I made a signal device today

[rsilvers]

Ha. No, it is safe - but I don't like the moisture in the bread. I think the powder will absorb it.


I am working to do what no one has seemed to have ever done - sound meter various ways to load it - and know for sure what is best - Fg, FFg, FFFg, various charge weights, various wads, Cremora(R), Duct Tape, and two different bore sizes. See if it is true that Pyrodex really does not work as well, etc.


It is kinda malpractice that the dealers of these devices have not already done this.

[Cat Whisperer]

I've oft threatened to take a dB meter from work and make a few measurements.
If you do it, measure the distance from the cannon to the mike and note the orientation and scales you set.

[rsilvers]

1474-D Mil Spec.

1 meter always.

A weighted always.

System response time 20 microseconds or less.

Almost no sound meters can do this.

[carmy53]

I am working to do what no one has seemed to have ever done - sound meter various ways to load it - and know for sure what is best - Fg, FFg, FFFg, various charge weights, various wads, Cremora(R), Duct Tape, and two different bore sizes. See if it is true that Pyrodex really does not work as well, etc.

I'm really looking forward to the results of all this testing. I hope videos of all this will be forthcoming.

[Cannon Cocker]

If you do it, measure the distance from the cannon to the mike and note the orientation and scales you set.

The slightest change in the angle of the thunder mug etc. can change the values a lot.  I would set it on a heavy board so that the ground irregularities will not change the angle that it is directed with repeated shots.  You may even want to have the vent facing the same direction also, as there is some sound coming out of there too.  Just a few ideas.

[rsilvers]

A 50 BMG rifle is about 172 dB. Really, if a 1 inch Thundermug is only as loud as that, then to me it is un-interesting - as it just sounds like a big small arms rifle.


I want 180dB. If this can do it, great. if not, then 1 inch is too small a bore for me.


People have said that a 2 inch bore is a waste of powder. Well, that is not a fact yet in evidence. If a 1 inch can not do more than 170 dB, and a 2 inch can do 180 dB - then I would want a 2 inch.


Whatever it takes. I don't care if it uses $5 of powder per shot. This is not something I can fire often.

[Rayfan87]

55gr in my 56 Cal cannon sounds about like a shotgun going off and echos through a valley very well.

[Artilleryman]

I wonder how loud (db) full scale field pieces firing service loads are?  I never thought about measuring sound levels.  If I can find a meter I could check various guns at Grayling this coming July.  Sound from various guns have different qualities.  The small bore, short barreled guns have a more piercing sound than the large bore guns which have a lower pitch boom to them.

[Cannon Cocker]

A 50 BMG rifle is about 172 dB. Really, if a 1 inch Thundermug is only as loud as that, then to me it is un-interesting - as it just sounds like a big small arms rifle.

I think you may find it interesting even if the decibels aren't equal.  Having heard many different kinds of explosions (full scale service loads in cannon, air burst salutes, different types of high explosives) they all have a different quality (other than just volume) and I like them all.  If it were just about volume I'd be happy popping a packing bubbles close to my ear. 

[rsilvers]

True. I want a deep sound that no one would think was a gunshot.

[Artilleryman]

I don't think you are going to get a deep sound unless you have a full scale gun such as a Napoleon.

[Cat Whisperer]

1474-D Mil Spec.

1 meter always.

A weighted always.

System response time 20 microseconds or less.

Almost no sound meters can do this.

With some you might find the mike blown out if you use 1 meter.
Since the sound diminishes with the square of the distance, if you know the distance (further) you can calculate back to the standard.

dBA makes sense, as that is the weighting of the human ear.

We use the SPER meters, I'll have to look to see if the FAST setting meets the 20uS.

[Cat Whisperer]

If you do it, measure the distance from the cannon to the mike and note the orientation and scales you set.

The slightest change in the angle of the thunder mug etc. can change the values a lot.  I would set it on a heavy board so that the ground irregularities will not change the angle that it is directed with repeated shots.  You may even want to have the vent facing the same direction also, as there is some sound coming out of there too.  Just a few ideas.

An illustration or jpg of the setup might prove useful.

[rsilvers]

With some you might find the mike blown out if you use 1 meter.
Since the sound diminishes with the square of the distance, if you know the distance (further) you can calculate back to the standard.

dBA makes sense, as that is the weighting of the human ear.

We use the SPER meters, I'll have to look to see if the FAST setting meets the 20uS.

My meter only goes up to 170 dB, so I put it at 2 meters. It indicated 164 dB. I then added 6dB to show what it would have been at 1 meter.


For a mic, you need a 1/4 inch


I don't see the SPER meter as 20 microseconds. I am not aware of any new meter under $12,000 which meet that spec. I ended up buying a very old reconditioned meter in order to do it. The mic alone was $800, and that was getting the off brand.


http://www.silencertalk.com/2209-method.htm

[ironball]

The level of volume isn't as important as the frequency of the sound waves. In this case, a lower frequency boom is going to be much more satisfying than a louder, sharper bang. Like at a really loud concert, the drumming and the bass notes are the ones you feel hitting you in the chest. The shrill treble notes can be just plain annoying.

[rsilvers]

Yeah. It would be great to hear all of the different configurations and then see which one seemed impressive to me.