newb question: What is doppler?
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- KVRAF
- 10597 posts since 13 Jun, 2004 from Alberto Balsam
People often ask for doppler effects here...to my current knowledge it has to do with red-shifting light sorces? what is an adio doppler effect?
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- DC TC
- 2518 posts since 30 May, 2004
taken from oli larkin's plugin description of spacestation:
The Doppler Effect is the name given to the perceived pitch change when a sound source moves past the listener. The pitch is higher as it approaches and lower as it moves further away. Examples of this are the sound of a passing train, ambulance or race car.
Spacestation allows you to apply this effect to any sound source so it's useful for sound designers or for musicians wishing to create spatial movement in their sounds/music.
The Doppler Effect is the name given to the perceived pitch change when a sound source moves past the listener. The pitch is higher as it approaches and lower as it moves further away. Examples of this are the sound of a passing train, ambulance or race car.
Spacestation allows you to apply this effect to any sound source so it's useful for sound designers or for musicians wishing to create spatial movement in their sounds/music.
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- KVRAF
- 1817 posts since 1 Jun, 2003
are you serious? (no offense intended)
iirc the doppler effect relates to the phenomenon of a sound source changing perceived pitch as it moves towards you/away from you.
(the kind of racing car 'weeeeeeeeoooooooooow' sound...
)
iirc the doppler effect relates to the phenomenon of a sound source changing perceived pitch as it moves towards you/away from you.
(the kind of racing car 'weeeeeeeeoooooooooow' sound...
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- KVRAF
- Topic Starter
- 10597 posts since 13 Jun, 2004 from Alberto Balsam
Ok so it's basically an emulation of the scientific doppler effect? Thanks, mate.
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- KVRAF
- 1817 posts since 1 Jun, 2003
OT - do you you it's definItely, not definAtely?Definately Not Chase wrote:Ok so it's basically an emulation of the scientific doppler effect? Thanks, mate.
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- KVRAF
- 3508 posts since 27 Dec, 2002 from North East England
The doppler effect happens when the source of a waveform is moving relative to the listener. Best example is when a car goes past you playing a dodgy rave tape really loud. The music is sped up as the car approaches you, then the music seems to slow down when the car draws level and drives past you.
It's basically the same thing with light, and any other waveform.
It's basically the same thing with light, and any other waveform.
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- KVRAF
- Topic Starter
- 10597 posts since 13 Jun, 2004 from Alberto Balsam
Did you know its daeslixia, not desliksyia?fabi wrote:OT - do you you it's definItely, not definAtely?Definately Not Chase wrote:Ok so it's basically an emulation of the scientific doppler effect? Thanks, mate.
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- KVRAF
- 1817 posts since 1 Jun, 2003
yeah, i did, but i don't anymore. it's alzheimer's...Definately Not Chase wrote:Did you know its daeslixia, not desliksyia?fabi wrote:OT - do you you it's definItely, not definAtely?Definately Not Chase wrote:Ok so it's basically an emulation of the scientific doppler effect? Thanks, mate.
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- KVRAF
- 2565 posts since 30 Mar, 2004 from Phoenix AZ USA
You are standing on an empty highway and car is coming.
What do you hear?
While the car is getting closer to you, the pitch of the engine noise is constantly rising, as soon as it is passing you the pitch goes lower.
All this is happening even though the car travels at the same speed and the engine emits the same constant RPM noise.
This is called the Doppler effect (I believe it was named after the scientist that explained the phenomena)
As to why is this happening it's a little hard to explain but I will try.
For the example's sake let's say that the car emits a 2Hz signal and it is standing in one spot, one mile away from you.
That means that the car is "sending a pulse", "a sound wave" (like an ocean wave)towards you every half a second.
So these waves with fixed intervals between them start to arrive at your ear, 2 per second hence you hear the pitch as a 2Hz.
But what happens when the car is not standing but rather moving towards you?
So imagine that the car sends out the first wave and then it start to run after it, by the time it sends out the second wave it actually caught up a little to the first wave and closed the gap a little (the interval) between the first and second wave.
Now you have waves with smaller intervals between then so when they reach your ear it will be 3-4 (every increasing) waves per second hitting you.
And that translates to 3-4-5 HZ , ever increasing pitch.
By the way if the car reaches the sound speed (like some jets) what happens is the gap gets closed to zero (you hear all the waves at once and that is called a "sonic boom", the thunder-like boom you hear when a concord or a fighter jet breaks the speed of sound.
Of course when the car passed you it still emits the same wave towards your ear but this time the car is running away from the waves and it is increasing the intervals between the waves , hence the pitch goes lower and lower.
Wow this must have been my longest post ever.
I hope it helps.
What do you hear?
While the car is getting closer to you, the pitch of the engine noise is constantly rising, as soon as it is passing you the pitch goes lower.
All this is happening even though the car travels at the same speed and the engine emits the same constant RPM noise.
This is called the Doppler effect (I believe it was named after the scientist that explained the phenomena)
As to why is this happening it's a little hard to explain but I will try.
For the example's sake let's say that the car emits a 2Hz signal and it is standing in one spot, one mile away from you.
That means that the car is "sending a pulse", "a sound wave" (like an ocean wave)towards you every half a second.
So these waves with fixed intervals between them start to arrive at your ear, 2 per second hence you hear the pitch as a 2Hz.
But what happens when the car is not standing but rather moving towards you?
So imagine that the car sends out the first wave and then it start to run after it, by the time it sends out the second wave it actually caught up a little to the first wave and closed the gap a little (the interval) between the first and second wave.
Now you have waves with smaller intervals between then so when they reach your ear it will be 3-4 (every increasing) waves per second hitting you.
And that translates to 3-4-5 HZ , ever increasing pitch.
By the way if the car reaches the sound speed (like some jets) what happens is the gap gets closed to zero (you hear all the waves at once and that is called a "sonic boom", the thunder-like boom you hear when a concord or a fighter jet breaks the speed of sound.
Of course when the car passed you it still emits the same wave towards your ear but this time the car is running away from the waves and it is increasing the intervals between the waves , hence the pitch goes lower and lower.
Wow this must have been my longest post ever.
I hope it helps.
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- KVRAF
- Topic Starter
- 10597 posts since 13 Jun, 2004 from Alberto Balsam
mate i know the doppler effect that happens in the real world, a la stephen hawking books i discovered in 8th grade, I was just wondering what the audio effect did and how you could use it in an audio production
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- KVRist
- 476 posts since 28 Jun, 2002 from Vancouver, Canada
I figure that combined with drastic panning, it can be useful for film-post stuff. Surround sound applications ... spatial positioning. In a musical context, I'm not sure.
~MacQ
~MacQ
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- KVRian
- 886 posts since 2 Jun, 2005 from Hawaii
i used to mess around with it in audiomulch (audiomulch's doppler effect is called "spatial" or something). audiomulch allows you to draw the path of the object, so you can sort of sync it to a tempo with some trial and error. i wish there was a free, decent, real-time doppler vst like the one in audiomulch.In a musical context, I'm not sure.
audition also has a non-realtime doppler effect, and that one is really cool because you can have it do circular stuff, like how a sound would sound if you were swinging it around your head on a string and stuff. really cool effect for percussive sounds if you get it going fast enough.
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- KVRAF
- 6504 posts since 25 May, 2002 from Bobo-dioulasso\BF__Geneva/CH
Basically the Doppler effect isn't refering only to an acoustic phenomenon
You've heard about red shift ?
Roughly :
This is refering to the spectral shift to the low frequencies of electromagnetic waves ( reds are the lowest frequencies in visible light,... that is a short bandwith of EM waves ) that are percieved from foreigh galaxies that reviels the expansion of the universe
For your guidance, ...allthough it isn't maybe useful for you !
You've heard about red shift ?
Roughly :
This is refering to the spectral shift to the low frequencies of electromagnetic waves ( reds are the lowest frequencies in visible light,... that is a short bandwith of EM waves ) that are percieved from foreigh galaxies that reviels the expansion of the universe
For your guidance, ...allthough it isn't maybe useful for you !
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- KVRian
- 520 posts since 11 Sep, 2003 from Berlin, Germany
Nice explanation, but wrong in one aspect. The change in pitch is constant while the object is moving towards you or away from you. The scenario you're describing would only happen if the car continuously accelerates. There's only a brief moment of changing pitch while the signal source is so close to you that the radial velocity of the source becomes apparent depending on the passing distance of the source.AndrewSimon wrote: Now you have waves with smaller intervals between then so when they reach your ear it will be 3-4 (every increasing) waves per second hitting you.
And that translates to 3-4-5 HZ , ever increasing pitch.
[...]
hence the pitch goes lower and lower.
"if the siren approached you directly, the pitch would remain constant until the vehicle hit you, and then immediately jump to a new lower pitch. The difference between the higher pitch and rest pitch would be the same as the lower pitch and rest pitch. Because the vehicle passes by you, the radial velocity does not remain constant, but instead varies as a function of the angle between your line of sight and the siren's velocity."
http://en.wikipedia.org/wiki/Doppler_effect