Disappointed in new can

[doubloon]

I tend to believe the muzzle blast instantaneously (< 20ms) increasing the pressure in an entire room would defy the laws of physics unless the room was very small. A jackhammer in a parking lot is quieter to the ear than a jackhammer in a garage even though there is no muzzle blast to fill the room.

But I do agree the shooter experience is louder to the ear in an enclosed space and more harmful than the same exposure out in the open and the "loudness" has a direct relationship to the number of reflective surfaces and their distance from the shooter.

[fishman]

Generally speaking. I'm with doubloon on this one because:



However, right next to a wall or lane divider, using a muzzle brake, the at ear numbers COULD theoretically be higher since the muzzle blast is not the same amplitude in all directions. The pressure wave that bounces off the wall might possibly be higher than the one that travels directly to the ear. Especially is multiple waves are meeting the ear at the same time bounced from different directions.

In the middle of a room, you absolutely wont get higher peak pressure at the ear than you would outside.

Shooting near a big parabolic satelite dish with a focal point at your ear could result in a higher peak pressure. I believe it is the science museum in Chicago that has a parabolic walled room. Two people standing at specific points at opposite ends of a large room can whisper to each other and be heard loud and clear.

Sorry for furthering this thread derail

[SuthDet]

Generally speaking. I'm with doubloon on this one because:



However, right next to a wall or lane divider, using a muzzle brake, the at ear numbers COULD theoretically be higher since the muzzle blast is not the same amplitude in all directions. The pressure wave that bounces off the wall might possibly be higher than the one that travels directly to the ear. Especially is multiple waves are meeting the ear at the same time bounced from different directions.

In the middle of a room, you absolutely wont get higher peak pressure at the ear than you would outside.

Shooting near a big parabolic satelite dish with a focal point at your ear could result in a higher peak pressure. I believe it is the science museum in Chicago that has a parabolic walled room. Two people standing at specific points at opposite ends of a large room can whisper to each other and be heard loud and clear.

Sorry for furthering this thread derail

I'm enjoying the derail.

But again, I'm not saying that they might be louder, or they could be. I'm saying that they have and do meter louder, time and time again.

What I said above is only my theory. I don't have the equipment to measure it, or the education to properly test it. But in a (relatively) small space, gun shots are louder.

The interesting thing is that it isn't consistent. For centerfire rifle, all of the numbers are louder, and the at ear numbers match the muzzle numbers. On 22lr subs, the muzzle numbers are very close to the out side numbers, but the shooters ear numbers are much louder than outside.

By much louder, 6-10db. Again, I can't explain why or how, but it does happen. This is with the muzzle 1 foot inside an open window, roughly 1 foot past the end of the table, and 3 microphones, 1m left and right, and 1 next to the shooter's ear.

[cdhknives]

IMO (I've had fluid dynamics too) some discussions get way too hung up on peaks and neglect the time duration aspects. Hearing damage is both peak and duration. The echo from an overhead roof, walls, etc. may not register as high on a meter but it dang sure is high enough to be considered in the overall 'is this quieter' question...and it isn't only about perception. 130 dB for a single suppressed gunshot pulse may not be damaging but repeated pulses of 130 and then 100+ might. Dunno that I have ever seen authoritative studies on it but I know I still wear my hearing protection when shooting otherwise 'hearing safe' suppressed rifles under a roof.

Also, having a second peak in an enclosed room higher than the initial peak out in the open does not defy physics in the slightest. Waves of most types, sound, water, electric, etc, overlapping will reinforce, and hitting harmonic frequencies can make the amplification increase much more than expected. Acoustics can be very complex and interacting acoustic waves can do funny things.

Bottom line form an old controls engineer: Use dB meter readings with care and don't read too much into them...fun to talk about but only one part of a complex subject!

[doubloon]

Generally speaking. ...
However, right next to a wall or lane divider, using a muzzle brake, the at ear numbers COULD theoretically be higher ...

Agreed as previously stated if the room were small enough or a barrier was close enough.

But even then it might not be every time, it all depends on how fast the mic is and where in the cycle the reverberation hits it.

[doubloon]

IMO (I've had fluid dynamics too) some discussions get way too hung up on peaks and neglect the time duration aspects. Hearing damage is both peak and duration. ...

Agreed as previously stated, everything is louder to your ear in an enclosed space or next to a reflective barrier and therefore worse on your hearing.

Fast mic's are good for capturing the absolute peak sound from gunshot suppressed or not but it doesn't paint a true picture of how it sounds to your ear.

I sometimes slow mic's aren't better for measuring what's really hearing safe and what's not.

[gsyoung54]

I tend to believe the muzzle blast instantaneously (< 20ms) increasing the pressure in an entire room would defy the laws of physics unless the room was very small. A jackhammer in a parking lot is quieter to the ear than a jackhammer in a garage even though there is no muzzle blast to fill the room.

But I do agree the shooter experience is louder to the ear in an enclosed space and more harmful than the same exposure out in the open and the "loudness" has a direct relationship to the number of reflective surfaces and their distance from the shooter.

Can you put the woman riding the horsey back up as your avatar?

[doubloon]

Ha! I'll have to see if I still have it.

[#40Fan]

At the least, use one that doesn't have a google watermark.