cabin noise

[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

[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

[GraemeSmith]

Bose A20's - but on your ears - not on the firewall. :-) Said with a smile.

YMMV

[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.

[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

[Dave Wolfe]

Has anyone done a FFT of the cabin noise to see if there is anything in particular dominating the noise footprint?

[GraemeSmith]

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.

[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

[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

[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.