Car Audio Central - Ultimate Car Audio Forum and Community

My roomate (who doesnt kno a whole lot about car audio) tried telling me that he saw a video of someone w/ a single 18" hitting 180's. I find that very hard to believe.

TEDD

ridr4lif wrote:My roomate (who doesnt kno a whole lot about car audio) tried telling me that he saw a video of someone w/ a single 18" hitting 180's. I find that very hard to believe.

TEDD

That's because it's not true

Sounds unlikely, but i guess anythings possible 'eh?

Not anything..like i said atmospheric conditions will only allow around 180 db's if i recall correctly...AND if he were to hit this number..i'm gunna have to say it was on the AC..not the TL..and still..I doubt it happened. I could be wrong.

They probably used a computer mic and put the sub right on top of it.

William from NOLA wrote:They probably used a computer mic and put the sub right on top of it.

lol..wouldn't doubt it!

Lol, wouldn't doubt it... seems to be the only way to get 200...200 Is a little out there, and like stated above our atmosphere doesn't allow it... (Audiobass10).

depends how you were lissening to it, as volume is measured as preasure level then if you played an 18" sub into a small enough area then it could be possible to hit 180db from 1 sub but you'd need to play it into an area almost as small as the enclosure it's self. Ever lightly tapped the end of an rta mic with your finger ,and checked the spl level gained ( not recomended but it was a spare one at work so no harm done ) back to highest spl ,I think there was a green van from juggernaught that claimed to hit 180.1 db but it was in one of the bull***t moddifying mags from the UK so probably not

audiobass10 wrote:Actually, 200db will never be recorded in any audio system, because of atmospheric conditions. Not sure on the exact number, but i believe the atmosphere can only support somethin in the 180db range..somone correct me if i'm mistaken.

I've not heard of this before and no one has yet to give any concrete explanation/support for this argument.

My understanding is that dB is another way of expressing the intensity of sound waves, which is in the SI units of watts/m^2.

dB = 10 x log (I/IR)

where I is equal to the intensity of the sound wave in question and IR is the reference intensity of the softest sound wave that the human ear can percieve (equal to about 1x10^-12 w/m^2).

But I do not see how the "atmospheric conditions" can limit the sound waves to a certain maximum amplitude.

"But I do not see how the "atmospheric conditions" can limit the sound waves to a certain maximum amplitude."

The loudest sound level that can exist is determined by atmospheric pressure. A sound wave is compression (pressure increase) and rarefaction (pressure decrease) of air (or the medium you're trying to compress, anyway), so the SPL you can accomplish is limited by the actual pressure of the atmosphere. Don't think of it in terms of pressurizing air in the method of compression, think of it in terms of pressure decrease for a second, it is impossible to create a pressure less than zero (which would be a vacuum), so it limits max pressure change to that of the atmosphere that you are creating sound in. This is why SPL changes drastically with elevation and air density, it is due to the atmosphere that it is in. When you deal with super high SPLs, you are so close to the level of the outside world's atmospheric pressure that the air is reaching it's limits of compression, that is why it is considerably harder to add a db after a certain point. Through logarithmic calculations, 194db is the maximum amount of pressure that you could possibly create in the earth's atmosphere (at sea level). The only way that you can increase SPL beyond this would be to create sound in a pressurized atmosphere, which would be below sea level, underwater, or in special cases such as space shuttles and explosions, which change the property of air due to the gases that they put out, making air more dense.