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Discussion Starter · #1 ·
I plan to add a good bit of sound insulation once I find a 17-18 car.

Anyone know how that will affect the active sound cancelling. Is the system tuned for certain frequencies or does it work like my Bose headphones and just kill noise full stop??
 

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Discussion Starter · #2 ·
Yeah thought that was a tricky questing. Will go do some research and see what I can find out
 

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If you go for sound deadening that eliminates rattling (e.g. Dynamat) then you can eliminate the resonant frequencies I.e. the lower frequency buzzes/tings the car can have caused by vibration/resonance, primarily exhausts etc.

Sound insulation will normally dampen down background noise so it reduces road noise from tyres, the engine etc.

Active sound cancelling will rely on electronics and therefore is frequency specific and usually programmed in to the processor doing the noise cancelling.

Depending on what you are trying to achieve may mean you'll need different products.
 

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"active" sound cancelling implies that it is listening for and responding to the changing sounds as the car is driving, I expect similar technology to noise cancelling headphones. If you add sound deadening you are going to affect or reduce the sounds that the system will be responding to... in fact Nissan describe it as
Active Noise Cancellation technology uses a microphone in the headlining to identify undesirable low-frequency engine sounds and neutralise them with sound waves of the opposite frequency. The result – a quieter driving experience that still preserves the invigorating sounds of the engine.
so that would fit with my expectation.
 

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Discussion Starter · #5 ·
Thanks lads,

Reason I ask. I added sound insulation to my F90 M5. Rear first, but then the front became really annoying, road noise drone. I then did the front which pushed the noise to the rear again. I added more to the rear but never had much success. It was probably down to the worn rear tyres in the end.

It seemed like the front and rear were cancelling each other out until I started messing with adding sound insulation.

As said "active" would suggest If I add sound insulation it can only help. I hate road noise and the roads I drive on are very poor. Covered in that "top dressing" every year which is very noisy
 

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Dynamat and the other brands do quieten down exhaust noise (under rear seats and boot area etc) but is really more for car-hifi where low resonance frequencies "excite" the car and cause the buzzing/ringing noise. Used to use that (and concrete, yes you read that right) in the competition ICE installs we used to do back in the day. Every object has a resonant frequency and with a car there will be a frequency (low hz) where it vibrates heavily (some variation between metal, glass etc) but basically a point where it is worst. Tune your bass to this frequency and you get extra decibels for SPL. Lower you can get it, the better (deeper the bass).

But back on topic 😂 for removing road/tyre noise, insulation is best. I find the bitumen pads are rubbish but you can still get decent product from Stinger and the like that works alright enough 👍
 

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Discussion Starter · #7 ·
Yeah I will deffo install sound insulation. Like you i find the bitumen still of limited value for what I want to achieve

Done loads of cars (i always moan about road noise) and found the most effective way is to insulate under the arches on the outside. Pretty easy as well.
 

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Know the difference between sound and vibration dampening that’s the key. You need totally different products for each although there is some overlap. The biggest thing for sound it mass. You need mass to damper and absorb sound. Dynomat and lost car audio products are not for sound they are for vibration (sub woofer making the car vibrate).

Mass loaded vinyl is great for sound.
 

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Discussion Starter · #11 ·
bttt so what would you recommend for both?
there is no noticeable difference between any of the sound deadening mats or closed cell foam. I have tried loads. Mass loaded vinyl is good but you must cover all areas with no gaps or the noise / sound will find a way through. Use all 3 for best results. I use sound deadening mat and closed cell foam on the wheel arches (outside) with good effect. I intend using the same on the inside and maybe mass loaded vinyl as well
 
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