All comments given with the understanding that each person is different and
has different preferences.

Denny wrote:
: Hmmm, interesting Cory... I settled on the 20-3G's for Fat Alberts
: seats... Now, I have exactly the opposite experience, in that when I
: turn OFF the ANR I the radio volume is overwhelmed by the engine noise
: and have to turn it up to a loud level... When I turn the ANR back ON
: suddenly the radio is blasting my ears.. The radio has no way of
: knowing or responding to the ANR setting of the head set... This
: behavior is identical to every ANR headset I have used... You can
: check to see if there is a difference in the audio passed throught he
: headset by listening to the radio with the engine off and switching the
: ANR on and off...

Couple of issues with this. First of all, the active part of the headset can
be set to amplify the incoming signal when activated. Secondly, the incoming signal
could be frequency shaped... either directly, or through the feedback path of the ANR.
Thirdly, the "loudness" is a *perceived* amount... frequency-dependent and
invidual-person independent.

I personally find on the 20-3G-flavor Lightspeeds that without the ANR, I
cannot hear much of anything out the radio or intercom without having it up painfully
loud. With the ANR on, the engine magically disappears, but I *still* cannot
adequately understand the speech over the radio or intercom without having the volume
up too loud. I suspect it has to do with the amplification of the noise in the voice
range (1-2kHz) as in my original post.

... and yes, I've had my hearing checked recently. I helped a fellow grad
student a year or so ago here at Tech who needed certificated IFR-rated pilots for a
BUNCH of sim time. Part of that was a thorough hearing test. If anything, I might be
overly sensitive due to good hearing

: I fly in a friends planes (GlassAir and P-Centurion) and he is a Bose
: True Believer. with 8 sets of them.. I am not impressed with his
: headsets... They sound good in his P-210, which is cathedral quiet to
: start with, in fact so good I normally push them up on my hat because I
: can hear just fine without them... In the GlassAir they lack passive
: reduction for that rip snorting engine out front and the scream of air
: going over the airframe at 230 knots...

Passive: Good at "high" frequencies... where "high" is more or less determined by the
relationship between the frequency and the mass of the headsets. That's why putting
your hands on a passive headset helps dramatically with engine noise.... hands ==
more effective mass. Unfortunately, headsets have to be light for fatigue reasons.

Active: Good at "low" frequencies... Engine and it's first harmonics relatively easy
to cancel. Unfortunately, too agressive of performance within a low-frequency band
often leads to "spill-over" at high frequencies.

: On long flights, I have never found a headset that gets better as the
: hours go by... This past summer I made numerous trips hauling
: grandchildren around the Great Lakes.. 6 to 9 flying hours a day at a
: time... From experience I know how the headsets aggravate after a few
: hours.. I took DC's, and LightSpeed, and Telex sets with me and swapped
: them as I went along... I was sick of headsets, and airplanes, and
: sitting, and noise, and not being able to pee, by the time I painfully
: crawled back out of the plane... It did NOT get better as the day wore
: on... The LightSpeed is the best of the bunch in my opinion, ymmv..

Another reason I like the Lightspeed QFR-CC headsets. Minimal clamping force
makes the pretty comfortable. Mild ANR takes the edge off the engine.

As an interesting side-note, I've got a friend with a Sea-Ray... experimental
2-place flying boat (fiberglass hull, high-wing, pusher, with Rotax 912S mounted high
and behind the cockpit). It's gear-reduced, so engine RPM is typically around 4500 in
cruise IIRC with a 3-blade prop. Using his Lightspeed 25XL's (or similar), I
literally couldn't tell if the headsets were on or not in flight... higher frequency
engine noise not cancelled, and the passive performance was minimal where it counted.
I could converse with him easier with the headset off my head.

He tried my QFR-CC headsets and the next day bought 2 of them for the plane...

Oh... and almost this exact topic was the subject of my dissertation which I
finished this past spring...

-Cory

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************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
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