In rec.aviation.owning Sydney Hoeltzli wrote:
: wrote:
: I'm not really excited about buying any of the 15/20/25/30 K,XL,G
: series because they seems pretty flimsy, have extraordinarily lousy
: passive attenuation (read: LOUD out of active cancellation above 300 Hz),
: and artificually boost the radio's voice frequencies to an uncomfortable
: level. I'm sure the boosting is for "clarify" of old ears that are
: already fried from 40 years of naked flying, but I'm trying to keep mine
: good.

: Cory,

: I'm afraid I don't follow your critique of the K/XL/G series.
: The radio's voice frequencies can be adjusted to any level you
: like with the volume control. I have very good ears and the
: level is not uncomfortable, in fact it is too low on the
: minimum volume setting in our plane. If something was uncomfortable,
: and turning down the volume on the headsets didn't fix it, then
: perhaps the radio volume was turned up too high? We are able
: to combine most headsets in our plane and find suitable settings
: of intercom/radio/headset volume, but it does take a little
: tweaking when a new headset comes into the mix. I'm a little
: puzzled because surely you must have tried this.

What I meant was that it has an active filter in the mix that
boosts the voice frequencies from the radio/intercom. That range
(1kHz-3kHz or so) is what makes speech inteligible, and so they boosted it
to make the radios sound "clearer" and "easier to hear." For me, this
yields a harsher sound in those voice than a plain headset. I don't find
it necessary to artificially boost those frequencies for the radio to be
heard over the intercom. The level on the batt box simply adjusts the
gain, but doesn't adjust these boosted frequencies. While a bit
confusing, that's what I meant. It's not just a level thing.


: You're correct about the poorer Lightspeed passive attenuation.
: It's a direct function of the attraction for Lightspeed owners,
: the comfort. As you probably know, good passive attenuation in
: muff-style headsets is a function of ear seal, and ear seal is
: a function to some degree of clamping force.

Sure. That's why they're touted as very comforable (which they
are). Most GA planes are fairly well sound insulated at the frequencies
that are easy to insulate (1kHz). My plane with minimal internal sound
damping has lots of rattle inside, which makes it unusually noisy in the
1kHz-5kHz range... again the same frequencies that the LS-15/20/25/30
boosts. In fact, I saw a review that showed appreciable spill-over from
the LS headsets in that range. It's a side-effect of attenuating the
100Hz-300Hz range that it actually *boosts* the noise in the 1kHz range or
so. Not pleasant at full-power climbout.

: I don't find the K/XL/G series flimsy except at the poorly-
: designed plug/battery box configuration.

The telescoping action of each side has broken on two separate
friends' headsets. One 25XL, the other 15K.

However, if you do,
: I believe you would find the same to be true of the QFR series.
: My previous headset was a Flightcom Eclipse, regarded by many
: as flimsy, and it served me well so I think there's an issue
: of how gentle one is on equipment.

The battery box doesn't bother me all that much. In fact, I like
the XC-2 and 30G ability to plumb music right in to the headset. If it
truely is 28 dB passive without a vice-grip, then the 10 dB of active it
provides will help cut down the engine even a bit more.

: If you want good passive attenuation and sturdiness, perhaps
: you would prefer a set of Dave Clamps?

Kinda like buying a Sony VCR. It's still built by the lowest
Korean/Japanese/Philpines/Chinese bidder, but stick a name on it and
charge 2x the price. It's rather ridiculous that aviation headsets cost
so much. Even if DC or Bose is slightly better, it certainly isn't worth
the shameless gouging in price.

FWIW
-Cory


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