Have someone made this kind of ANC device what is physically small box with microphone and output what can be connected to car stereo?
I know AKM have AK7739VQ chips for (also) ANC: https://www.akm.com/eu/en/products/audio-voice-dsp/solution/active-road-noise-cancellation/
Are this chips available for DIY?
Or some ANC headphones can be used as source for special chips?
I know AKM have AK7739VQ chips for (also) ANC: https://www.akm.com/eu/en/products/audio-voice-dsp/solution/active-road-noise-cancellation/
Are this chips available for DIY?
Or some ANC headphones can be used as source for special chips?
The problem will be the complex sound radiation and reflection inside the cabin.
It's much easier to do that just next to your ears with a headphone.
Low frequency cancellation might be possible, however.
It's much easier to do that just next to your ears with a headphone.
Low frequency cancellation might be possible, however.
So there has to be a barrier between the noise source you want to cancel and the space where the cancelling takes place. Perhaps if the car were stationary in a noisy environment, you could pick up the sound from outside the cabin and cancel it inside. I'm not seeing that when the car is moving, engine running, tires wailing. Even how to pick up the outside sound would be quite a challenge, with airflow everywhere about a moving vehicle at ordinary speeds these days.
I look mainly for mid to bass cancellation, mainly tires noise, I know it is nearly not possible for high frequencies.
I also know cancellation can be done only in small area close to mic.
Can be that cancellation is more easy if I use special (and only one) speaker and amplifier?
I also know cancellation can be done only in small area close to mic.
Can be that cancellation is more easy if I use special (and only one) speaker and amplifier?
That would be difficult and may require 4 different systems working where the sound is entering the cabin (windows up).
Will you be replacing the tires at any point?
What about the mass-adding epdm/butyl,asphault type sound dampeners?
^^ with a layer of jute type insulation then possibly carpet over that?
Will you be replacing the tires at any point?
What about the mass-adding epdm/butyl,asphault type sound dampeners?
^^ with a layer of jute type insulation then possibly carpet over that?
This tire replacement and additional sound dampers installation is already done, effect was but I want more.
It would be good to still be able to hear all stuff going on in case the tires meet unexpected ice, gravel or oil. Hearing one owns car in all situations is somewhat useful for safety. Hearing the other cars tires when it breaks big time just before it will be hitting you can help you make the best choices.
Been in a few awkward traffic situations with silly cows wearing noise cancelling headphones while driving a car or worse a fatbike (with also no mirrors and of course the smart phone in 1 hand).
Situational awareness saves lives.
Been in a few awkward traffic situations with silly cows wearing noise cancelling headphones while driving a car or worse a fatbike (with also no mirrors and of course the smart phone in 1 hand).
Situational awareness saves lives.
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Yes, full silence is not good, but nose level about 60 to 70 dB make not possible to enjoy music.
Lifted from "avaitionstackexchange" user "leftaroundabout" - a more sophisticated understanding than I previously posted;
"Noise cancellation works precisely if, and only if, the area you try to shield from the noise is significantly smaller than the wavelength of the sound you try to cancel, because then you can ensure that the anti-sound signal will in fact interfere everywhere destructively with the environment noise. Wavelength scales as λ=csν, so it gets ever smaller as the frequency ν increases. (cs≈343ms is the speed of sound.)
As soon as the size of the room you try to apply this to is larger than the wavelength, it is inevitable that the artificial signal will in fact interfere constructively on half the space, i.e. it will in many spots actually make the problem worse than it was by itself!
In a car, you can go quite far – the space is really small, and LF rumble has a generous wavelength – up to ~100 Hz you can be sure that it at least won't interfere constructively anywhere in the cabin.
Quite different in case of an airliner – not only is the cabin much bigger, also, jet noise has much more high-pitched components. Hence it is completely hopeless trying to cancel this sound with open speakers. It is possible to cancel it directly at the ear, with noise-cancelling headphones. But these are already available individually, so it's not something the airline needs to worry about!"
Considering, it's understandable why NC headphones work as well as they do. In a car cabin, getting to 1k everywhere could be tough - unless your idea is for a solo arrangement; the driver position gets the full bandwidth cancellation, the rest of the cabin locations is what it is.
"Noise cancellation works precisely if, and only if, the area you try to shield from the noise is significantly smaller than the wavelength of the sound you try to cancel, because then you can ensure that the anti-sound signal will in fact interfere everywhere destructively with the environment noise. Wavelength scales as λ=csν, so it gets ever smaller as the frequency ν increases. (cs≈343ms is the speed of sound.)
As soon as the size of the room you try to apply this to is larger than the wavelength, it is inevitable that the artificial signal will in fact interfere constructively on half the space, i.e. it will in many spots actually make the problem worse than it was by itself!
In a car, you can go quite far – the space is really small, and LF rumble has a generous wavelength – up to ~100 Hz you can be sure that it at least won't interfere constructively anywhere in the cabin.
Quite different in case of an airliner – not only is the cabin much bigger, also, jet noise has much more high-pitched components. Hence it is completely hopeless trying to cancel this sound with open speakers. It is possible to cancel it directly at the ear, with noise-cancelling headphones. But these are already available individually, so it's not something the airline needs to worry about!"
Considering, it's understandable why NC headphones work as well as they do. In a car cabin, getting to 1k everywhere could be tough - unless your idea is for a solo arrangement; the driver position gets the full bandwidth cancellation, the rest of the cabin locations is what it is.
I am happy with only cancellation at driver position.
So technically it can be possible.
But noise cancellation must not cancel sound from audio system.
So technically it can be possible.
But noise cancellation must not cancel sound from audio system.
Maybe OEMs did not produce this devices as they not see business with it, but technically It can be done with reasonable price?
Needed parts can be get for example from https://www.amazon.co.uk/dp/B0C8SJS...p_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM
Needed parts can be get for example from https://www.amazon.co.uk/dp/B0C8SJS...p_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM
Did you ever wear noice cancelling headphones and knock on them?
That results in a very loud and not at all "cancelling" bang. Noise cancelling is a very sensitive process, similar to negative feedback, but very close to oscillation or other catastrophic events. Imagine that with several hundred watts while driving on a crowded street.
I would not like to be near you at that moment, honestly!
That results in a very loud and not at all "cancelling" bang. Noise cancelling is a very sensitive process, similar to negative feedback, but very close to oscillation or other catastrophic events. Imagine that with several hundred watts while driving on a crowded street.
I would not like to be near you at that moment, honestly!
ANC is in all kinds of cars now, and has been for years. In Hondas for at least a decade. And having one of them, I can say that I would prefer a lot of good old fashioned sound deadening/absorption instead of what they've done (or in addition to it). It's not like the car is insanely quiet because of it; it's basically just back to where things were before. I would guess most manufacturers are using it to save money and weight, not because it's better acoustically. Once there's enough computing power in the car, things like this are pretty easy to incorporate (for a car company) and don't involve much beyond the development cost.
I think you're imagining more performance than can be had with today's technologies and the limitations of the environment you are expecting it to work in. At a bare minimum, I think you'd have to wear microphones for a DIY system near your ears to get up to the frequency range you've proposed, and you'd likely still have issues due to ear spacing and the wavelength at 1 kHz.
Even in headphones with ANC, a lot of the performance relies on the passive elements that isolate the inner and outer environments.
https://carbuzz.com/car-advice/active-road-noise-cancelation-in-your-car-all-you-need-to-know/
"Jaguar Land Rover: The British marque makes use of sensors on each wheel to monitor the vibrations from the road surface as well as data gathered from how many passengers are in the vehicle, in order to play the correct opposite frequency through the speakers. According to the manufacturer, this will reduce overall noise levels by up to four decibels, and lower disruptive noise peaks by ten decibels."
I think you're imagining more performance than can be had with today's technologies and the limitations of the environment you are expecting it to work in. At a bare minimum, I think you'd have to wear microphones for a DIY system near your ears to get up to the frequency range you've proposed, and you'd likely still have issues due to ear spacing and the wavelength at 1 kHz.
Even in headphones with ANC, a lot of the performance relies on the passive elements that isolate the inner and outer environments.
https://carbuzz.com/car-advice/active-road-noise-cancelation-in-your-car-all-you-need-to-know/
"Jaguar Land Rover: The British marque makes use of sensors on each wheel to monitor the vibrations from the road surface as well as data gathered from how many passengers are in the vehicle, in order to play the correct opposite frequency through the speakers. According to the manufacturer, this will reduce overall noise levels by up to four decibels, and lower disruptive noise peaks by ten decibels."
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