I chose to reduce it down some to start shooting and tuning.  Unfortunately it doesn't like lower reg settings due to having the tungsten hammer installed.  The current reg setting is 135 bars shooting 20.2gr NSA slugs at 1017 fps and she is very happy.  The longest distance I can shoot is 50 yards and we normally have KYL targets setup.  This Dynamic has proven to be very accurate to shoot.  My partner doesn't normally shoot the smaller KYL paddles at all. His confidence is sorely lacking, so he doesn't shoot the 1/4" paddle.  With this Dynamic and my prodding he decided to try and he was able to shoot the 1/4" paddle at 50 yards.  He then began to enjoy shooting all the paddles.
  I was very surprised that this 500mm barreled Dynamic is capable of shooting slugs at this level of performance.  I have shot the 24.8gr NSA slugs @ 968 fps by adjusting the Macro and Micro.  I have not tried to see where the fps will max out.  I'm happy where and she shoots.
#10
I don't want to dampen the discussion, but this was just an introduction post.  Can we continue the discussion in a more appropriate section?  Perhaps a more descriptively titled thread?

All good points so far. 

Where's a good section to continue?