Quiz Time! - NO CHEATING
10-18-2004, 04:45 PM
#12
1000 Watt CAFz'r
Join Date: Jun 2002
Posts: 1,242
Originally posted by pepsi:
can you hear 0 db(with good hearing)
can you hear 0 db(with good hearing)
Blah...in Edmonton right now studing this subject. At least it is snowing [img]graemlins/thumb.gif[/img] I gets a head start on winter YA! (no that was not sarcastic)
10-20-2004, 07:37 PM
#13
50 Watt CAFz'r
Join Date: Mar 2003
Posts: 276
Originally posted by Livin - Loud:
dunno.... i dought it
also 3 db gain, is double the acoustic energy. a 10 db increase is double the loudness to the human ear so to speak.
Livin Loud
dunno.... i dought it
also 3 db gain, is double the acoustic energy. a 10 db increase is double the loudness to the human ear so to speak.
Livin Loud
10-20-2004, 07:53 PM
#14
194 dB is the dB limit in air at 101.325 kPa and 20 degrees celsius. At the north pole on a very cold day, it would be possible to break 200dB ( no this does not mean you would be louder there, it means the density of the air would allow for more pressure difference, allowing more force to be exerted)
Submarines sonars are around 230 dB .
Although Bell's original definition of 1 dB was the threshhold of human hearing, we now define it as
10^-12 W/m^2
Submarines sonars are around 230 dB .
Although Bell's original definition of 1 dB was the threshhold of human hearing, we now define it as
10^-12 W/m^2
10-21-2004, 12:43 AM
#15
^not sure about the cold making that much of a difference...
As I recall, its virtually impossible to break 150db in open atmosphere with a conventional speaker/driver. And at over 180db or so, a wave at STP begins to shock...
Damn- thatd be loud.. [img]graemlins/headbang.gif[/img]
As I recall, its virtually impossible to break 150db in open atmosphere with a conventional speaker/driver. And at over 180db or so, a wave at STP begins to shock...
Damn- thatd be loud.. [img]graemlins/headbang.gif[/img]
10-21-2004, 01:08 PM
#16
Can't remember the exact calcaulations, but it has to be below around -80 degrees celsius to break 200 dB. At this point, there is almost no moisture in the air and the ideal gas law (pv=nRt) exhibits very little deviation from van der waal's equation and the bulk modulus of air decreases.
This is under the assumption that a sound wave is a completely adiabatic process.
[ October 21, 2004, 07:49 PM: Message edited by: seege ]
This is under the assumption that a sound wave is a completely adiabatic process.
[ October 21, 2004, 07:49 PM: Message edited by: seege ]
