Bose, Mach1 and ANR
PlankBlender:
I am currently constructing an ANR system for use with various headsets. I have a set of Bose Xs with both a/c and battery power as well as a couple of standard passive types. Once the prototype is done on the passives I want to get a Mach1 set and do the same.
The Bose ANR is interesting...it is a well designed system, however...in typically Bose fashion, the processing is VERY strong. It actually removes a certain amount of sonic information from the low midrange to the high midrange. In the audio world, this is called 'hyping' - the addition of bottom end and the top end to give the system the impression of good sound. The principle is based on the Fletcher-Munsen curve, originally intended to be applied when listening to low level full range sound-to compensate for the ear's lower sensitivity at the extremes of the audible spectrum at low level.
This can make the iPod sound great in certain environments: read in the cockpit.
It doesn't do much to enhance intelligibility of speech...
The MAJOR downside with the Bose is that it attenuates the SPEECH range of the audio spectrum (not so good for listening to ATC). This is IMO due to the fact that Bose like to show amazing specs; ie on paper the NR numbers are great. I practice it is a marketing ploy.
It is possible to retrofit ANR to M1s, which conceptually I like. The thing one shouldn't expect an ANR system to do is remove all external noise. The Bose tries to do that a little too much.
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