cabin noise
Posted: Thu Jul 16, 2020 6:59 pm
by Johns
Would like to try and quiet down inside noise. Anyone have ideas what is the best thing to put on the inside firewall.
John
Re: cabin noise
Posted: Thu Jul 16, 2020 10:21 pm
by peter anson
I spent a lot of time trying things out and nothing was very effective. Here’s a link to my report on the Sonex Australia site https://www.sonexaus.org.au/galleries/building-tips/cockpit-noise/ so that’s a list of what didn’t work, or at least not very well.
Since doing those flights and that report I have also tried muffling the engine a bit better. The mufflers were only little “hot dog” absorption mufflers on the tail pipes but didn’t really make any measurable difference in the cabin.
Peter
Re: cabin noise
Posted: Fri Jul 17, 2020 7:32 am
by GraemeSmith
Bose A20’s - but on your ears - not on the firewall. 
Said with a smile.
YMMV
Re: cabin noise
Posted: Fri Jul 17, 2020 8:13 am
by BenCharvet
I’m also using the Bose A20’s, and I agree with Graeme. At my age I need all the help hearing I can get.
Re: cabin noise
Posted: Fri Jul 17, 2020 8:38 am
by peter anson
I have Bose A20s and agree that they work well but when I talk on the intercom to a passenger the microphone does a great job of picking up the cabin noise so that I am talking over a roar, which was the reason I was originally trying to reduce cabin noise. I have a Flightcom 403MC intercom connected to a Microair radio. If anyone has any advice on reducing that roar I would love to hear it. I have tried different mics on other headsets but no improvement.
Peter
Re: cabin noise
Posted: Fri Jul 17, 2020 11:30 am
by Dave Wolfe
Has anyone done a FFT of the cabin noise to see if there is anything in particular dominating the noise footprint?
Re: cabin noise
Posted: Fri Jul 17, 2020 1:00 pm
by GraemeSmith
peter anson wrote:I have a Flightcom 403MC intercom connected to a Microair radio.
My old MGL and my current Garmin radios - both with combined Intercoms had a setting to adjust for sensitivity of dealing with background noise. Don’t know about yours - but that’s the first place I’d look.
Re: cabin noise
Posted: Fri Jul 17, 2020 3:41 pm
by Johns
Thanks Peter, great link. At least I know what doesn’t work. I have a Lightspeed ANR set of headphones which work great but was thinking the quieter the better. Without the anr it is almost unbearable. Thanks everyone! John
Re: cabin noise
Posted: Fri Jul 17, 2020 5:05 pm
by peter anson
My old MGL and my current Garmin radios - both with combined Intercoms had a setting to adjust for sensitivity of dealing with background noise. Don’t know about yours - but that’s the first place I’d look.
Damn, you’re right. It does too. There’s a trim pot hiding under a punch out foil cover. Thanks!
Peter
Re: cabin noise
Posted: Fri Jul 17, 2020 6:46 pm
by Corby202
I used a heat shield material on the inside of the firewall. Meant for cars, got it off Ebay. This was fitted during the build so I cant give a before and after report on the noise reduction. I also tried sticking thin foam insulation onto the panels behind the seat, no noticeable improvement there. ANR headset works the best with a mic muff. Sometimes the battery runs out while flying, get me every time, sudden jump with the noise increase until I realise what’s just happened.
Re: cabin noise
Posted: Sat Jul 18, 2020 9:44 am
by builderflyer
peter anson wrote:I have Bose A20s and agree that they work well but when I talk on the intercom to a passenger the microphone does a great job of picking up the cabin noise so that I am talking over a roar, which was the reason I was originally trying to reduce cabin noise. I have a Flightcom 403MC intercom connected to a Microair radio. If anyone has any advice on reducing that roar I would love to hear it. I have tried different mics on other headsets but no improvement.
Peter
Peter, you may already have the solution. I’m using the intercom built into the Microair 760 com radio and experience very little background noise when it is turned on. First, did you have someone verify that you don’t have a “roar” on your transmissions as well? Assuming no roar there, then try turning up the sidetone adjustment on the Microair until you’re satisfied with the results using your intercom. That should work for you.
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: cabin noise
Posted: Sat Jul 18, 2020 9:48 am
by Area 51%
On every WW2 show I’ve ever watched that involves pilots and winged bomb carriers, the pilot’s microphone seems to be getting it’s signals from the user’s voice box.
Was that just a handy place to keep the push-to-talk switch, or is there some lost technology we need to revisit for our noisy aircraft?
Re: cabin noise
Posted: Mon Aug 24, 2020 11:12 am
by lpaaruule
I was skeptical that the Bose a20 headset would be that much better than my passive halo headset. However, based on the previous recommendations, I found a set on Ebay for a good price. Wow, you guys were right, the difference is incredible. I like starting the engine, then turning the headset on just to marvel at the difference.
Thanks!
Re: cabin noise
Posted: Tue Aug 25, 2020 9:30 am
by builderflyer
lpaaruule wrote:I was skeptical that the Bose a20 headset would be that much better than my passive halo headset. However, based on the previous recommendations, I found a set on Ebay for a good price. Wow, you guys were right, the difference is incredible. I like starting the engine, then turning the headset on just to marvel at the difference.
Thanks!
Paul, happy to hear that your Bose is doing the job for you. My experience is different from yours in that the Halo in the ear headset works better for noise reduction than either my Lightspeed Zulu or a Bose when I had a chance to compare it with the Lightspeed. However, It is necessary for me to use the smaller ear plugs (not the typical large yellow ones) with the Halo to get a tight seal in the ear canal. Just my observation.
Art,Sonex taildragger #95,Jabiru 3300 #261
Re: cabin noise
Posted: Tue Aug 25, 2020 2:45 pm
by N190YX
Keep in mind that, while the Bose’s active noise reduction (ANR) is as good as any, its passive (without ANR) noise reduction is very poor. I have both Bose and Lightspeed Zulu headsets in my airplane, they are both excellent, but the Bose is essentially useless if the batteries go dead. The Lightspeed and other headsets I have tried in the booths at Oshkosh have good passive noise reduction, but not the Bose.
Re: cabin noise
Posted: Tue Aug 25, 2020 7:16 pm
by Corby202
The best improvement I get with my Headset is after a haircut. The cups seal much better. Its just I prefer to spend money on my plane rather then helping the barbers son go to University.
Re: cabin noise
Posted: Tue Aug 25, 2020 10:42 pm
by radfordc
https://www.homebuiltairplanes.com/foru … 400.33850/
Re: cabin noise
Posted: Thu Aug 27, 2020 11:44 am
by waiexpilot3mj
As far as cabin noise goes I probably have one of the loudest due to my Corvair installation. I use a Zulu3 headset. I have a video on youtube that demonstrates the noise as I hear it without and with the Zulu3 ANL off and turned on. It is located at approximately 6:20 into the video. Check it out at
https://www.youtube.com/watch?v=OxyxXrtEm-Y&t
Mike
Waiex/Cleanex 23
Florida Sonex Association
Re: cabin noise
Posted: Thu Aug 27, 2020 5:28 pm
by stroudj002
I have tried both the Bose A20 & Lightspeed Zulu 3 headsets either one did not provide the sound dampening that I was looking for. I have been using CLARITY ALOFT HEADSETS for 4 years, I have been well pleased with it performance. Does not require batteries fo work. The only negative is that you have to change the earbuds about once a month.
Jim Stroud
Re: cabin noise
Posted: Thu Aug 27, 2020 7:00 pm
by GraemeSmith
Everyone is different. Physical shape of head, beards, sideburns , hair disrupting over ear seals, your remaining hearing range as you age. 'in ear buds and sizes and how good the seals are. Even if you are using in ear hearing aids. One person’s perfect headset is another person’s poison.
This is when you need a good pilot shop with a range of headsets to try. And this is when it is a shame that the online world has put them out of business…