What if you build a sub with helium in it?

[Tehrasha]

Aleast some of those heavy boxes would be easier to move.

[tade]

Sulfurhexafluoride is oderless and inflammable, so no problems there (could have found that out yourself btw)

Thanks for the tip. i didnt know i could learn information by myself.

[xplod1236]

Originally posted by planet10
With Helium you'd need to build a much bigger box.

dave

I'm not sure what kind of box we're talking about, but for a sealed one, you would need a smaller box.
According to the ideal gas law, "One mole of an ideal gas at STP occupies 22.4 liters." That applies for all gasses, so you would have the same amount of helium as air. The pressures inside and outside the box would be the same, but helium would be a lot easier to compress (because of the smaller molecule size) than air, which would be like having a bigger box filled with air.

the weight of helium is a factor 7 lighter then the air.

So you would get away with using a helium-filled box to get the same response as you would from a box that is 7 times bigger and holds 7 times more air.

This should be correct according to the ideal gas law, but in my mind it just doesn't seem right, and I can't figure out why.

Anybody want to add to the confusion?

[mike.e]

A guy online called MuriloP,he had a site with equations proving why in theory,a box of something other than air could prove useful I forget what it was.

What about loosely filling a gastight thin bag with gas inside the box?

One or two companys have done it commercially.

[rcavictim]

Originally posted by Rademakers
Sulfurhexafluoride is oderless and inflammable, so no problems there (could have found that out yourself btw).


Wkr Johan

Due to a quirk in the english language, there are many, both words flamable and inflamable mean that the substance will burn. Non-flamable, or uninflamable mean no fire. I'm not sure if unflamable is a real word. The meaning seems to be clear though if it is. No fire.

[ralphs99]

In the 70's Cerwin Vega made a system with a Nitrogen filled bladder inside the box.

Cheers,
Ralph.

[jadenlinkletter]

i'd say this calls for a project,

if anyone has any useful information.
links,
specs,
company,

post your info.

thanks,

[Rademakers]

i didnt know i could learn information by myself

Meditation perhaps would do that for you, however you could have checked with Google first

Due to a quirk in the english language, there are many, both words flamable and inflamable mean that the substance will burn. Non-flamable, or uninflamable mean no fire. I'm not sure if unflamable is a real word. The meaning seems to be clear though if it is. No fire.

Thanx for the pointer

Non-flam(m)able it is.

Wkr Johan

[phase_accurate]

Re pressurizing box:

Apart form causing problems with coil displacement and challenging a driver's mechanical rigidity it would only do one thing: make the air-volume "stiffer". I.e. it would rise the in-box resonance frequency (fc) of the driver which you don't want - I assume. This effect can be had much cheaper by using a smaller box from the beginning !


Re articifially increasing the internal volume:

There was once a closed-box speaker model by Cerwin Vega (late seventies beginning of the eighties) that had a bag inside which was filled with some inert gas to achieve exactly what is discussed here.
Apart from that I once read about using some stuff that easily changes between fluid and gaseous state at room temperature to achieve the same.

Regards

Charles

[SY]

SF6 is indeed non-toxic, inert, non-inflammable, and dense. It does have one disadvantage- any sparks or arcs will cause it to break down into some VERY toxic components.