[usc goose]

just curious. maybe there are some physics people in the house that would know. i've been reading up on cars that can push 170+ dB. and those are cars. so i was wondering what the loudest sound system known to man can push. and i was wondering if there's a point (maybe something to do with the density and composition of the air or something) where it's just not possible to get any louder.

so if anyone knows anything about anything i'd be glad to hear it. thanks.

 

[Wmcmanus]

Hi Goose. I just did a Google search on "sound pressure level" and learned... "200dB is 50 lbs of TNT detonated 10 feet away." Lord have mercy on the idiots who listen to distorted bass in their cars at 170 dB!!!

BTW, when you do a Google search these days, you need to immediately go the 2nd page of the 'hits' because the first page is filled with advertising crap. There are complex mathematical formulas provided at the Stanford.edu site which are used to determine SPLs.

Stanford SPL site

Perhaps someone can explain the math.

 

[binary_digit]

You think tnt at 10 feet would be loud, just think of a star going supernova at 10 feet disregarding the whole vacume of space thing.WOW

 

[usc goose]

well i understand the math. it just shows that spl is measured on a logarithmic scale with respect to the lowest measurable level defined as a constant.

i was just wondering if physics came into play. or if it is possible to say, have a 500 dB sound system with the right amount of cash and technology.

 

[zbuddah]

You know I've always dreamed of a system of that sort something that could push out insane amounts of spl, but the thing was it had to be hidden.

i'm always thinking like what if i had a crazy system that could push large amounts of spl but i could have the ability to direct it anywhere i want it to. Like those punks who blast thier bloated bass music who are parked right behind me at the light. With the press of the button my trunk could pop open showing an amass of subwoofers all directed right behind me at the inconsiderate punks and just blast them with pulses of deep spl drowning out their music. muahauhuahuhauhuahuahuh aye my wild thoughts get ahead of me all the time...

 

[Lando]

Quote:

Originally posted by binary_digit You think tnt at 10 feet would be loud, just think of a star going supernova at 10 feet disregarding the whole vacume of space thing.WOW

Well, if a star went supernova ten feet away, it wouldn't be a vacuum anymore, now would it?

Not ten feet away, or ten million, for that matter.

 

[lethoso]

A 500db soundsystem would theoretically be possible, but the amount of power it would consume, and the force the driver would have to withstand would render it impossible.

However, at pressures higher than atmospheric, it would be much easier, i think.

edit: also, i'm not sure if there are any of the more complicated physics which would prevent this from working.

 

[gerG]

Assuming that your are refering to reproduction of music signals, there is at least one limit that pops to mind. Since we are talking sine waves, the pressure variation should be symmetric for accuracy considerations. I don't know what limits the upper side, but pressure can't go below 0 psia. Assuming sea level operation (SL-SPL

) I get a theoretical limit of 191 db before clipping sets in. Not that most of those guys care about distortion. Please check my math.

Limits for transient sounds, single sided fluctuations, or pressure fluctuations inside a pressurized vessel would be much higher. Usually structural limitations are the main barrier.


gerG

 

[usc goose]

yeah... all of what you just said? i didn't understand none of it.

but thanks for the input.

(anyone want to translate?)

 

[Strogian]

Translation:
Here's a sound wave:
Quote:

What it represents is the air pressure at a point rapidly going up and down, centered around 1 atmosphere of pressure, assuming you're at sea level. There may be no limit to how high the pressure can go (but then again there might be, you'd have to know a lot about particle physics theories to know this), but the lowest you can go is 0. So the loudest sound you can make would be an oscillation between 2 atmospheres and 0 atmospheres .. anything past that, and the low end of the wave would get "clipped off" at 0. And according to gerG, that point is 191dB.

I don't actually know anything about this btw, I'm just translating.

 

[usc goose]

ohhh... i get it now.

thanks

edit, so i guess you'd then need a system capable of creating a negative pressure vacuum in an open space to go any higher. that'd be nuts. but then i guess you could create an airtight enclosed space and oscillate between positive and negative pressure and drive up the spl even more. i'm guessing that might cause some hearing damage though.

 

[stereth]

Here's a few numbers to try. From what I know, a doubling in apparent volume is a 6dB increase in SPL, which requires 4x the power. So each 6dB you gain requires quadruple the power from the amp.

wmc, I believe goose was referring to this article . Now apply the quadrupling power rule and try to get to 500 dB, or even 200, nevermind the equipment you'll ruin.

Edit: gerG, would that 191 dB be the change in pressure between 2 atm and 0 atm, or between 2 atm and 1/2 atm?

 

[usc goose]

actually that's the first time i've heard of that article. great read though. thanks

 

[Chinchy]

I dunno if you all saw this article a while back, but here's another interesting application for high dB--refrigerators! I think they mentioned 173 dB for this application. And it won't hurt your ears either.

http://news.bbc.co.uk/1/hi/technology/2543085.stm

 

[eatmoreplant]

Hi,
I was watching Discovery channel and there's one drummer who listened to loud sound for too long and develop tinnitus. The tinnitus cause him to hear a high frequency screeching sound like someone scratching nails over a surface. He then cut off the nerves of his ear. He prefer being deaf than to hear the screeching sound. What a sad story...