a stoner idea..hehe
Thread Starter
Super Hoser
Joined: Aug 2002
Posts: 1,184
Likes: 0
Rep Power: 301 
a stoner idea..hehe
stoner ideas..hehe
ok, i was bored so i started thinking....
a lot of you prolly know how active noise cancellation headphones work....
what if we took that concept and applied it to the inside of a car?
very basic noise cancelation involves using a microphone to record ambient noise, inverting it, then replaying it on speakers to cancel out the ambient noise...
on top of the basics are ways to preserve noise that shouldnt be canceled...
i think noise cancelation is usually applied to reduce low frequency noise. i guess stuff like road noise should be do-able?
how well does it work when active noise cancelation is applied to higher frequency noise? does it work? it would be nice to be able to make someone in the car shutTFup when we dont feel like listening
ok, i was bored so i started thinking....
a lot of you prolly know how active noise cancellation headphones work....
what if we took that concept and applied it to the inside of a car?
very basic noise cancelation involves using a microphone to record ambient noise, inverting it, then replaying it on speakers to cancel out the ambient noise...
on top of the basics are ways to preserve noise that shouldnt be canceled...
i think noise cancelation is usually applied to reduce low frequency noise. i guess stuff like road noise should be do-able?
how well does it work when active noise cancelation is applied to higher frequency noise? does it work? it would be nice to be able to make someone in the car shutTFup when we dont feel like listening
Diamond Member
Joined: Feb 2005
Posts: 1,278
Likes: 0
From: So Cal
Rep Power: 0 Benz does that in their car, but heres the problem with it.
The problem is the road noise and everyday city and driving noise has a different frequency. To be able to listen and then immediately send out the 180degree countering frequency wave would require something to move and calculate very very fast. Not to mention by the time the calculation is done and emitted through the car stereo you would have moved away from the sound.
Now I think what benz did was they took frequencies that were in the low and high range that could be considered a disturbance. A constant bunch of frequencies not related to voice or police sirens yadda yadda and programmed the car to emitt it full knowing it would block out important sounds but would take care of anything in the ranged it was programmed to. (kinda get it? Hard to explain)
The problem is the road noise and everyday city and driving noise has a different frequency. To be able to listen and then immediately send out the 180degree countering frequency wave would require something to move and calculate very very fast. Not to mention by the time the calculation is done and emitted through the car stereo you would have moved away from the sound.
Now I think what benz did was they took frequencies that were in the low and high range that could be considered a disturbance. A constant bunch of frequencies not related to voice or police sirens yadda yadda and programmed the car to emitt it full knowing it would block out important sounds but would take care of anything in the ranged it was programmed to. (kinda get it? Hard to explain)
Thread Starter
Super Hoser
Joined: Aug 2002
Posts: 1,184
Likes: 0
Rep Power: 301
Originally Posted by Boggie1688
Benz does that in their car, but heres the problem with it.
The problem is the road noise and everyday city and driving noise has a different frequency. To be able to listen and then immediately send out the 180degree countering frequency wave would require something to move and calculate very very fast. Not to mention by the time the calculation is done and emitted through the car stereo you would have moved away from the sound.
Now I think what benz did was they took frequencies that were in the low and high range that could be considered a disturbance. A constant bunch of frequencies not related to voice or police sirens yadda yadda and programmed the car to emitt it full knowing it would block out important sounds but would take care of anything in the ranged it was programmed to. (kinda get it? Hard to explain)
The problem is the road noise and everyday city and driving noise has a different frequency. To be able to listen and then immediately send out the 180degree countering frequency wave would require something to move and calculate very very fast. Not to mention by the time the calculation is done and emitted through the car stereo you would have moved away from the sound.
Now I think what benz did was they took frequencies that were in the low and high range that could be considered a disturbance. A constant bunch of frequencies not related to voice or police sirens yadda yadda and programmed the car to emitt it full knowing it would block out important sounds but would take care of anything in the ranged it was programmed to. (kinda get it? Hard to explain)
any idea of what's the highest frequency at which noise cancelation is still effective? i still think it would be cool if it was possible to make a bitch shut up
Last edited by turboslug; Mar 29, 2005 at 01:32 AM.
Diamond Member
Joined: Feb 2005
Posts: 1,278
Likes: 0
From: So Cal
Rep Power: 0 Its not that it won't work...its just that its too hard to guess what freq you want to block out and what you want to accept. Ok you know what the dopplar effect is? As you a sound approaches you its a higher tone, when it pass you its normal, and contiunes away from you its a lower tone. The computer can't predict things like that so basically it has to calculate at every second, and with say a train thats moving toward u at a fast speed the computer can't caculate that fast to keep up. Its bascially a pointless piece of technology.
Not only the fact that the computer doesn't know how to differntiate between a car horn, or a police siren, if it really did block it out then a horn and police siren would be rendered uselss, and because of the dopplar effect you can't preprogram the computer to not block out the sound.
I'm not saying it can't be done, of course it can. But it won't be cost effective and be very costly to the end user. But if u want it you can really have it. Might not work so well though.
Not only the fact that the computer doesn't know how to differntiate between a car horn, or a police siren, if it really did block it out then a horn and police siren would be rendered uselss, and because of the dopplar effect you can't preprogram the computer to not block out the sound.
I'm not saying it can't be done, of course it can. But it won't be cost effective and be very costly to the end user. But if u want it you can really have it. Might not work so well though.
Thread Starter
Super Hoser
Joined: Aug 2002
Posts: 1,184
Likes: 0
Rep Power: 301
Originally Posted by umysugarmami
that would be so awesome... some1 should make a DIY for that... i wonder how much money some1 would have dump into a project like this to make it work... 
will cost you maybe a buck or two..lol
that'll prolly work only on low frequency sound with long wavelengths..
it also gets more complex if you dont want to cancel all the noise
Diamond Member
Joined: Feb 2005
Posts: 1,278
Likes: 0
From: So Cal
Rep Power: 0 A better application for this is a computer, especially for those who have lots of fans. I wanted to do this for my comp awhile back but never got around do it. Your fans always spin at the same rate soo the freq coming out should stay the same.
Thread Starter
Super Hoser
Joined: Aug 2002
Posts: 1,184
Likes: 0
Rep Power: 301
Originally Posted by Boggie1688
A better application for this is a computer, especially for those who have lots of fans. I wanted to do this for my comp awhile back but never got around do it. Your fans always spin at the same rate soo the freq coming out should stay the same.
fan stays off 90% of the time and the new hitachi hdd's are just about dead silent
i still think it would be cool if i could do noise cancelation as a joke...ie. when i'm driving, i can all of a sudden flick on a switch to shut someone up..heh.. just for a joke...
Thread
Thread Starter
Honda Civic Forum
Replies
Last Post
kenji4862
Archive - Parts for Sale
1
Apr 26, 2005 01:17 PM
