Physics question

[Raion]

So what I mean is that most amplifiers and sound devices are to a point of producing a sound that sounds good enough to your ears. Can it be better? Why yes, there are those stereos (amp and speakers) that do sound better, but if the room is crap then the sound will also deteriorate because of the room.

In normal hearing though, it can be heard -- depending on how good your ears are, and all ears are different. What does not bother you with the sound -- may make a sound engineer -- cringe hearing how you listen to music.

The human factor is also considered when music is made -- and already there is an equalization curve that goes into all recordings -- simply to compensate for human hearing.

Then there is the artist's creativity of the sound also, and all that goes into the CD -- then it is played by your system.
Crappy system -- crappy sound. Good system-- good sound!
It all depends on the person listening to the music though in the end!
And some people have 'tin' ears and others have 'golden' ears!
The sound is all electromagnetic waves though, just like anything else!

[KrazyHorse]

The sound is all electromagnetic waves though, just like anything else!

I dispute your statement.

[Raion]

Speakers are electromechanical devices that convert electronices to air movement. But everything in this Universe according to Einstein is an electromagnetic wave. Gamma rays are electromagnetic -- radio is electromagnetic -- low sound like Earthquakes are still -- electromagnetic waves. In an stereo system the electricity amplifies the sound so the speakers become a piston producing -- a air wave that hits you. Is it possible to cause an air wave to change the weather or produce an earthquake?
Yes -- but you need a lot of power to amplify the signal recoreded.

Try the new whatever it is called by the govenment -- the sound out of the LRAD can be heard -- miles away (or at least a mile is what I read).

In the end though -- everything in this Universe is an electromagnetic wave -- and the Universe is the interaction and reflections of all those waves. Other than that -- there may be matter also -- which they are working on.

But X-rays are electromagnetic waves.

It is just the frequency of the wave is different, and humans only hear from around 15Hz up to perhaps 18,000Hz and if really good when you were young -- perhaps 20,000 Hz. Of course the bumble bee -- hears above that sound and so does a dog. Ever wonder why you can not hear a dog whistle - but the dog can?
It is above what sounds you can hear!

But not for the dog!

[KrazyHorse]

But everything in this Universe according to Einstein is an electromagnetic wave

Untrue

Gamma rays are electromagnetic

Right

radio is electromagnetic

Right

low sound like Earthquakes are still -- electromagnetic waves

Wrong

everything in this Universe is an electromagnetic wave

Wrong again

X-rays are electromagnetic waves

Right

Gammas, X-Rays, ultraviolet, visible light, infrared, radio, microwave are all part of the electromagnetic spectrum. They are propagating transverse waves with an electric field component and a magnetic field component. By Maxwell's laws, they propagate at the speed 1/sqrt(mu0epsilon0) = c = 3*10^8 m/s in a vacuum



Sound waves (including those in earthquakes or coming out of your stereo) are longitudinal pressure waves. They do not propagate in a vacuum at all. They don't have transverse electric and magnetic field components because they're not electromagnetic waves.

EDIT: damnit, forgot infrared in my list

[Kuciwalker]

Originally posted by Az
As with any other wave, there should be interference, both constructive and destructive. Frequencies shouldn't be altered during this interference IIRC.

You can. Sound waves don't add linearly.

[KrazyHorse]

Yes they do.

[Kuciwalker]

The compressed air at the peak of the wave is a slightly different medium than the air at the troughs.

[Kuciwalker]

You can get "crosstalk" between different frequencies of sound waves because of this (and because the speed of sound is dependent on frequency and the medium).

[KrazyHorse]

That's a second-order effect, dude. Non-linearities show up whenever you push a model too far. The pain threshold for the human ear is 120 decibels, which corresponds to a pressure differential of 0.02 kPa (1 atm = 101.3kPa)

[KrazyHorse]

Originally posted by Kuciwalker
the speed of sound is dependent on frequency

Not really. It's remarkably constant.

You're describing parts in 10^5 or greater here, man.

[Kuciwalker]

That's a second-order effect, dude.

True. It came up in some of the research I saw at the Naval Surface Warfare Center this summer though.

[KrazyHorse]

If it doesn't show up in first order, it's not important.

^Physicist^

[Kuciwalker]

[Kuciwalker]

http://troi.cc.rochester.edu/%7Etchau/germanium.pdf

[KrazyHorse]

Saw that 5 years ago. Along with Britney's guide to semiconductor physics. Definitely a classic, though...