Side Tone and Bose A20 Headsets

[Runtoeat]

Is there anyone using Bose A20 headsets that seems to have a lot of cabin noise during transmit? Seems like there's a lot of cabin noise in the background, especially when I have the window vents open which adds a lot of ambient cabin noise. I've tried "000" up to "030" side tone settings on my Garmin SL40. Going up from "000" seems to increase the side tone noise somewhat but doesn't seem to make much difference. Any thoughts or comments would be welcome.

[Al Downs]

I just got my Zulu headset back from the factory. I had some of those same things but also had some squealing. They repaired it for me at no charge.

[FredG]

Dick, I fly my CTsw with a Bose A20 headset. I do not have a lot of cabin noise in the background during transmit. My comparison is a set of passive Dave Clarks and a Telex Stratus D50 ANR. I have to look at the manual, but do the Bose have an internal way to change microphone gain (i.e., an adjustment to the headset or headset control box, not the intercom or radio)?

[Gmoore7]

I use Telex Stratus D50 ANR. When I purchased my CTsw the previous owner said I should get Telex as the plane noise is rather loud and he found these to be the best.

I really can't compare with any authority, but I do not have any trouble hearing with the telex.

[Roger Lee]

Hi Dick,

 

Make sure your mic is turned toward your mouth and not the other way. It shouldn't have a lot of noise at all.

[Jim Meade]

Dick,

A local pilot with a Dynamik complained of the same problem as you have, but the cabin layout is quite different.

 

When you say window vents open, do you mean the little pop-out scoop vent or is the entire window slid back? That may make a difference.

 

Do you have a muff on your microphone? Have you tried transmitting by cupping your hand around it to block any moving air to see if that changes things?

[N751JM]

Dick,

 

I fly with the Bose A20 in a CTLS. When we picked up the plane we had a horrible noise while transmitting, it was simply unusable. It turns out that it was a side tone setting on the Garmin SL40. I'm not in front of the manual (or the airplane) but as I recall there is an "auto" setting (vs specifiying a specific sidetone level) and that is what we needed to set it to. Since that time, no problem. Although I've had to set that in the SL40 of some other deliveries.

 

It may or may not be the problem, but I know if all is working well the Bose A20 should work fine with the CTLS.

[Runtoeat]

Fred G. - good idea to compare A20 with a different h'set. I also fly with one Bose and one David Clark and didn't think about comparing these but will do this. Roger, I think I've checked the orientation of the mic but it pays to check this again. Jim - yes, the small vents. These really do add quite a lot of noise to the cabin. Some time ago, I determined that the cabin was noisier with the carb heat pulled out when using my DC h'set. I do have the muff on the mic but I like your idea to cup my hand around my mouth. Will try that. N751JM - I believe the "auto" side tone setting you refer to for the SL40 is the "000" setting which slaves the side tone to the transmit levels of the mic. This "000" setting is the same for the SL30 which is the radio I have. This setting seems to work for others and it is probably a good setting for the A20. I am really not sure if I'm getting an unusual amount of cabin noise during transmit. I am suspecting that the background cabin noise is also being heard by those receiving my transmission. One simple thing I will also do is to ask my friend if he hears me OK or if my voice is masked by cabin noise when we're both up cruising WOT in our CT's. Thanks for the replies. This helps sort things out.