Inc. ANR Upgrade Kit
Sonerai IIL N994SP
After the third flight of my Sonerai IIL, it was apparent that I had a
problem. The engine and wind noise in the cockpit made it difficult to
impossible to hear air-to-air CTAF radio traffic on my David Clark H10-13.4
headset. I needed to find a solution to this problem and one which would
not require much money or modification to the aircraft. An ANR (Active
Noise Reduction) headset was the obvious solution but I just sank a good
chunk of change on the H10-13.4 and I didn't want to spend several hundred
dollars on another headset. I decided instead to upgrade my H10-13.4 to
ANR stature using Headsets Inc.
ANR upgrade kit. Fortunately for me Headsets
Inc. is located in my hometown of Amarillo, Texas. After educating
myself on the Headsets Inc website,
I made the short drive to their office to purchase the upgrade kit and
the optional 9 volt auto-shutoff battery holder.
The Headset Inc
ANR upgrade kit contained all parts necessary for the conversion.
It even included a few inches of solder! A pencil tip soldering
iron, wire cutters and screwdriver were the only tools needed to
successfully perform the upgrade.
first step of the upgrade is to remove the gel ear seals. These simply
slide off the ear cups.
remove the donut shaped foam from the inside of the ear cups. These
foam pieces will not be reused. Removal of the foam will expose the
the screws that anchor the speakers to the ear cups. Lift the speakers
from the cups. Note the colors of the two wires that go to the speakers.
On the H10-13.4, the green wires are the audio (+) and the black are
the audio (-) and common ground.
the wires from the speakers by unscrewing the terminals and pulling
the pins out. The speakers are not used in the ANR upgrade and can
parts removed from the headset. Only the gel ear seals and inner foam
pieces will be reused.
1/4 inch hole must be drilled in the left ear cup for the ANR module
power supply cable. A rubber grommet is supplied in the kit and is
fitted into the hole prior to slipping the cable through. You can
avoid drilling this hole by purchasing the optional $19 AMP cable
from Headsets Inc. This cable
combines the audio/mic cable with the ANR power supply and makes for
a tidy installation. If you're on a budget like I am, a 1/4 inch hole
and a few tie wraps are acceptable.
comes the wiring. First remove the original cross-over audio cable
that runs from the left cup to the right. This is replaced with
a new crossover cable supplied in the kit. Second, splice the common
ground and audio (-) wires inside the left cup. Third, splice the
audio (+) wires. When done, three wires will extend from each cup;
the audio (-), audio (+) and positive power. The installation manual
has a simple to follow wiring diagram.
soldering the three wires to the ANR module, insert the original foam
pieces that were located under the speakers back into the cups. Do
not reuse the original foam donuts. Instead, use the pink temper-foam
supplied in the kit. After the foam is inserted, solder the three
wires to the lugs on the ANR module.
soldering the three wires to each ANR module, insert the modules into
the cups. Double-sided tape supplied with the kit is used to hold
the modules to the cups.
the original gel ear seals onto the cups then insert the felt-like
pads that are supplied in the kit. These pads are necessary to prevent
feedback. I left them off for testing and when the power was turned
on, I was greeted not by the anticipated silence but rather by a deafening
The installation took about two hours to complete
and was not at all difficult. I was anxious to see how my new ANR headset
performed so I took it to the garage, started the lawnmower and turned
on the ANR power. The results were impressive! The sound of the mower
was reduced to a quiet rumble. I can't say scientifically what the noise
reduction was but it was a lot. Interestingly, the ANR dramatically reduced
the mower noise but minimally reduced human voice sounds. I could hear
a person over the noise of the lawnmower better with the ANR turned on
than off. Of course the true test of my new ANR headset will be in the
noisy cockpit on my next flight.