Scroll past the rave "review" at the top of
Bose A20 review. Another leap in ANR. | The Joy of Aviation
to the comments section: "Erin" and "Bob" found their A20s to squeal,
and "Fred" shows how to reproduce that:
You do not even need to be in the cockpit to reproduce the problem. You just need to put the ANR on (yes this is an ANR issue). Then you put the headset on your head and you press the ear cups towards your head (after a while in flight the seals are always a little bit compressed). Then you remove the ear cups at different speeds. Try this a few times and you will hear the squeak/squeal sound for sure! In flight this happens naturally when the headset is moving a bit when you touch at the mike or move your head rapidly for instance. Conclusion: All Bose A20 have a serious ANR design problem!
I did appr. 10h helicopter training using A20s - hence not qualified to judge - but found that only seriously catching the cord somewhere makes the ANR go crazy, read fail.
Anyone else got that "A20 squeal" and grinding his/her teeth for having to live with that?
Can someone please repeat "Fred's test" with a Zulu2, preferrably side be side with some A20s?
I'm a little bit worried, as I was on the brink of shelling out a grand for an A20..
