Whisper Sound Level Test Comparison

vinceb - 2/12/2008  11:11 AM

it would be interesting to take this a step farther, and mount the barrel in a relatively soundproof barrier and check both sides of it. That way, the relative levels of muzzle and powerplant noise can be compared.

good idea, but very hard to isolate, since sound is actually just vibration. the vibration of the mechanics will still carry through the barrel. you'd have to have the whole mechanism in a sealed/dead chamber, making firing the thing almost impossible.

like I said in my other post, I am going to compare notes with him once I use my dB meter on it, and we can compile both of our findings and hopefully have some objective data. he has a very good comparison range going so far.

I too have a basement studio (I am a drummer) and had to sound-dead the room in order to keep from irritating the fiancee. I had a dB meter from another earlier band when we were trying to construct some cheap sound proofing and needed to measure our results.

it will be interesting to see how much of a threshold shift there is between two of the same models.

when I get home and get the time to set it up properly I will post distances used (X,Y,Z) in relation to each part of the rifle, then he can do the same testing. it should be a fun comparison.

-Mark

[johncedarhill]

The overall sound level of the whisper is not that quiet IMO. The powerplant noise is significant and likely overwhelms the muzzle noise. I would suggest that the the radio shack noise meter is money well spent if you are concerned about noise level. Playing around with the meter can be very enlightening and informative. I was disappointed in the overall noise level of the whisper. To say it is 50 percent quieter (quieter than ??) only requires about a noise reduction of 3 db.

I started to use a dB meter myself as it would have been too easy in comparison to what I ended up doing.  I have a buddy who is a lot brighter than I that I trusted on the matter.  Upon asking to borrow his meter he said, "most meters aren't good at reading instantaneous pops and that's why all the sound level CDs have long tones to test by."  He's the one who suggested I use my recording software but even warned me that the mics may be the limiting factor.  I opted to use my best mic, a Shure SM58.  If you're handed at Excel you'll notice that I hid a number of cells as the info was redendant.  Let me know what you see/hear if you do the testing too.

PM me with your email addy and you can compare the three guns souind for yourself.  Anybody short of a deaf person can plainly hear the difference in the sound levels of the Whisper in comparison to either the RWS or the Big Cat.  It's not so easy to tell the difference between the RWS and the Big Cat.  Yes, as the other user pointed out 3 dB is 2X the sound or half the sound, which ever way you prefer to say it.  But there is closer to 10 dB diff between the quietest and loudest guns in the test.


The Whisper was:
low freq diff - db quieter than the RWS 48  -8.90
high freq diff - db quieter than the RWS 48  -13.40

johncedarhill - 2/12/2008  2:41 PM

The overall sound level of the whisper is not that quiet IMO.  The powerplant noise is significant and likely overwhelms the  muzzle noise.  I would suggest that the the radio shack noise meter is money well spent if you are concerned about noise level. Playing  around with the meter can be very enlightening and informative. I was disappointed in the overall noise level of the whisper.  To say it is 50 percent quieter (quieter than ??) only requires about a noise reduction of 3 db. 

I agree and disagree.  The powerplant does make a lot of noise pollution that the shooter hears.  But if the noise it created was louder than the muzzle noise it would be heard in the recording.  I guess I need to redo the test with the mic next to the butt stock on each rifle and then compare that.  If you didn't look at the results in the Excel file... the Whisper came in closer to 10 dB quieter than the Big Cat and the RWS...."AT THE MUZZLE."

[johncedarhill]

On the TOG there is free downloadable software for a chrony, The patterns can also be graphed to get relative differences in noise level.

[johncedarhill]

Wrong website for the software chrony. The correct one is talonairgun.com.

After consideration I retested the Whisper's sound levels from a user's perspective.  I ran the same type test using a mic and recording software to capture the sound the user would hear.  WHAT A SURPRISE!!!  As another member stated, "The overall sound level of the whisper is not that quiet IMO".  
  It definitely depends on where you stand as to how much you hear.  At the muzzle the gun is much quieter than the other air rifles tested.  However, almost the opposite held true if you measure the sound levels at the trigger.  

The Whisper was much more similar to the RWS at the trigger than I expected.

Low Freq   db louder than the RWS 48  -2.85
High Freq   db quieter than the RWS 48  -1.69

As you can see and hear, the Whisper has a deeper and muffled sounding report than does the RWS.  Albeit actually louder from the user's perspective.  I could defintiely hear the Whisper's deep long report in comparison to the RWS's short higer pitched report.

Since 3dB = 2x the sound level, then on low fequencies the Whisper was nearly twice as loud as the RWS.  But on high frequencies it was almost half as loud as the RWS.  Now for the kicker.  The RWS had a short tight sound that was nearly half as long in duration as the Whisper.  So when firing the RWS the sound was done but the Whisper was only half way finished making racket.  The RWS's sound duration averaged .072 secs and the Whisper averaged .138 seconds.

In conclusion:  If your intentions are to purchase a gun for hunting that will be quiet as to not scare prey so much, the Whisper's report from the muzzle end is ~10X less than that of the RWS 48 or Gamo Big Cat.  But from the perspective of the shooter, the Whisper will sound a bit louder and the duration of the sound coming from the gun will last nearly twice as long as the RWS.

Again, short MP3 sound files available upon request as well as my latest Excel spreadsheet documentation.

IRBent - 2/12/2008  5:52 PM

It definitely depends on where you stand as to how much you hear.  At the muzzle the gun is much quieter than the other air rifles tested.  However, almost the opposite held true if you measure the sound levels at the trigger.  

As you can see and hear, the Whisper has a deeper and muffled sounding report than does the RWS.  Albeit actually louder from the user's perspective.  I could defintiely hear the Whisper's deep long report in comparison to the RWS's short higer pitched report.

Since 3dB = 2x the sound level, then on low fequencies the Whisper was nearly twice as loud as the RWS.  But on high frequencies it was almost half as loud as the RWS.  Now for the kicker.  The RWS had a short tight sound that was nearly half as long in duration as the Whisper.  So when firing the RWS the sound was done but the Whisper was only half way finished making racket.  The RWS's sound duration averaged .072 secs and the Whisper averaged .138 seconds.

this goes back to that vibration thing I was talking about.  

in order to sound proof a room for example, you are not really "stopping" the sound, just converting it to another form, in that case heat energy. (if you go into a studio, there are NO 90 degree angles anywhere on the walls). that is why the size of a room will really matter when doing a test like this, as would any other clutter in the room, like say, a couch or something that will absorb ambiant room noise.

IRbent did a great job of recording and measuring the shift. it is very unlikely I will get the same results, unless I had a similar shaped room. thats why I mentioned I would post my X,Y,Z locations, to make it a little more useable. at this point I am more interested in the actual dB numbers just for that reason.

and just so everyone knows, the meters at radio shack are not that good of a quality, they are more affordable for a reason. Thats why I bought a high piced model ($450), that actually "records" the sound over a given amount of time, then analyzes it, and gives you the peak over duration, and comparative to what you (as a human hearing range) can actually hear.

it is very true that on a regular dB meter the sound would happen way too fast for it to recognize it.

-Mark

I'm pretty sure the dB ranges will vary depending on location of the mic, meter, or ear.  In my mind what matters the most to me is, "will my prey hear my shot and will the sound spook the prey if I miss?"  Having initially tested with this in mind I'll will say the Whisper will effectively help REDUCE the chance of spooking my prey.  I'd love to see your results if/when you get around to testing the gun.

[johncedarhill]

Certainly a big visual difference in the last set of data you posted. There are so many variables when you "test" sound. Straightshooters site has some interesting comparisons on sound levels of various springers. What we want is a James Bond "pfffft," The movies forget about the reality of mechanical sounds of airguns etc.
 

I guess to really seperate out muzzle sound from the spring sound you would have to build a box to hold the rifle with only the muzzle sticking out and place the mic down range.

[SGTMEATSAUCE]

A bit of info to add, I popped my rubber butt plate off and seen how big the hollow stock is. It is cavernous. I could not find any thick foam or propper filler but did find a NERF football that I split in half and stuffed into the stock. I shoe horned it in with a chisel and filled the whole stock to the top, put my butt plate back on and shot it a couple of times. What I did notice was a bit better balence and a large difference in the "shooters" noise level. It took alot of the twang and just left the smack, and a much deeper smack, no more resonance or vibration, probably worth doing again. Just my thoughts.

Sounds like an idea.  Maybe I'll get around to stuffing the butt of the stock and redoing the sound tests at the trigger area.  Bad thing is, I'll have to redo the full test before and after because the mic volume level may not match my initial test.