Hallo everybody,
I performed a quick test and comparison to measure the noise cancelling of the following headsets:
- Bose A20
- Bose QC35 (not an aviation headset but often used with boom mics)
- David Clark 10-13.4
The setup was the following: I played the recording of a Cessna C172 (found online) with professional loudspeakers (at their 0 dB). At the same time, I put a DPA microphone close to my ear as pictured in the photo .
I measured the sound of the C172 using the DPA with all headphones and these are the results:
No headset ------------> 0 dB
DC 10-13.4 ------------> -13 dB
QC35 no ANC ------------> -6 dB
QC35 ANC ------------> -24 dB
A20 no ANC ------------> -7 dB
A20 ANC ------------> -28 dB
So, the A20 is the winner but just by a little margin compared to the QC35. When ANC is turned off, DC is still a better performer.
I then analysed a bit the type of sound that passes after noise cancelling and as you can see from the picture below, with both Bose with ANC the low frequencies are smoothed a lot. The A20 has a different profile compared to the QC35, with more loss in the mid range. I wonder if this is by design to cope better with specific noise coming from airplanes (while QC35 has a more "general" profile).
As a personal remark, I felt much more comfortable (noise-wise) with the A20.
I can send you the audio recording if you want.
Hope it helps.
Carmine