D48 sounds

[splitbeing]

I love shooting my stock D48. It has a sound that could be more pleasant. I've read GTA members describe the sound as a bwap or a thwap. What sound does your D48 make and what mods (if any) influence that sound production?

[Roadworthy]

Generally spring piston airguns are described as having two common sounds.  One is a twang the spring makes after the gun is fired.  This may be cured by a properly fitted spring.  The other is your thunk.  I believe that is the sound of the piston hitting the end of the compression tube.  It is not generally considered objectionable.  A heavier pellet would likely reduce it aa bit.  An LDC or moderator might help a bit.  A lighter spring would reduce the power and the speed at which the piston travels.  I suspect the  only way to eliminate the sound completely is probably to leave the gun in the safe.

[Toxylon]

My D48 .22 cal is really loud. The extra metal-on-metal contact of the sidelever / moving chamber construction (as opposed to a breakbarrel) adds an extra layer of noise into the equation. Sometimes my ear almost hurts from the shots, as the metallic blast comes from close to the ear. Even my H135 puts most of the ample noise downrange, where it does no harm.

I'm considering getting an OEM moderator for the gun, but know full well it doesn't do anything for the mechanical noise. Overall quieter would still be a boon with the D48.

[dmflyer]

I use my electric earmuffs to isolate the sounds of a spring rifle and see what can be done for noise. You can button compression tubes and pistons as well a tune kit or just tighter spring guides. I just shot mine (22 cal M48) over my uncalibrated db meter and it is 8db louder than my HW30 or about as loud as a pumped up Sheridan. I can't hear the cocking arm rattle at all and it shoots very hard-750 with a 14.3 at 4100 ft. elevation. Gosh I guess I'm a little long- winded tonight, sorry Richard

[splitbeing]

Thanks all. Db aside, I notice the internals make a noise more thwappy than my other spring guns. The Meisterschutze (D34) and K98 (D460) internals don't produce the same noise from the spring and piston seal as the D48.

I love the sound of the cocking of the D48 as well as shooting it. It's my go to gun.

I've read some GTA members replacing the spring and piston seal to produce lower power and change the sound, which partially inspire the original post. But what does it sound like with different springs and seals? Or possible different lubes?

I guess I'm shooting so much that the guns I've settled into after a few years of buying this and that has lead to new obsessions like the sound of operation.

The db is fine for my purposes.

[dmflyer]

My 48 is about 30 years old and has long been tuned up and I can't hear any vibrating sounds-it just goes "bang". I think that is how loud it is without a LDC. It is easy to shoot and the sound is not unpleasant, kind of super staple gunish with a pow

[dmflyer]

I looked at my notes and it has a ARH kit and seal with Krytox 205 so I guess it doesn't diesel. I buttoned the tube to the receiver and the piston with teflon buttons but I didn't do anything to the cocking lever. It has had other set-ups but as long as the seals are good it hasn't really been too different even with a lower power kit, Richard

[DanD]

I used to have a .177 48 a lonnnng time ago. I remember the thing was skull-rattling harsh, loud, and generally unpleasant to shoot. I sold it to a firearms guy that was into that sort of thing.

[splitbeing]

Richard, Could you say more about buttoning the D48? I am not following but am interested in doing so.

[Bad News Beeman]

My .22 48/52 is also just on the verge off being uncomfortably loud. Its got twang, but the piston slamming the compression tube is by far the loudest component. Louder even than my .177 350.

[dmflyer]

I used a carbide end mill to cut a shallow 1/4 hole in a few places around the part I am doing and then sand to fit. ARH glue on buttons work if you use the right glue. If your gun is real loud I would try replacing the breech seal first and then the piston seal, mine was never real loud. I will run a few more guns over the db meter and see how they compare. I have a HW57 under lever gun I think is a little loud in the way we are talking about. There is a lot of extra parts to seal and rattle on a side or underlever rifle compared to a break barrel.

[dmflyer]

I shot a few over the meter, it is hard to measure sound and my meter isn't calibrated so I will compare to the HW30 but the readings were from 65.5 to 75 db.
Old HW50 .177 one db less than the HW30
daisy bb gun the same
new style HW50 11.5 ft. lb. 20 cal +1db gun tuned
HW57 22 13 ft lb +1.2db
HW95 .177, HW35, HW95 20 cal all +1.2 db
R1 22 cal 20+ ft. lb. +7.8 db
Benjamin pump 8 pumps +8db

[splitbeing]

I shot a few over the meter, it is hard to measure sound and my meter isn't calibrated so I will compare to the HW30 but the readings were from 65.5 to 75 db.
Old HW50 .177 one db less than the HW30
daisy bb gun the same
new style HW50 11.5 ft. lb. 20 cal +1db gun tuned
HW57 22 13 ft lb +1.2db
HW95 .177, HW35, HW95 20 cal all +1.2 db
R1 22 cal 20+ ft. lb. +7.8 db
Benjamin pump 8 pumps +8db

Thanks, Richard. Where was the meter relative to the guns when measuring Db?

[dmflyer]

It was only a foot or so from the muzzle of the gun. I have done this before and the numbers were similar but they won't translate to another meters readings so I used the HW30 for comparison. The numbers can be the same for 2 guns yet they might sound completely different to your ear. I shot these from the hip into a bucket of rags, the meter was on my bedroom work bench . They all sound pretty quiet to me.
.

[splitbeing]

It was only a foot or so from the muzzle of the gun. I have done this before and the numbers were similar but they won't translate to another meters readings so I used the HW30 for comparison. The numbers can be the same for 2 guns yet they might sound completely different to your ear. I shot these from the hip into a bucket of rags, the meter was on my bedroom work bench . They all sound pretty quiet to me.
.

Thanks!

I also find the 48 quiet enough. The quality of sound from my R7 when I had one blew the quality of the sound of the 48 out of the water.

[HectorMedina]

It was only a foot or so from the muzzle of the gun. I have done this before and the numbers were similar but they won't translate to another meters readings so I used the HW30 for comparison. The numbers can be the same for 2 guns yet they might sound completely different to your ear. I shot these from the hip into a bucket of rags, the meter was on my bedroom work bench . They all sound pretty quiet to me.
.

Just as a note, FWIW:

Industry standard is to place the dB meter at 1 meter, in a perpendicular direction to the barrel, from the muzzle.
Tests must be conducted in an open space and the target needs to be far enough to not register within the "hold" function time of the meter, or be "dead quiet".
Meters are used in the "B" scale.

Keep well and shoot straight!






HM

[dmflyer]

I bought the meter for testing my off-road motorcycles where quiet is also good. Using it and electric muffs to tune spring guns is fun and works pretty well- a 2db improvement on the same gun is huge.

[HectorMedina]

I bought the meter for testing my off-road motorcycles where quiet is also good. Using it and electric muffs to tune spring guns is fun and works pretty well- a 2db improvement on the same gun is huge.

You are right. Energy wise:

-3 dB is cutting the sound in half
-6 dB is cutting it to a quarter
-9 dB is cutting it to an eighth.

And the reverse scale is also true.

Though the way human ear works, it takes almost 10 dB's increase to make us FEEL that the sound is twice as loud. That is the "problem" with human perception, it is wonderfully adaptive and relying on our senses sometimes leads us to conclusions that are not quite so accurate.

In GENERAL, I do not find the sound of springers excessive, for my hunters I usually add a device, though IMHE, I think the device is more effective in the hunter's perceptions than in the game's ;-)

Anyway, I just thought I would let you know the industry standard because if you want to have comparable measurements (even if the sound meter is not calibrated), you now have the information to do so.

Keep up the good work!







HM

[dmflyer]

I bought the meter for testing my off-road motorcycles where quiet is also good. Using it and electric muffs to tune spring guns is fun and works pretty well- a 2db improvement on the same gun is huge.

You are right. Energy wise:

-3 dB is cutting the sound in half
-6 dB is cutting it to a quarter
-9 dB is cutting it to an eighth.

And the reverse scale is also true.

Though the way human ear works, it takes almost 10 dB's increase to make us FEEL that the sound is twice as loud. That is the "problem" with human perception, it is wonderfully adaptive and relying on our senses sometimes leads us to conclusions that are not quite so accurate.

In GENERAL, I do not find the sound of springers excessive, for my hunters I usually add a device, though IMHE, I think the device is more effective in the hunter's perceptions than in the game's ;-)

Anyway, I just thought I would let you know the industry standard because if you want to have comparable measurements (even if the sound meter is not calibrated), you now have the information to do so.

Keep up the good work!







HM

Thanks Hector, I knew I was in over my head with sound measurement. Comparing the readings of my bikes to the calibrated meters at events I have entered it is very close but not so much guns. I shot a hot 32-20 in the garage and it registered 85db, sounded louder to me , Richard

[HectorMedina]

Some sound meters saturate easily.

But your ears don't, so always be careful when shooting indoors. Even some airguns can yield "unhealthy" sound levels.

I am half deaf to high pitched sounds. Mostly out of PB shooting without earmuffs. Way back then, there was no real conscience about this.

Keep yourself safe and help keep others safe. Your numbers may be different from what is advertised or published, but they are still valuable.

Thanks for your work!







HM