drockw

These wont be accurate enough to conduct an accurate sound test. The problem is, most of the free, or cheaper db testers dont scan enough times per second to read something like a bow. A bows peak noise happens so fast that reading could be very mixed.

Ill try to find another thread where this was done successfully tho using a cheap meter...

drockw

http://www.archerytalk.com/vb/showth...ght=noise+test

After this guys first noise test/comparison, he was persuaded to conduct a more accurate test to determine better results.

bigcountry

Depends on your computers rate. I know for a fact that samples in the microsecond range is 10 times more than adequate for a very very simple bow test. These are the same ones use in our lab to calcuate earthquake tests on optics.

Let me explain how this works. One, its not a db tester. A microphone (or any 8ohm speaker works) is an analog signal. You need a Analog to digital converter to change voltage to digital signal. Even though these are shareware, as long as the computers ossilator is fast enough, it can easily sample high enough. The programs I am referring too just does the analysis. These guys are just using a db scale. Not even in the same ballpark.

bigcountry

I mean know offense here drock, but do you understand what a fourier analysis is?

How many samples/second do you think you need to get accurate frequency content along with p-p analysis?

Since a bow string probably is maximum moving at 400ft/sec, I bet you would gather 90% of the frequency data in sampling 1/400sec.

Using a National instruments DAC card along with some matlab code could easily catch 1billion samples/sec.

drockw

No I do not. An that is, as you said TOTALLY different than what I was thinking, and or referring to. I ASSUMED(we all know what that does) that you were referring to something with much less capability haha.

Sorry about the confusion. Obviously not some 2-300$ db meter capabilities here!

Thanks for the insight BC. What do u do???

GMMAT

I think we put too much emphasis on (worry, needlessly) what the bow sounds like to us......and never think to test the "noise" from the perspective of the deer.

Personal opinion.

bigcountry

Like, I said, I was not trying to be rude. This is just what I kinda do for a living. Your a good guy, so sorry if it came accross bad. I do alot of analog to digital conversions and analysis with light, movement, whatveve. The job can be done for dollars. Just the cost of a microphone. And different microphones will add different noise. It does take however some understanding in engineering. I kinda had an idea about putting together a easy to understand program not geared to graduate engineering students but for this purpose.

Then the problem would be interpreting the results. For instance, if you hit a bass drum hard and created teh same amplitude of sound as say hitting a snare, from the program, you would say they are equal. But to our ears, with archery we would much prefer the bass drum frequency than a ziljan symbol. Also the high frequency could travel further. But then some game animals can perceive lower frequency than we can. Most game animals however have higher spectral range than we do so can hear higher freq. that we can't.

So when these jokers from sims and jax come on with these results, they are not telling 100% of the story. Bottom line is we want a bow that is perceived quiet to a deer/game and ourselves.

There is no perfect tests to compare these too.