In 1997, LightSPEED Aviation stood the aviation headset market on its ear when the company introduced an under-$500 ANR unit comparable in quiet and comfort to Bose’s kilobuck model. Now, they’ve done it again. AVweb editor-in-chief Mike Busch just flew across the country with LightSPEED’s new $150 QFR "Solo" passive headset, and reports that it’s the quietest and lightest passive ever. As if that wasn’t enough, the company plans to introduce an even quieter ANR version next month, priced at (are you ready?) less than $280. You’ll find all the gory details and photos in Mike’s review.
October 2, 2000
LightSPEED just introduced a what?
Did you say a passive headset?
In the year 2000? Are they nuts?
Well, yes, LightSPEED's latest headset is indeed passive. And no, they're
not nuts. In fact, after having just flown my Cessna T310R across the country
while wearing the new LightSPEED QFR "Solo" passive headset, I think this may
be the smartest thing they could have done. Read on and I'll tell you why.
I remember when I first discovered the LightSPEED 20K ANR headset. It
was June, 1997, and nobody in aviation had ever heard of this little company
in Oregon. But the moment I put the 20K on my head, I knew they'd hit a home
run. Here was an ANR headset that cost less than half the price of the
industry-standard Bose Series II, yet was every bit as quiet as the Bose, and
every bit as comfortable. (In fact, I found it more comfortable than the Bose,
although comfort is extremely subjective.)
Granted the microphone didn't sound quite as good as a Bose or David Clark,
and it chirped a bit near ATC radar antenna sites, and it needed a new set of
AA batteries with some regularity. But all in all it was a lovely headset, and
nothing else even remotely in the same price range could touch it. I wrote a
glowing review of the 20K, as did Aviation Consumer, and the 20K went on to
become a smash success.
In 1999, after several other firms introduced under-$500 ANR headsets to
compete with the 20K, LightSPEED introduced the 20XL and 25XL. These were
evolutionary, not revolutionary. The 20XL was basically a 20K with
much-improved battery life and a clever automatic shutoff feature that neatly
solved the problem of forgetting to turn off the ANR after landing, and then
finding the batteries dead at the beginning of the next flight. Both were nice
enhancements, and the 20XL is a terrific headset.
In its top-of-the-line 25XL (priced at just under $600), LightSPEED's
objective was to create the quietest ANR headset in history. They did, but
after flying with it for several months in the fall of 1999, I concluded that
I wasn't quite as happy with the 25XL as I was the 20K and 20XL. The 25XL
headset was slightly better than the 20XL in attenuating low-frequency noise,
but it also struck me as being a bit unstable at times. I found that actions
such as moving my head or jaws or adjusting my sunglasses would sometimes
trigger funny growling or groaning sounds from the headset. Once, I even found
a female controller whose voice seemed to drive the thing crazy. In adding
sophisticated circuitry to crank up the 25XL's ANR gain to the highest stable
value possible, it seemed to me that the headset was operating so close to the
edge of the stability envelope that it occasionally crossed the line into
As LightSPEED's own excellent series of technical articles (ANR 101 — A Tutorial on
Active Noise Reduction) points out quite clearly, the amount of active
noise reduction that one can achieve is limited by the fact that the more ANR
you try to achieve, the more acoustic instability you create. Turning up the
ANR gain too much can result in oscillation, and it struck me that the 25XL
was right on the hairy edge of instability. After a few months of flying with
the 25XL, I decided this was just too much of a good thing, and returned to
using the 20XL for my day-to-day flying.
(Again, this stuff can be very subjective, and there are lots of pilots who
just love the 25XL. LightSPEED's Allan Schrader tells me that the company made
some tweaks to the 25XL ANR cancellation profile in recent months to improve
stability, and suggested that I give the 25XL another try. I'll probably do
In its XL-series, LightSPEED appears to have taken active noise reduction
to its practical limit (and perhaps briefly beyond). But this technology is
capable of addressing only low-frequency noise. No matter how superbly ANR is
engineered, it can't do much about noise in the middle- and high-frequency
spectrum. To deal with noise above about 250 Hz, one must turn to some other
technology than ANR. And that's precisely the direction LightSPEED seems to be
moving in launching their new QFR product line.
I flew with the new LightSPEED QFR Solo on a 20-hour
cross-country trip from California to Alabama and back, with a bunch of stops.
The QFR is a significant achievement. The Solo is a purely passive headset,
but it's the quietest, lightest, most comfortable passive I've ever worn. And
I've worn a bunch.
For a decade, I flew with David Clark's top-of-the-line H10-80 headset,
which was the quietest headset of its day. It cost $300 (in 1987!), weighed
something like 24 ounces, and had a noise reduction rating (NRR) of 24
decibels. The "green monster" was uncomfortable as hell — after a couple of
hours, it felt like a cross between a bench vise and a blacksmith's anvil —
but it did block most of the noise.
When David Clark came out with its lightweight H10-13.4 headset — so named
because it weighed only 13.4 ounces, only slightly more than half as much as
my H10-80 — I snapped one up immediately (for about $200). The H10-13.4
claimed a NRR of 21, just 3 db less than the H10-80, and I figured that was a
reasonable tradeoff for the lighter weight. Boy, was I ever wrong! The first
time I applied takeoff power while wearing the H10-13.4, I almost aborted the
takeoff because the noise level was so high that I figured I must have left
the cabin door open! After a few more flights, I demoted the H10-13.4 to
passenger headset status and never wore it again. A lot of folks must have
reacted the same way, because David Clark subsequently changed from foam to
gel-filled earseals on the H10-13.4, raising its NRR to 23 and its weight to
15 ounces (although the "13.4" model number remained).
LightSPEED's new QFR Solo is significantly lighter (11.8 ounces)
and much quieter. Its NRR is a truly astonishing 28.7, far better than any
other passive headset on the market. Its NRR is nearly 3 db better than the
closest NRR-rated competitor, Peltor's 7005/7006; nearly 5 db better than my
old green monster David Clark H10-80 (which weighed more than twice as much);
and 6 to 8 db better than the DC's "lightweight" H10-13.4 (depending on
whether it has foam or gel-filled earseals).
Incidentally, be very careful in comparing the noise-reduction claims of
various headset manufacturers. NRR provides a specific method for testing a
headset's noise attenuation over a wide frequency spectrum, weighting the
various frequencies, and arriving at an overall rating in decibels. For
manufacturers who publish NRR ratings for their headsets (such as David Clark,
LightSPEED, Peltor, Sennheiser, and Telex), those ratings can be compared
meaningfully (and LightSPEED's QFR Solo is clearly at the top of the heap at
the moment). However, some manufacturers do not publish NRR ratings, notably
Flightcom, Pilot Avionics, and lots of "private label" headsets (most of which
are actually manufactured by Pilot Avionics but sold under other brand names).
Sometimes, the marketing claims for these headsets often cite noise reduction
figures (generally obtained at one specific optimum audio frequency) that are
greatly in excess of what the NRR would have been for that headset. (Some
claim 24 to 26 db attenuation, but if their NRR was published, it would
probably be around 20.) So never try to compare noise reduction figures unless
they're specifically given as "NRR."
Microphone and boom.
My subjective reaction while flying with the QFR Solo bears out these
numbers. I found it much, much quieter than the H10-13.4, and also more
comfortable to wear. In fact, during cruise flight, I found the QFR Solo to be
very nearly as quiet (subjectively) as my LightSPEED 20XL ANR headset. The
only time I really noticed the difference in noise reduction (and wished I
could switch on some ANR) was during takeoff, and to a lesser extent during
climb, when ANR's superior attenuation of high-intensity, low-frequency engine
and prop noise is most apparent. But as I leveled off and came back to cruise
power, the low-frequency engine and prop noise became less and the
high-frequency wind noise became greater, and that's where a good passive
headset really shines ... and the QFR Solo certainly did.
During cruise, I tried repeatedly swapping headsets with my co-pilot —
changing from the QFR Solo to the 20XL ANR and back — and there really wasn't
a clear winner. The 20XL reduces engine noise a bit better, but the QFR Solo
reduces wind noise better. The 20XL's deep, ultra-soft thermosensitive foam
earseals are a bit more comfortable, but the QFR Solo weighs less and has a
better microphone and mic boom (more on this shortly). The bottom line is that
while I clearly prefer an ANR headset for takeoff and climb, at cruise (which
represents the vast majority of noise exposure time) I found the new QFR Solo
passive to be very nearly as good, and in some ways better.
Comfort is even more subjective than quiet. I found the QFR Solo to be very
nearly as comfortable as the 20XL. My co-pilot did not. Upon further probing,
my co-pilot's problem turned out to be an uncomfortable "pressure point" where
the earpieces of his sunglasses passed beneath the earseals of the headset. I
was also wearing sunglasses of similar design (wire frames with plastic-tipped
earpieces), but I felt no such discomfort. Obviously, either our glasses were
slightly different, our head shapes and skull structures were slightly
different, or both. Whatever the exact difference, this underscores my
often-repeated advice that no matter how many specs and review articles you
read, there's no substitute for actually evaluating a headset in the aircraft.
Most reputable dealers offer a 30-day return privilege, giving you an
opportunity to try the thing in flight, and I suggest not purchasing from any
dealer who doesn't.
The QFR Solo bears very little physical resemblance to previous offerings
from LightSPEED. The distinctive triangular earcups that have become the
signature of LightSPEED's ANR headsets are gone, replaced by big rectangular
earcups that look a lot heavier than they actually are. No volume-control
knobs protrude from the earcups — to save on-the-head weight, LightSPEED has
placed the volume controls and stereo/mono switch in a small remotely-mounted
control box near the plug end of the cord. The earseals are soft foam, quite
comfortable but not nearly as deep as the pillowy soft ones LightSPEED uses on
its K- and XL-series.
The headband is very thin compared to previous LightSPEEDs. It does have
padding, but not a lot. Nevertheless, I found it quite comfortable, as did my
co-pilot. When a headset is this light, a thickly-padded headband is
apparently not necessary. A bonus is that the thin headband provides
much-improved cabin headroom.
The headband is attached to the earcups via adjustable piano-wire yokes
very reminiscent of the Peltor 7000-series. These yokes look less substantial
than the plastic ones used on previous LightSPEEDs, but the system has proven
quite rugged in Peltors and I see no reason why it shouldn't do as well
I've always considered the weakest feature of the K- and XL-series headsets
to be their microphones. I've found LightSPEED's gooseneck mic boom to be too
thin and flexible, making it easy for the mic to creep or be bumped out of
proper position. I also didn't particularly care for the frequency response of
the LightSPEED microphones, feeling that they were weak at low frequencies and
too sensitive at high frequencies, resulting in somewhat tinny-sounding speech
and too much wind noise in the background. Also, the microphone output level
was lower than other headsets, sometimes causing undermodulation and
I was therefore delighted to see that LightSPEED addressed all these issues
in the new QFR. The mic boom is still the gooseneck type, but it's shorter,
thicker and noticeably stiffer, and once adjusted stays firmly in position.
The mic itself has a much better tonal quality, with better bass response and
less wind-noise pickup. It even has little pointy "muff grabbers" to ensure
that the foam mic muff cannot slip off accidentally. Finally, the new mic has
a microphone level adjustment so that it can be tweaked for best compatibility
with the aircraft radios and intercom. (In my case, however, the output level
seemed just fine right out of the box, so I didn't mess with the level
I'm told that LightSPEED is considering this new microphone and mic boom
for its higher-priced XL-series, too. I'd certainly encourage them to do this,
and would consider it a very welcome improvement.
In a month or two, LightSPEED has scheduled the introduction of an ANR
version of this headset, dubbed the QFR "CrossCountry." Their idea is to take
what is already an absolutely superb passive headset and add some "mild"
active noise reduction to improve noise attenuation in the critical
low-frequency spectrum below 250 Hz where all passive headsets are at their
weakest. This ANR version should weigh less than 14 ounces.
The QFR "CrossCountry" is expected to sell for under $280 — half the price
LightSPEED's top-of-the-line 25XL. Look at it this way: For the price of one
Bose Headset X, you'll be able to buy CrossCountry ANR headsets for both pilot
and co-pilot plus Solo passive headsets for two passengers, and have more than
$100 left over! That's pretty compelling.
I can't wait to get my hands on this headset. Based on what I've seen so
far with the QFR Solo, I expect the QFR CrossCountry to be
There are a number of reasons why you might want to consider this
- You're a price-conscious buyer looking for the "best anti-bang for the
buck." At under $150, the QFR Solo is around one-third the cost of a good
ANR headset like the LightSPEED 20XL or similar headsets from Denali,
Peltor, Sennheiser, Telex, etc. Yet the comfort and performance are quite
adequate, especially in cruise.
- You're flying an aircraft with less low-frequency noise and more
mid-range noise than average. Examples include the Rotax-powered Katanas,
some helicopters, and lots of experimentals ... not to mention turbine
aircraft. At noise frequencies above 250 Hz, you just can't beat a good
- You prefer a headset with less weight and less bulk. My wife, for
example, simply refuses to wear "one of those big and clumsy things" (as she
calls my LightSPEED XL20s) and opts instead for foam earplugs, cutting her
off from the aircraft intercom. The QFR is a more attractive option for such
To be sure, the new QFR-series is meant to provide a lower-cost alternative
to the XL-series, not replace it. The high-end ANR design of the
XL-series still offers some distinct benefits: deeper, softer "confor-foam"
earseals, improved speech intelligibility, extended battery life and automatic
shutoff, just to name a few. So I don't expect to be giving up my 20XL headset
But with the introduction of the under-$150 QFR Solo and the soon-to-come
under-$280 QFR CrossCountry ANR, LightSPEED has once again redefined the
price-performance targets for low-price aviation headsets. As occurred in
1997, other manufacturers will undoubtedly follow LightSPEED's lead and
introduce competitive headsets. This can only be good news for pilots and
Nice work, LightSPEED!
LightSPEED has a web site where you can
review the features and specifications of LightSPEED XL and QFR models, read
answers to frequently-asked questions, learn a great deal about the theory and
design of ANR headsets in general (and LightSPEED's in particular), and order the headsets online.
LightSPEED headsets are also available from various authorized dealers
(including several who are AVweb sponsors). Some of these dealers offer
the headsets at small discounts from list. There's not a lot of dealer margin
on these units, however, so don't expect big discounts.