Hsu Hribr Subwoofer System?????

[MACCA350]

I always thought there was a limit to how many DB could be reached in our atmosphere(just under 200db rings a bell) and above that it become something like pressure waves like explosions. Something to do with our air pressure or something like that. BTW don't quote me on any of this, maybe someone else has heard this.

cheers

 

[MACCA350]

Found this at Wikipedia

In air at atmospheric pressure, the simple relationship between pressure and power of a sound wave breaks down for pressures on the order of or greater than 1 atmosphere, which corresponds to an SPL of 194 dB re 20 µPa (i.e. 20 log10 atm/20 µPa) = 194.09). Waves with higher pressures are more properly called shock waves rather than sound waves; their properties are very different from those of normal sound waves. One could extend the meaning of sound pressure level in order to describe the pressure waves emitted by processes such as earthquakes and explosions, and get numbers exceeding 194 dB, but these numbers should only be used if it is clear how the measurable quantities are converted into SPL. An extensive list can be found at makeitlouder.com.

So what actually changes above 194db?

BTW here is the 'disclaimer' for the makeitlouder site

Decibel’s ( db ) are units of ratio’s and in this table are expressed in atmospheric decibels and in this table are REPRESENTATIVE OF THE OBJECT (N), and not neccesarily what the listener or sound level meter experiences (P)

cheers

 

[mike c]

so what subwoofer produces these so-called SHOCK WAVES? I want to feel the 'Sauron dying' shockwave from LOTR!

how high in SPL did the mythbusters get with their brown note episode?
how high in SPL is dangerous to a houses structural integrity? the wife keeps asking and I keep telling her my subs aren't doing any damage to the house.

 

[Tomorrow]

Off in another arena that touches on this issue is the matter of how certain frequencies, particularly in the subwoofer range, affect brain activity. Assuming my research-psych courses were accurate from soooo many years ago, and that the data is still relevant.....we were taught that 22 hz is the average frequency measured from a sleeping human brain.

Here's a newer breakdown on the frequency response:

CLASSIFICATION OF BRAIN WAVES:
K COMPLEX – measures at 33 and above cycles per second, a state of very high anxiety.

HIGH BETA – 23 – 33 cycles per second, a very tense state in which it is difficult to e rational.

BETA – 14 – 22 cycles per second. It is the awake-state of physical alertness when the mind and emotions respond to the senses. It is associated with tension and striving.

ALPHA – 7 – 14 cycles per second. In the alpha state a person is deeply relaxed with the mind completely awake. (I call this state the “golden state” - this is as good as it gets. In this state you change your world, you make your dreams come true and you change yourself).

THETA – 3.5 – 7 cycles per second. The state for night-time sleep. Everybody experiences theta twice every normal day – when falling asleep and when waking up in the morning.

DELTA – measures at 0.5 – 3.5 cycles per second. Delta is profound sleep. Dreams take place in delta, as well as regeneration and cell renewal.

And check this out from brainsync.com...brain responses to resonant frequencies. Experimenting with this stuff might be more fun than '60's psychedelics!
http://cellphonesafety.wordpress.com/2006/10/02/how-do-sound-frequencies-affect-the-brain/

 

[majorloser]

Found this at Wikipedia

So what actually changes above 194db?

BTW here is the 'disclaimer' for the makeitlouder site


cheers

You are correct. At that level it is really a shockwave. I think it has to do with compression of a gas when the level gets over 1 atmosphere (?). The db numbers are just calculations of energy released.

But still, wouldn't it be nice to know you had a subwoofer capable of developing a shockwave?

(The Mythbusters "brown note" episode was funny)