Paintball

[flightline]

Hey All,

I've been working on my bachelor's degree for the last 2 years, and have finally gotten to my last class. I am going for an Electronics Engineering Technology degree, so the last class is a Capstone Project in which we come up with a project, then design and build it.

Just like you, I am a paintball nut. Why not do something with paintball? I decided that I wanted to test the decibel level (loudness) of my Ego 10 and do some tests with some various bolts to see if there is any real sound level difference. Not only did this sound like a lot of fun to me, it gave me a reason to go out and buy a bunch of stuff like the bolts and a chrono. Hey, the wife couldn't argue with me too much as the purchases were for school!

So, I got all of the parts and came up with a testing platform. I am in the process of building my own decibel meter, but it's not exactly going too great. I had bought 2 commercial units to help calibrate my design, and they are what I used for the test.

Here is my list of testing materials:
Ego 10 w/ stock 14" .693 bore SHAFT barrel
45/4500 Crossfire Tank
RPS Premium Paint, sized at .684
Radarchron Chronograph
2 Decibel Meters
Stock Planet Eclipse Cure 3, Cure 4 bolts, and TechT Hush, and Kush Bolts.
Pooty-modded Cure 3, Cure 4, and Hush Bolts.

Some Pics:











As you can see, I placed one of the DB meters by the bolt, and one off to the side of the barrel to test the sound both at the operator, and just slightly down range.

For the test, I chronoed the marker to my local field limit of 285 (averaged across 3 shots). I did a 10-shot test per bolt to get a range of readings, then averaged that data across those 10 shots.

I tracked the FPS, DB1 (DB meter by operator), and DB2 (DB meter slightly down ranged) for my data. Here is what I measured in a nutshell.

Cure 3:
FPS: 277.5
DB1: 65.29 DB
DB2: 65.31 DB

Pooty Cure 3:
FPS: 279.4
DB1: 63.58 DB
DB2: 65.92 DB

Cure 4:
FPS: 280.8
DB1: 65.72 DB
DB2: 65.77 DB

Pooty Cure 4:
FPS: 275.7
DB1: 66.93 DB
DB2: 65.35 DB

Hush:
FPS: 278.5
DB1: 61.69 DB
DB2: 65.71 DB

Pooty Hush:
FPS: 275.9
DB1: 62.37 DB
DB2: 63.89 DB

Kush:
FPS: 273.4
DB1: 62.46 DB
DB2: 66.24 DB

For a point of reference, here are some DB levels that you would experience on a daily basis:

Whisper Quiet Library 30dB
Normal conversation (3-5')60-70dB
Telephone dial tone80dB
City Traffic (inside car)85dB

For a final Bolt Test, I measured the FPS jump from the stock Cure 3 chronoed to 285, and compared it to the first 2 shots that I got from each of the other bolts:

Bolt Shot 1/ Shot 2
Pooty Cure3282/290
Cure4289/301
Pooty Cure4293/303
Hush276/295
Pooty Hush303/305
Kush291/318

It would appear that the Pooty Hush overs an overall performance increase over any of the other bolts, albeit very slight. It is just a little more quiet overall, and offers a better increase in efficiency.

So, after I tested all of the bolts, I was curious about barrels and bore sizes. After all, we all swear that a carbon fiber barrel is more quiet. But is it?

I tested 3 barrels and bore sizes. I only did a 5-shot test for the barrels as I was running out of paint and daylight. I also ran this test with a stock Cure 3 bolt.

Planet Eclipse stock 14" SHAFT (Aluminum), .693"
FPS: 281.2
DB1: 63.66 DB
DB2: 65.76 DB

Deadlywind 12" (Carbon Fiber), .693"
FPS: 278.8
DB1: 65.18 DB
DB2: 62.82 DB

Deadlywind 12" (Carbon Fiber), .684" (what I sized the paint to be)
FPS:270.4
DB2: 56.34

All-American Freak 12" (Aluminum), .684"
FPS: 272.8
DB2: 59.76

I wanted to test with an underbore, so I used my smallest Freak insert on the DW only

Deadlywind 12" (Carbon Fiber), .679"
FPS: 279.6
DB2: 55.94 DB

SO, you're wondering what happened to DB1 data? Well, I kinda shot my original DB2 meter after changing the barrel out. I didn't pay close enough attention to where the barrel was pointing. DB meters DO NOT like to be shot with a paintball. In case you were wondering!

Finally, I wanted to test the best combination of Bolt/Barrel to see what I would get. I just eyeballed the data from the Bolt Test, and decided to use the Hush.

Hush Bolt with Deadlywind 12" (Carbon Fiber), .684"
FPS: 281.6
DB2: 61.92 DB

Here is an Excel spreadsheet that I will put together with the complete test data.

Ego 10 Bolt and Barrel DB Testing.xlsx

- flightline

[MaD]

I thought there would be more difference in the bolts. Looks like the biggest difference would be underboring.

[flightline]

Yea, that's what I was thinking. I think that the underbore prevent the air from escaping more freely around the paintball, and kinda keeps the sound behind the ball. If that makes any sense.

I was quite surprised that all of the bolts basically tested the same as far as the sound level was concerned. There is no doubt that the modded bolts are much more efficient. I just figured sound-wise they would be different too.

[russc]

I wonder if dB meters make a distinction between high and low frequencies, because generally speaking when we use rain covers and venturi bolts, it doesn't so much "silence" the guns, as it changes the pitch. A crack becomes a whoomph, which is a bit harder to pick up on the field.

[flightline]

I think that the meters are just looking for the intensity of the sound. High and low freqs will travel differently, thus making them sound different at the distant end.

[PistolRogue]

I think it would be more interesting to place a meter at "engagement"-type ranges, say 50 feet plus. That may show more of a difference since high and low frequencies travel at different rates as Russc mentioned.

[baader]

I draw the same conclusion as I have thought before, different bolts on poppet guns are just vaporware. Few db change does not justify buying a new bolt IMO.

I would have thought there be more change between meter1 and 2, cause it always seems that guns are louder in the shooting direction.

[-=ArchAngel=-]

Originally Posted by baader

I draw the same conclusion as I have thought before, different bolts on poppet guns are just vaporware. Few db change does not justify buying a new bolt IMO.

I would have thought there be more change between meter1 and 2, cause it always seems that guns are louder in the shooting direction.

they do however considerably change the pitch/tone/freq of the marker.

[flightline]

@ Pistol: I totally agree with you. I would love to do this some time. It was just me doing the testing, and it would have taken for freaking ever to walk so much between shots. Plus, it was rather breezy when I did the tests. My ambient DB level was in the 40s most of the time. Would have to wait for a calm day, and get my buddy to come help me out.

@baader: Yea, I agree too. There is really no difference as far as the DB level of the bolts are concerned. I got a much better drop in DB with the barrels.

@ ArchAngel: I think that this is the reason that the DB level seemed to go down when the FPS readings were on the higher side. I think that the higher speed of fire is associated with a higher frequency sound coming from the marker. Thus causing a lower sound "loudness".

[Studwiser]

This is very interesting to say the least, if you do the engagement ranges in testing i will be looking forward to hearing about it. Also when your done with this project and if you want to unload some bolts, "dibs" lol.