I'm curious how loud a Rans S7S or Highlander are with a Rotax 912ULS. Will a Bose A20 work and make them quiet? I had a real nice PA 12 with a metal interior and it was so loud the A20 popped and couldn't keep up with the vibrating tin. I sold it mainly because of the noise. Thanks for any info.

I don't own an S7 but I do own it's ripoff sister (Savage Cub). The only thing metal inside the plane is the instrument panel and gladly I have never noticed any noise coming from it. All I use is Sigtronics (not noise canceling) headset and it has no trouble making the noise level quite comfortable and communications very easy with both ground or with the GIB. I did go sans headset once when I took up a friend that couldn't find his headset so we both had to go without so we could converse (yell) to each other. I'll never do that again as the noise was quite annoying to me but it was just "normal" noise. I am very sensitive to loud noise as I have blown my hearing working on industrial gas compressors all my life. I never want to hear loud noises again. Consequently I have purchased my own second headset for passengers so I never have to do that again. The Rotax in a Rans or any other fabric plane should never be loud enough that a low end headset couldn't handle it; a better headset would handle it even better. Can't say what would happen in an all metal plane.

The 912 is about as quiet as it gets for an aircraft engine. (besides diesel).

About the same as my T-Craft was. ,

I have an s7/912 ULS and find it very noisy, painfully noisy when I bought it. I had Zulu II's and it overwhelmed them. They would work better off than on. Very hard to hear communications on the radio. It didn't have any insulation on the firewall, so I put a layer of 1/2 " foam on and that helped. I switched to the halo type headset and that helped too, made it bearable. I have now switched to the Bose A20 and it is pretty good now. It's kind of strange. I have talked to some and they say they barely need headsets. I have some carbon fiber components and I hear CF can transmit a lot of noise. I did a 6' exhaust extension and that didn't make any difference. I put a stock exhaust system on it and that helped some over what it came with. Sure would like to get it quieter. People on the ground say it is very quiet going by. I have wondered if any of the noise is coming from the prop. It is quite a bit quieter when it gets down around 4500 rpm.
I guess not much of an answer for ya, just my experience.

shortfielder wrote:I have an s7/912 ULS and find it very noisy, painfully noisy when I bought it. I had Zulu II's and it overwhelmed them. They would work better off than on. Very hard to hear communications on the radio. It didn't have any insulation on the firewall, so I put a layer of 1/2 " foam on and that helped. I switched to the halo type headset and that helped too, made it bearable. I have now switched to the Bose A20 and it is pretty good now. It's kind of strange. I have talked to some and they say they barely need headsets. I have some carbon fiber components and I hear CF can transmit a lot of noise. I did a 6' exhaust extension and that didn't make any difference. I put a stock exhaust system on it and that helped some over what it came with. Sure would like to get it quieter. People on the ground say it is very quiet going by. I have wondered if any of the noise is coming from the prop. It is quite a bit quieter when it gets down around 4500 rpm.
I guess not much of an answer for ya, just my experience.

I agree, my S7S is pretty loud. Also use the Zulu II. While the headset does a good job of attenuating the low frequencies, the Rotax runs at a high RPM and the active attenuation at that frequency is not that effective. I've talked to many headset providers and they all said it is hard to make an active system tuned to the higher RPM's. Maybe in the future. I run mine at 4600-4800 where is is quieter but still see 90-95 MPH.
Pete

I have used my LS Zulu's and my Quiet Technologies in-ear headsets. Both have worked sufficiently but then I will mention that I have hearing lose and hearing aids. Take out the hearing aids and using either type works good.

As mentioned in a previous post, people I fly over mention the plane is very quiet.

If it's to loud, put the Swiss muffler on it like courierguy had on his S7.

I will say my 912 Merlin is quieter than a 150 Cessna and my Polaris ranger with a cab.

No problem with ANR helmet and headset in our S7S. They are both the same brand...the headset is one of those upgrade kits in a David Clark.

Now the water infiltration is a different matter. Back seater needs a snorkel.

shortfielder wrote:I have an s7/912 ULS and find it very noisy, painfully noisy when I bought it. I had Zulu II's and it overwhelmed them. They would work better off than on. Very hard to hear communications on the radio. It didn't have any insulation on the firewall, so I put a layer of 1/2 " foam on and that helped. I switched to the halo type headset and that helped too, made it bearable. I have now switched to the Bose A20 and it is pretty good now. It's kind of strange. I have talked to some and they say they barely need headsets. I have some carbon fiber components and I hear CF can transmit a lot of noise. I did a 6' exhaust extension and that didn't make any difference. I put a stock exhaust system on it and that helped some over what it came with. Sure would like to get it quieter. People on the ground say it is very quiet going by. I have wondered if any of the noise is coming from the prop. It is quite a bit quieter when it gets down around 4500 rpm.
I guess not much of an answer for ya, just my experience.

Absolutely, the type of prop can make a huge difference. My Prince P-Tip (78") had a a nice real deep tone to it. I also mostly fly at 4800 to 5000 RPM. My Zulu 3 headset works so well, that when I first got it I called a buddy in AZ on my 'droid phone, and we talked for 10 minutes before I told him I was in the air, and he was astounded. My earlier Telex ANR's were OK, but no where near as effective as the Zulu's.