| Above 194 dB SPL [message #319823] |
Mon, 05 May 2008 20:32  |
 |
Michael 'Bink' Knowles
Messages: 3917
Registered: April 2004
Location: Oakland, CA |
Has No Life |
|
|
I've been wondering what sine wave energy would look like dumped into the air at greater and greater power levels to push past 194 dB (SPL) at sea level/room temperature. Does the image here have the trend right or do the compression peaks get narrower and narrower because of having only a finite number of air molecules to compress?
What kinds of sonic distortion would we see as we approach 194 dB SPL? At what level does air begin to be more radically non-linear than we're used to at 120 dB SPL?
What frequency range would distort first, lows or highs?
-Bink
|
|
|
|
| Re: Above 194 dB SPL [message #319870 is a reply to message #319823 ] |
Mon, 05 May 2008 22:19  |
 Tim Duffin
Messages: 462
Registered: September 2004 |
Has No Life |
|
|
Where did you find that graph? That is not what happens to sinusoidal energy when it approaches 2atm. The correct drawing would look like the top of the wave overtaking the bottom of the wave and forming a straight vertical line, or 'pressure front' with its slope approaching infinity. There are several reasons for this -- one being the frictional effect of the peaks increasing their temp in a fluid as they get pushed closer and closer together.
T
www.spl-sound.com
|
|
|
|
|
|
|
|
| Re: Above 194 dB SPL [message #319979 is a reply to message #319926 ] |
Tue, 06 May 2008 08:09 |
Charlie Zureki
Messages: 533
Registered: April 2008
Location: Detroit Area |
Has No Life |
|
|
If it were a sine wave it would tend to distort more as a sawtooth wave over time because of increased temp of air molecules bumping into one another. The wave would also naturally tend to travel toward cooler air from it's emission point. Frequency is also a factor.
The Higher the frequencies, the lower the threshold to distortion.
At 180dB you'd see the air "move", SHock Waves.
In any case I'd rather not be around 180dB. Weird things start to happen like ear-drums burst, internal organs, eyes, etc...
Hammer
Be prepared, you'll need it!
|
|
|
|
|
|
| Re: Above 194 dB SPL [message #320077 is a reply to message #319908 ] |
Tue, 06 May 2008 13:00 |
Tim Duffin
Messages: 462
Registered: September 2004 |
Has No Life |
|
|
It is difficult for a computer to graph spaced out vertical pulses-- but yes, that is a better approximation. A sawtooth would be the easiest thing to visualize via a line graph.
T
www.spl-sound.com
|
|
|
| Re: Above 194 dB SPL [message #320086 is a reply to message #319914 ] |
Tue, 06 May 2008 13:33 |
Charlie Zureki
Messages: 533
Registered: April 2008
Location: Detroit Area |
Has No Life |
|
|
Some Car Audio Aficionados in California have claimed over 180dB from 4 18" sub woofers. The Microphone must have been less than an inch from the port?
Hammer
Be prepared, you'll need it!
|
|
|
| Re: Above 194 dB SPL [message #320133 is a reply to message #320077 ] |
Tue, 06 May 2008 15:12 |
Iain Macdonald
Messages: 688
Registered: August 2005
Location: UK Europe |
Has No Life |
|
|
Black:Normal.
Purple:Time distortions, crest overtaking lower density regions.
Green:Temporary state.
Red:Stabilises, with sharp leading edge.
Iain.
Attachment: Wave4.jpg
(Size: 12.62KB, Downloaded 468 time(s))
|
|
|
| Re: Above 194 dB SPL [message #320147 is a reply to message #320133 ] |
Tue, 06 May 2008 15:35 |
Charlie Zureki
Messages: 533
Registered: April 2008
Location: Detroit Area |
Has No Life |
|
|
Ian,
That was great! I was looking for something to post... you got it.
Hammer
Be prepared, you'll need it!
|
|
|
Welcome to the ProSoundWeb sound reinforcement forums, home of more than 50,000 audio professionals. 
Forum Home
Login
Forum Search
Register
FAQ
