Reducing the bubble noise of open circuit ?

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Since double hose vents to the back it is quieter and nice that way.

Not only vents to your back, but is worn lower down your back, thus putting the exhaust bubbles even farther from your ears.

Safe Diving,

rx7diver
 
Is there a way to post a *.wav file? I have audio from two dives comparing sound of a Poseidon Xtreme and a USD PRAM....

just can't get the file here.....
 
This is now venturing off into DIY, but it's unclear to me why exactly a 2nd stage regulator HAS to be in your mouth. Put it behind your head on a single snorkel tube, with a pushbutton purge cable to the back attached to the tube, and adjust the valve sensitivity to work in the new location.

(Yes, I'm aware of dead space in snorkels. The distance does not appear to be much greater going above the head vs behind.)



Though as far as I can determine, the real problem with long exhaust tubes is NOT the tube length, but rather that there is no way for water pressure to interact with the exhaust valve to keep breathing difficulty unchanged.

One option is an inductive design using an the exhaust as a venturi tube. This slopes upward behind the head, and yet keeps the exhaust opening at nearly equal water pressure. The bubbles will mostly tend to follow the open channels if the diver's head is in the normal level or down or sideways position, and breathing out induces a flow to pump water through the open front inlets.

kJzfznR.png

(Yay, Windows Paint!)

Difficulty: There is feedback from water flowing past the venturi openings, which may trigger freeflow and require a somewhat less sensitive exhaust. Or just don't induce/venturi at all and use a straight T connection to the side tubes, using an upward slope from chin to ears, to direct bubbles up the tubes behind their head..



Another solution is to use a flexible exhaust valve at the regulator with direct water exposure. When open, the air does not release at the valve location but must travel up two balanced and connected exhaust tubes. Meanwhile water equalizing inlet valves are used to balance the exhaust suction as bubbles rush up the tubes behind the diver's head after the diver has stopped exhaling.

4LiSYTy.png

Difficulty: this design will fill with air if the tube ends are pointed downward / upside down and make exhaling harder. This only occurs when the diver tilts their head way up or is lying on their back.

The first venturi / T-connection version is less complicated, doesn't cause problems upside down other than bubbling out by the diver's face, and only requires hanging two open-ended exhaust tubes off of the existing regulator technology.



Wow, yet another potentially profitable, patentable idea, which I am stupidly posting to the world on a global public discussion forum under a semi-anonymous handle. I am such a moron.

However I am also lower middle class and unconnected with any diving manufacturers to make such things a reality, and I also know that to make any sense, patents must be applied for individually in each country for it to be effective, so that means something like 50 patents in all the major 1st world countries, and so patents are really only workable for the wealthy, and basically a scam for lawyers to take money from poorer people...
 
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Yes, maybe that also plays a major part: the *quality* of the sound. Similar to how I'm sure my daughters' iPods can't play louder than my Merlin Music monitors, though it often seems so, and loud music emanating from their iPods' internal speakers really frays my nerves!
 
Oh and the other option known as "the handlebars" are the most stable and least complex in any orientation, with a direct water-exposed but watertight exhaust valve pressure balancer at the mouthpiece so that air is forced to migrate out through either exhaust tube.

bMbX0gZ.png


Just be careful if these are a half meter long on each side and someone is following to close beside you... you may stab them or whack them in the head with your regulator exhaust when you turn your head..
 
Bubbles totally behind me, Argonaut Kraken Series 1 with DSV mouthpiece assembly:

IMG_6874_zpsdgvgm5pk.jpg


N
 
Since double hose vents to the back it is quieter and nice that way. One issue is that if you are the kind of person that sometimes breaths inverted (head down feet up) or on your back you will notice a difference with double hose - at least the ones I played with.

I spend a fair amount of time inverted like this looking under rocks for lobsters, taking a picture, or just testing my trim weighting (I try to set myself up so that I can hang motionless vertically head-down, vertically head-up, or horizontal). Is the difference a big one with the Kraken?
 
This is now venturing off into DIY, but it's unclear to me why exactly a 2nd stage regulator HAS to be in your mouth. Put it behind your head on a single snorkel tube, with a pushbutton purge cable to the back attached to the tube, and adjust the valve sensitivity to work in the new location.
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What you're talking about is basically the way doublehose regs work. The 2nd stage is in the can behind your head, the mouthpiece has one-way valves on each side attached to the hoses. One hose brings air from the 2nd stage, one hose vents exhaust back to the cans. This way there is a complete loop and the intake/exhaust are at the same depth. The dead air space is not an issue because exhaled air goes into the exhaust hose via a one-way valve and cannot mix with fresh air from the other hose.

In the old days I would have advised you to get a DA aquamaster (probably about $150) and get it working without spending too much; then you could try it, see if you like doublehose diving, and if so, go for the phoenix nozzle and all the silicone hoses/mouthpiece/etc. But now the Kraken is available for less money than it would cost to completely re-fit an aquamaster, and you can start off with the best performance. Because they're only made on a limited production run by one small company, I suspect that the re-sale would be pretty good in the event you don't like it.
 
https://www.shearwater.com/products/peregrine/

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