The Physics of Sound: Why No Music Beyond the Door?

[AnthreX]

i was in my room listening to rock musics with speakers and the door closed
and i went out of the room closing the door behind me and in about 7~8m away from the room i didnt hear any voices coming out of the door just the bass beats ( drums ),

why is that ?





( the door is just a wooden door )
the wall is concrete
speakers were facing the door

 

[LURCH]

Bass is a long wave, and passes through obstructions more easily.

 

[pallidin]

Bass is a long wave, and passes through obstructions more easily.

Sounds good to me.
Couldn't resist.

 

[AnthreX]

long wave means lower frequency ??

 

[LURCH]

If the waves are moving at the same speed (like soundwaevs crossibng a room), yes. Two waves cross a room, one has length L, the other's length is 1/2L. The one that is twice as long will take twice as much time to pass at the same speed. So it will have frequency 1/2 that of the other wave, making it 1 ochtave lower.

 

[TheDude710]

If the waves are moving at the same speed (like soundwaevs crossibng a room), yes. Two waves cross a room, one has length L, the other's length is 1/2L. The one that is twice as long will take twice as much time to pass at the same speed. So it will have frequency 1/2 that of the other wave, making it 1 ochtave lower.

None of this is true... If a sound wave has wavelength L and another has wavelength L/2 in the same room then they still will move at the same speed. The one with L/2 will have twice as high of a frequency. speed of sound = wavelength times frequency... and the speed of sound is pretty much constant in a constant environment nomatter what the wavelength. But the reason why you only hear bass has already been said, lower frequency (longer wavelenghts) can pass through objects better. One more this... Ochtaves are not based off doubling a frequency, and ochtave is a multiple of the base frequency of that note. If 'C' is 356, then the ochtaves of C are n*356 where n is 1,2,3...

 

[LURCH]

anthrex,
Dude apparently did not understand my post. I hope that you did, but I want to make sure. This part:

None of this is true... If a sound wave has wavelength L and another has wavelength L/2 in the same room then they still will move at the same speed. ... and the speed of sound is pretty much constant in a constant environment nomatter what the wavelength.

is exactly the same as what I said here:

If the waves are moving at the same speed (like soundwaevs crossibng a room), yes.

What I'm saying is that the wave that is twice as long will take twice as much time to pass a stationary point (like your ear drum, for example) specifically because it is traveling at the same speed as the shorter wave.

As for this:

One more this... Ochtaves are not based off doubling a frequency, and ochtave is a multiple of the base frequency of that note. If 'C' is 356, then the ochtaves of C are n*356 where n is 1,2,3...

You can research it yourself here or any number of music theory sources.

 

[TheDude710]

Sorry man, I was incorrect on Ochtaves but the way you explained the speed thing was unclear.