Clarification of Dry Fire #'s

[Ucsdryder]

I'm just trying to get an understanding of wtf is happening, because it seems 120 would be way off.


I can put the incorrect inputs into a dyno, and get the wrong hp. I can setup my optical chrono wrong and get the wrong fps. Usually, I like to think I know enough to catch a mistake that makes something wildly off, and I wouldn't use that data.

120db on a dry fire seemed wildly off to me. I was asked if I was trolling for asking if that was incorrect? Or for an explanation of it I guess.

At this point I'm just going to conclude that I have figured this out for myself now.

Everyone with half a brain knows it’s wrong. You’d have to be pretty obtuse to believe it.

 

[BasicUtahrd95]

The question isn't really about comparing a can to a can. I can see some value in saying this can meters this, and this can meters this in these conditions. You aren't saying those numbers are actually accurate, its just under these conditions, this is what the difference of these two are.


But if the number on the on the meter is capturing something that is twice as close as what the meter is designed to be testing at, its gonna skew that in relation to what its measuring at the actual distance its supposed to measure.

I think most are intended to read at a M. So what, 39 1/3 inch? 40 inches makes that number easy to play with. Something that is 20" away for comparison will read 6db higher than what it should, 10" away is going to be 12db greater. So *if a firing pin is 15" away, it might be reading 9 db off. 5" would make it 18db louder.


This isn't making the readings correct. This is just comparison of readings taken at the same time.

Maybe this is for another thread, but what I am curious about, is if the variables in meter setup (location, orientation, environment, etc.) can cause invalid readings (i.e. a poor performing can metering lower than a high performing can). If not, do these same variables allow the meter to be sensitive enough to reliably pick up any differences between cans?

 

[BasicUtahrd95]

In my opinion, no. Certainly not by metering. Simply hearing them side by side has more value than a number on an instrument being used incorrectly and inconsistently in the wrong environment for an application that was never intended by someone who doesn't know how to use it in the first place.

They're all too loud to shoot safely without plugs/muffs.

They're all quiet enough to shoot safely with plugs/muffs.

The numbers are purely for marketing. They mean nothing. There's no standard, no accountability, no functional difference in actual sound suppression between the quality manufacturers.

This makes a ton of sense. Thanks!

 

[alexnelon]

Maybe this is for another thread, but what I am curious about, is if the variables in meter setup (location, orientation, environment, etc.) can cause invalid readings

Yes 1000%

I can influence the readings on a meter by 15+ db simply from where I put it and what I put around it, and 40+ db by changing settings in the meter itself.

 

[Huntnpack 2]

In my opinion, no. Certainly not by metering. Simply hearing them side by side has more value than a number on an instrument being used incorrectly and inconsistently in the wrong environment for an application that was never intended by someone who doesn't know how to use it in the first place.

They're all too loud to shoot safely without plugs/muffs.

They're all quiet enough to shoot safely with plugs/muffs.

The numbers are purely for marketing. They mean nothing. There's no standard, no accountability, no functional difference in actual sound suppression between the quality manufacturers.

Exactly!!

Tone Matters.

 

[alexnelon]

Exactly!!

Tone Matters.

Packaging matters more than dB numbers.

 

[pods8 (Rugged Stitching)]

120db on a dry fire seemed wildly off to me. I was asked if I was trolling for asking if that was incorrect? Or for an explanation of it I guess.

I saw 2 things noted:

-The placement of a meter shows the firing pin reading low 120s when that same meter in that same placement shows a can reading low 120s. Its an observation that raises the question how good any of this data is and/or below a certain threshold.

-Firing pin can be heard over some suppressed shots, there was no statement of WHY just a statement of observation. WHY? I honestly don't know, is it the fact its fractions of a second sooner so it can be heard? Is it a different frequency or such that carries through more?

There was no statement that a firing pin truly IS 120db, just the observations to be sorted out.

 

[Billy Goat]

There was no statement that a firing pin truly IS 120db, just the observations to be sorted out.

There have been statements outside of this thread saying the dry fire is.

Thats why I was asking the question.

Or to the casual reader, those statements are made, I guess without context, and it makes you go wtf.


It seems to me like a meter that is placed in the correct position from one item to measure, then using that same setup to measure something that is closer to it is kinda dumb.

Can say we can't accurately measure below this threshold, because we know this is part of the equation and with the "standard" placement of the pickup for a "shooter's ear" this creates a false reading that makes it difficult to get an accurate reading.

But that hasn't been said that I have seen. And would have been an easy explanation to the question I posed.

 

[Q_Sertorius]

There have been statements outside of this thread saying the dry fire is [120 decibels].

I think those statements “outside this thread” come from people who don’t understand the context for the original statement mindlessly repeating something like it’s gospel. Never seen that before on the Internet.