Pneumatic sub

[GemaRastem 10+ year member]

I'm an engineer for a hydraulics testing facility. My coworkers and I were talking about subs and the mythbusters episode came up about the sub being driven by the car. We of course came up with the idea to make a hydraulic sub. We then figured that we couldn't get a hydraulic cylinder or valve to switch at anything over 20 hz. So we did some calculations with pneumatics(air) and figured out that we could definitely get over 20 hz. So I think this week/weekend we are gonna try to get a design drawn up for a pneumatic subwoofer. I have no idea how I'm gonna design a box for it, but i'll figure it out. probably have 1inch xmax, 15" cone, 2500 psi, probably run around 25 hz. I dunno if it would be competition legal, it should be loud and sound like ***, but it'll be fun.

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[cardinalsfan 10+ year member]

i wish i was smart...

 

[Lowjacker 10+ year member]

post lots of pics of your adventure

 

[JimJ 5,000+ posts]

1"? Bah, get at least a foot of P2P to make the exercise worthwhile //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[wilzyx 5,000+ posts]

my *** cheeks have 1" excursion when i fart, you gotta do better than that!

 

[AJ²06 5,000+ posts]

OOOh this so sooo baddass!! I wanna be a geniuos... well... have a higher IQ. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[AJ²06 5,000+ posts]

my *** cheeks have 1" excursion when i fart, you gotta do better than that!

//content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif//content.invisioncic.com/y282845/emoticons/ban.gif.ce8465566702ef9f72e97e794ed1c86a.gif//content.invisioncic.com/y282845/emoticons/plthumbsdown.gif.d7966af824c93c6021d1aae1778b1c19.gif Dirty...

 

[cleanerupper 10+ year member]

my *** cheeks have 1" excursion when i fart, you gotta do better than that!

Your sister gives me 1" of excursion //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif :naughty:

 

[GemaRastem 10+ year member]

We are gonna have to do some testing first, but 1" is a pretty reasonable P2P. I want to be able to run it over 20 hz and as you get a longer stroke, the harder it is to run a decent cycle rate. did some calculations. 300 watts is equal to about 30ish psi after weight compensation when using a 1" stroke, .25" bore cylinder. We will be using 2500 psi, probably abut 88% efficient.=22000ish watts equiv. with no **** impedence rise, thermal concerns, or bigger alternators/shit ton of batteries.

 

[wilzyx 5,000+ posts]

Your sister gives me 1" of excursion //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif :naughty:

ok, so your erection is 1" long and it goes back and forth in and out of your own body?

 

[snoopdan 5,000+ posts]

lol, this is funny....you of course realize that your subwoofer will cost over $5000 and weigh 400 lbs, probably 100 of those lbs would be hosing, wire and fluid...then the structure for the piston might even be more weight than that. So good luck, im guessing about $80,000 in R&D on that one.

 

[cleanerupper 10+ year member]

ok, so your erection is 1" long and it goes back and forth in and out of your own body?

wanna see it? //content.invisioncic.com/y282845/emoticons/naughty.gif.94359f346c0f1259df8038d60b41863e.gif :naughty:

 

[95stroked1500 10+ year member]

for it to be legal at a comp-

1.- has to be an available production sub for sale

2.- has to be powered by standard audio equip.

for it to be cool and a crowd pleaser... anything goes!

hydraulic sub has been done many, many years back. if i remember the story right from the speaker engineer from europe who did it, i think they did a 48" sub +/- for a movie or some effect in one.

1/2" xmax = 1" linear P2P. and 22,000w equivalent @ 25hz i imagine will slam your cone to the end of it's stroke in a bad way.

in your calculations for 300 electrical watts, did you figure in efficiency? that on a good day 300 electrical watts only equates to 3 acoustical watts with a decently efficient speaker?

 

[BassAddictJ 5,000+ posts]

wow.....i wanna see where this goes

BUILD IT! and yes a lil more excursion woudl be niftty //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[packerfan 10+ year member]

I'm an engineer for a hydraulics testing facility. My coworkers and I were talking about subs and the mythbusters episode came up about the sub being driven by the car. We of course came up with the idea to make a hydraulic sub. We then figured that we couldn't get a hydraulic cylinder or valve to switch at anything over 20 hz. So we did some calculations with pneumatics(air) and figured out that we could definitely get over 20 hz. So I think this week/weekend we are gonna try to get a design drawn up for a pneumatic subwoofer. I have no idea how I'm gonna design a box for it, but i'll figure it out. probably have 1inch xmax, 15" cone, 2500 psi, probably run around 25 hz. I dunno if it would be competition legal, it should be loud and sound like ***, but it'll be fun.

What company? Actuant?