What causes a deeper tone in a F1 can?

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mr fixit
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What causes a deeper tone in a F1 can?

Post by mr fixit »

I have read several reviews of various factory cans as well as form 1's, and have seen several mention a can having a "lower tone". I am given to understand that a can with a lower tone could seem quieter than a can with equal sound reduction having a higher tone. So my question is what causes the deeper tones? Is it anything that can be built or designed into a Form 1 can?
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RPM509
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Re: What causes a deeper tone in a F1 can?

Post by RPM509 »

I was curious about this as well, Googling it doesn't really come up with anything concrete
for me so I am going to guess and say larger volume, denser materials (heavier). I don't
think a lot of open documentation or studies have been made with this specifically, and
if any have, probably held close or proprietary information.

The larger volumes and denser materials I think would create deeper tonal qualities.
At the range, a YHM SS Phanton shot next to the same can in Ti seems to have a deeper tone,
not as tinny or high pitched, non-scientific mind you, just going by ears.
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Bendersquint
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Re: What causes a deeper tone in a F1 can?

Post by Bendersquint »

RPM is right, it is close hold and proprietary information.

You aren't going to find that information or those studies published anywhere, ESPECIALLY from a manufacturer.
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mr fixit
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Re: What causes a deeper tone in a F1 can?

Post by mr fixit »

RPM509 wrote:I was curious about this as well, Googling it doesn't really come up with anything concrete
for me so I am going to guess and say larger volume, denser materials (heavier). I don't
think a lot of open documentation or studies have been made with this specifically, and
if any have, probably held close or proprietary information.

The larger volumes and denser materials I think would create deeper tonal qualities.
At the range, a YHM SS Phanton shot next to the same can in Ti seems to have a deeper tone,
not as tinny or high pitched, non-scientific mind you, just going by ears.

I think about it like a musical instrument.....(I used to play Sax). The higher toned instruments like the alto are smaller and the air path is shorter than the tenor and more especially the bass. Same with a guitar, the smaller string vibrates at a faster frequency making a higher tone. Larger, thicker, longer strings make lower tones.
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Re: What causes a deeper tone in a F1 can?

Post by raymond- »

many factors which affect tone as you've identified. add to that, material type.
we see/hear this regularly with motorcycle canisters of similar volume but different
materials used e.g. carbon fiber, ss, titanium. (oh, B already addressed this. whoops)
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Re: What causes a deeper tone in a F1 can?

Post by jlwilliams »

I met a guy who had a F1 can that he had covered in heat shrink tubing (info stamped on the end cap). When I asked why, he said that it sounded quieter and "deeper" with the coverng than without. He figured that the tight plastic wrap had a deadening effect on the can vibrating. IIRC he was shooting 300 whisper and it was quiet.
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Re: What causes a deeper tone in a F1 can?

Post by noisecatcher »

I wonder if an individual could use something like truck bed liner to provide a deeper tone. Obviously heat and weight will be considerations. I'm curious if it would be like putting dynamat on the inside of a Honda door you can go from a Tinney sound to a thud when you close the door. It's not worth a F1 but if you are free to experiment it could be fun.
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Re: What causes a deeper tone in a F1 can?

Post by propeine »

I've not used one but do the silicone and canvas suppressor covers have any effect on the tone?
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Re: What causes a deeper tone in a F1 can?

Post by RJT »

propeine wrote:I've not used one but do the silicone and canvas suppressor covers have any effect on the tone?

I haven't tried a silicone cover, but notice no difference in sound with, or without my TAB Gear covers on.
You keep using that word. I do not think it means what you think it means.
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Re: What causes a deeper tone in a F1 can?

Post by RPM509 »

It wouldn't be practical other than for testing, but I bet a lead coating on the tube would help deaden the tone
also. Or an outter sleeve filled with sand.
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atc250r18
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Re: What causes a deeper tone in a F1 can?

Post by atc250r18 »

We've been using Lead dampening tiles and Rubber hull coatings on Submarines for decades. I can't say how many db's it reduces....but it's enough for the government to spend billions on. It's not a normal rubber it's a porous dense rubber that's extremely heavy, it works well.
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Re: What causes a deeper tone in a F1 can?

Post by destrux »

The deepest tone F1 build I ever heard was a .22lr made from sch 80 pvc pipe and coated with plastidip. I had thoughts of plastidipping my steel 9mm build, but the smell and mess when it heats up would be awful.
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Re: What causes a deeper tone in a F1 can?

Post by Meche_03 »

Most of the he methods mentioned are dampining the natural harmonic frequency of the can. Without testing I would assume a suppressor can will react and ring like a orchestra bell which is a tube suspended from one end. Longer tubes and larger diameter tubes have a deeper tone. There are nodes within the tube and that do not move while the tube vibrates. If one restricts the movement of the tube between the nodes the tube will dead pan and not ring. If one were to place a tight baffle or weld one in between 2 nodes the tube will not vibrate like a bell.

These nodes are easy to calculate in a freely suspended tube....but a suppressor is restrained on one is and and capped on the other. It should work similar to a sound tube science experiment. One end is capped and one end has a speaker. If you use propane you can drill holes along the top of the tube to jet the gas out and burn. As you change the frequency driven from the speaker peaks and valleys of flame height will show the standing wave profile....you would have to place baffles at peak areas to disrupt the standing wave.
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Re: What causes a deeper tone in a F1 can?

Post by L1A1Rocker »

Meche_03 wrote:Most of the he methods mentioned are dampining the natural harmonic frequency of the can. Without testing I would assume a suppressor can will react and ring like a orchestra bell which is a tube suspended from one end. Longer tubes and larger diameter tubes have a deeper tone. There are nodes within the tube and that do not move while the tube vibrates. If one restricts the movement of the tube between the nodes the tube will dead pan and not ring. If one were to place a tight baffle or weld one in between 2 nodes the tube will not vibrate like a bell.

These nodes are easy to calculate in a freely suspended tube....but a suppressor is restrained on one is and and capped on the other. It should work similar to a sound tube science experiment. One end is capped and one end has a speaker. If you use propane you can drill holes along the top of the tube to jet the gas out and burn. As you change the frequency driven from the speaker peaks and valleys of flame height will show the standing wave profile....you would have to place baffles at peak areas to disrupt the standing wave.
VERY interesting. Thanks for taking the time to post that information.
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Re: What causes a deeper tone in a F1 can?

Post by L1A1Rocker »

I was watching Top Gear reruns the other night and Clarkson said something that reminded me of this thread. In discussing a new supercar, Clarkson described the deep tone of this car's exhaust caused by the titanium exhaust pipes.
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Re: What causes a deeper tone in a F1 can?

Post by c5_nc »

mr fixit wrote:I have read several reviews of various factory cans as well as form 1's, and have seen several mention a can having a "lower tone". I am given to understand that a can with a lower tone could seem quieter than a can with equal sound reduction having a higher tone. So my question is what causes the deeper tones? Is it anything that can be built or designed into a Form 1 can?
Just an observation on the Form 1s I have done, that include Freeze Plugs, Valve Retainers, machined cones, and monocores. Coating the baffles (cerakote and VHT Header baked) did not appear to effect anything. Deeper and more aggressive clipping appeared to give a lower tone. Variable spacing of baffles appeared to give a lower tone (variable sizes of spacers between baffles and the case of monocores, variable and differently shaped sizes in the openings).
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