duckbill exhaust = quieter bubbles?

[reefrat]

It's a long time since I last dived with a double hose reg so I am hoping someone who currently dives one can compare it to a modern reg and share his/her opinion.

Very subjectively- do you think a duckbill exhaust valve forms exhaust bubbles with less noise than a more modern style exhaust valve?

This question relates to my casual musings on how to make scuba more "stealthy", and I guess my general interest in "vintage" equipment is based on a gut feeling that many superior concepts may have been lost in the interest of more cost-effective designs and production lines.

 

[herman]

I am not sure it's actually quiter based on audio measurements made at equal distance but from a diver point of view it is since the bubbles are not going around your head. Fish do not seem to be as bothered as much by a DH. If you want stealthy then rebreather is the only way to go.

 

[Akimbo]

We frequently switched between single and double hose within the same day on a project when I was in the Navy. I never really noticed any difference in noise level.

 

[Luis H]

My observation is that the noise level is about the same, but the location of the noise source makes a difference (to the diver and to fish that we are trying to get very close to).
Some fish I can get very close to, but other will still back off when I exhale. If I stay still, some fish will actually come up to my mask and look in (mostly in fresh water).


I have been thinking about trying a diffuser/ silencer as an "add-on" in some of my regulator projects, but it is on my list of things to do. I know basically the material I want to use, I just have to locate a source. I used to work with Navy sonar equipment over 20 years ago and there was a type of open cell foam that we used to use that I should be able to find something similar.

 

[reefrat]

Hey Luis
Let me know if you find that open cell stuff- that sounds interesting!
I agree with all the comments above and thank you for answering the question in relation to duckbill exhaust valves.
Rather than risk the wrath of the vintage fundamentalists I will discuss any further such procrastinations on another forum.
Thanks again
RR

 

[herman]

Hummmm a stealth Argo...

 

[Luis H]

Hey Luis
Let me know if you find that open cell stuff- that sounds interesting!
I agree with all the comments above and thank you for answering the question in relation to duckbill exhaust valves.
Rather than risk the wrath of the vintage fundamentalists I will discuss any further such procrastinations on another forum.
Thanks again
RR

I would not worry too much about that.



BTW, with a couple of exceptions, I don't dive with a duckbill anymore. I left a duckbill in a couple of regulators, but all my other metal can regulators have duckbill eliminators (DBE). I have not noticed any sound difference from a duckbill or DBE, but the DBE is far more convenient and it performs better than many duckbills. I have some good data that you can see in this link:
Vintage Double Hose ? View topic - DH regulator exhausts flow resistance.

I will post more stuff later.

 

[spectrum]

This past weekend I got to dive my double hose PRAM hoodless for the first time since adding the duck bill eliminator. This is very subjective but I did pay attention for a while and think it was quieter that same regulator with a conventional duckbill. Again very subjective.

With the conventional duckbill I also remember the PRAM sound being comparable to my Sherwoods with the walrus exhaust T.

Keep in mind this is coming from someone that can only hear crickets with 1 ear.:shocked2:

Pete

 

[captain]

My observation is that the noise level is about the same, but the location of the noise source makes a difference (to the diver and to fish that we are trying to get very close to).
Some fish I can get very close to, but other will still back off when I exhale. If I stay still, some fish will actually come up to my mask and look in (mostly in fresh water).


I have been thinking about trying a diffuser/ silencer as an "add-on" in some of my regulator projects, but it is on my list of things to do. I know basically the material I want to use, I just have to locate a source. I used to work with Navy sonar equipment over 20 years ago and there was a type of open cell foam that we used to use that I should be able to find something similar.

Upholstery shops that do marine seat cushions use a coarse open cell foam that doesn't hold water.

 

[spectrum]

I wonder if the air conditioner filter mesh would be fine enough to diffuse the flow? Home centers and appliance stores have that by the package.

Pete