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-   -   Question for Bonehead helmet users (https://vansairforce.net/community/showthread.php?t=190542)

Malndi 12-29-2020 04:46 PM

Question for Bonehead helmet users
 
We recently bought four Pilot-X helmets with CEP and after dialling them in were really happy, with one exception- background noise is dominating our intercom and transmitted audio to the extent that were virtually unreadable to each other and everyone else on the same frequency.

We all use different radios (A210, SL40, G430, GTR200) and weve each played with our mic gain and other settings. Weve also swapped helmets and planes, all to no avail. Were now trying to determine if/why the mics are the problem.

Our helmets came with Pilot PA-7X microphones. Itd sure help to hear from anyone else with a Pilot-X helmet about the type of mic fitted to their helmet and whether they have encountered a similar issue?

Thanks

fl-mike 12-29-2020 06:27 PM

I helped a buddy with another gee-wiz brand helmet, and I don't know why they use crappy mics in them (in my opinion). I threw on an old David Clark M-7A I had and it solved the problem (ANR feedback).

Kahuna 12-30-2020 08:35 AM

I have a bonehead I use in my Pitts. Never used in my RV (use a Gibson in my RV) and I only break squelch in certain maneuvers. Its a single hole so I dont care really. The Pitts is waaaaay louder in the cockpit than the RV. My bonehead has a mic foam muff. If I was bothered by it, I would try the leather mic muff before I did anything else. Available from many suppliers.

jbDC9 12-30-2020 09:26 AM

Quote:

Originally Posted by fl-mike (Post 1489701)
I threw on an old David Clark M-7A I had and it solved the problem (ANR feedback).

This right here.

I fly some noisy stuff, so awhile back I tried that Pilot PA-7X “high noise” mic on one of my headsets. Meh, unimpressed. But, on my HGU-55 helmet I have the David Clark M-7A mic; works great even in the noisy AT-6 or stupid loud T-28D. Gotta have the mike muff to go with it though...

Malndi 12-31-2020 10:36 PM

Thanks for the suggestions.

I took the M7A mic from a spare DC headset and tried it in the helmet. There was a small improvement in sound quality, but my wingman said the background noise was still there, so Ill try again with the addition of a leather mic muff.

But its interesting that the same M7A mic doesnt suffer from background noise when used in the headset. Im now wondering if the helmet is conducting noise and transferring it via the mic boom? I think this warrants more investigation.

Gash 01-01-2021 12:35 AM

I've been flying a Bonehead helmet in the Extra. Like Kahuna, I put that Oregon Aero mic cover on, but it still picks up a ton of background noise in my radio transmissions. Sometimes I have to hold my hand over the mic to reduce the noise. To answer your question, I really don't think it's being caused by conducted vibration. It's just good old 105 dB cockpit noise.

I just got sponsored by Lift Aviation and am getting one of their helmets to use in the Yak 50. This helmet will have the brand new Tiger Performance ANR headphones and mic (it's not advertised on Lift's website yet). I'm hoping for an improvement in transmission quality. I'll post a review here after I get a chance to put it through the wringer.

MK77 01-06-2021 12:58 PM

Very interesting. I used the super basic Bonehead helmet when I was conducting the phase 1 for my RV-7. Not sure what kind of mic capsule was in it. At that time I had no carpet, Vetterman 4-pipe exhaust and it was pretty loud in the cockpit (>100 dB-A SPL). Radio is a GTR200. Had no issues with breaking squelch on that mic as I recall.

Now I use a Sennheiser S1 and the mic performance is noticeably worse than others I used. A lot more background noise is picked up when I speak but it still doesn't generally break squelch unless I 'm speaking. A bit funny since I expected the Sennheiser to have better performance since they're known for their microphones.

I actually design microphones for a living. The type of mic, polar and frequency response will make a big difference in the amount of background noise it picks up. Most mic's for this application are what are referred to as "noise cancelling" which is a bit of a misnomer. More accurately they should be called "noise rejecting". Not sure what the specs of the mic in question are.

I'd be surprised if the mic 'muff' makes a big difference, at least not without impacting the quality of the speech pickup as well.

rmarshall234 01-06-2021 07:40 PM

This in an interesting thread.

I will soon be adapting a Bonehead Mamba skydiving helmet for use in the biplane I am building. The Mamba has a CF chin guard which I like, and I will mount the mic inside that chin guard recessed area. The ambient noise in this BP should be pretty high, it will be interesting to see if I incur the same noise issues as mentioned here. It might be several months before I'm up and running, but I'll report back if I have positive results.

MK77 01-07-2021 10:02 AM

Let me know when you are getting ready to mock up your helmet with the mic. I'm sure I can give you some pointers for maintaining the performance of the mic element with your mounting scheme.

rmarshall234 01-07-2021 10:43 AM

Awesome, will do, thanks so much!


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