Bow Noise/Decibel meter

[ThunderXB]

Speaking about bow noise and the new "suppressed" Micro, has any one on hear actually used a decibel meter to measure the sound and differences the "sound suppressing" add on's make?

[Patcon]

You would think Excalibur would have done this during R&D. I would assume they tried a bunch of different techniques for quieting these bows versus loss of speed and then came up with a compromise package. Whether they will release the stats or not is another thing...Gun suppressors always tout their noise suppression as part of the marketing specs.

[galamb]

Gun suppressors always tout their noise suppression as part of the marketing specs.

You are talking about two very different reasons for sound suppression.

With the gun they are marketing a product to save your hearing. There is no illusion that the gun will still be "loud", just quiet enough that with additional hearing protection you won't damage your hearing.

A crossbow is never going to be loud enough to hurt your hearing and you are never going to make it quiet enough so that "game" won't hear it when it's fired. So in the case of "making the crossbow quiet" it's only to make you "feel better".

A deer will bolt sometimes if you do nothing more than brush your sleeve against a tree trunk - so is there really any level of "quiet" that can be installed on a crossbow that would make it "soundless" ????

[nchunterkw]

A guy on another forum has one and tried to make some measurements. Pretty much had no luck discerning any difference in anything.

Here's another thought for you........ever listen to an arrow when it's shot? Put a video camera on top of your target and shoot about 2" under it with different fletchings. The bow certainly isn't the only thing making noise.

Not only will this let you hear differences, the video is a hoot to watch. My wife kept jumpng out of the way every time an arrow came in while we were watching the video in the house.

[Patcon]

My point was suppressor manufacturers provide specs even if they are only 1 or 2 decibels quieter. That is not the difference in whether one can is hearing safe or not. Pretty much every suppressor is hearing safe. It is an attempt to provide information that their can works the best. I would think Excalibur did similar research for the sound suppression they added; unless they added it just to make people feel their bow is quieter.
Also some suppressed firearms are very quiet...if they are shooting subsonic
I also agree the bow is never going to be silent but I like the idea if it being quieter just for me and possibly for the deer that might come by 30 minutes later...

[racking up points]

I like the idea if it being quieter just for me and possibly for the deer that might come by 30 minutes later...

I shoot my bows naked, (the bow I mean...with only the bare minimum in silencing efforts), and I have twice shot and killed deer with my crossbows that were with other deer that didn't spoon after the first shot and allowed a follow up shot on my second kills. The deer aren't all that smart. I wouldn't think a few overpriced hockey pucks stuck to my crossbow would make any difference to a deer that wouldn't be in bow range for another 30 minutes, but that's just me.

[ThunderXB]

Just curious to see if the "sound suppressing" add ons really make much difference and the only real way to know that is a viable means of measurement.

Not trying to make a point one way or the other ., but if I knew there was not much actual noise difference, I'd start taking some stuff off to get back the speed it might be costing me.

If I knew it made a difference, I'd leave it on.

[SEW]

I expect very few have gone to greater lengths than have I to quieten my 380 & 405. Now the 380 & 405 went on a diet. I've left the Air Brakes on the 405 but not the 380 (never on the 400). What's left is: Polystyrene packed stocks, double shrink wrapped arrow hold down spring, TT, DrS limb silencers , bumpers, and stirrup, Flemish string (Vixenmaster)420g arrows. That's it on the 380&400. 405 has the addition of the Air Brakes ( I think they may help prevent limb breakage). I think that it is possible to put string slap rubber strips that will stay. This would help also.



When this was shot with 3" factory fletched slight offset vanes on STs, with a total weight of 486g (FOCs), both the bow and arrow were very quiet. The Boo 175g string with string silencers, which has >1,000 shots, still looks new is a factor in this quietness.

However, the 380 & 400 are essentially clean except for strings, full DrStirrup , packed stocks,TT, double shrink wrapped arrow hold down spring which is bent such that it won't slap the riser after launch, light Flemish strings, 420g arrows. So, they can be quietened w/o loosing much velocity.
I think the BD400 is inherently quieter than the 380 and is 5'/sec faster ( this testing was with the same limbs and string - so, I believe with a 395g arrow, the design of the BD400 is 5'/sec faster). Limbs, strings could make the comparison radically different. This is why I actually used the same limbs and optimum brace height on each.
All this rambling may help somebody.

[ThunderXB]

Ramble on! I enjoy the reading AND the thought process!!

When you pulled the airbrakes off the 380, did you you chrono to see what the speed difference was??

(BTW,How do you like those tactical tapps?? I just talked to Jerry about them the other day (how did you set them up?).)

[SEW]

5-7'/sec. I bought a few dozen of the factory fletched STs. Stripped 3 dozen, spine tested/marked, refletched. So no TTs. Incidentally, spine testing before defletching and then using the stiff side for the cock feather resulted in nearly equal accuracy.

[ThunderXB]

Did you feel that air brakes quieted the bow at ALL? Or just helped with 405 limb issues?

On the STs, so indexing the spine basically had no effect?

Fletched with SK300s & just straight offset?

[Patcon]

SEW
Do you have access to a decibel meter? I have a friend from church that has one but I'm not sure I could borrow it. It would be really interesting to actually measure how much difference your efforts made.
Racking up points
That is interesting you could make a follow up shot without spooking them. Thanks for the info

[Utah Hunter]

You might try one of the free cell phone apps that makes your phone a decibel meter.

[Kegbelly]

I played around with a few iPhone decibel meter apps when I was doing some testing a few years ago. Looking at the averages over many shots I could see a little bit of difference between a 350 grain arrow and 400 gr, and some minor differences between strings, but it was really erratic. I wouldn't consider it an accurate or reliable measure of the sound production. I've done the usual sound deadening mods but that was for my own enjoyment to make my backyard sessions more pleasant. You would really need to set up in an acoustic chamber with some quality equipment to get realistic and accurate data to see how a particular mod affects the sound level.

[onegunguitar]

If you ask me,the noise I notice the most is when the trigger claw lets go of the string. All that poundage letting loose makes more noise than anything,at least that's what my ears tell me