Step-by-Step Instructions

for David Clark 'Style' Headsets

Figure 01


Preparing for Installation

      Remove ear seals from each ear cup and place them out of the way to avoid burning them with a hot soldering iron. The earseals stretch around the ear cup flange and are easy to remove. Retain for later use or discard if you will be replacing them.

NOTE: It is mandatory that you use silicone gel type earsels. If your headset has original foam or liquid filled earseals, these will not provide the airtight environment for the ANR system to function properly. ANR performance sould be degraded as much as 25-50% and the system will more likely to malfunction. The only acceptable replacement earseals are:

  • David Clark Gel Flo ear seals
  • AvComm gel ear seals
  • Flightcom gel-flo earseals
      If you do not have a replacement set, it is recommended that you purchase a set at this time. For you convenience, the David Clark and AvComm gel-seals can be purchased from ANR Headsets.

Figure 02

Step 2

      Inside each ear cup, surrounding the speaker, you will find two to three pieces of foam insulation material. The outer piece is usually a donut shaped. Use a pair of tweasers to lift the top piece of foam and gently remove foam insulation from the inside of the ear cup.

Figure 03

Step 3

      After you remove this outer donut shaped piece of insulation material, the speaker mounting screws will be visible. You will find one screw at the 10 and 2 o'clock position in reference to the speaker. Remove these screws and the original speakers from each ear cup.

Figure 04

Step 4

      Loosen the lock screws that hold the terminal ends of the input wires for each speaker. For David Clark headsets, the GREEN wire is the audio (+) and the BLACK is the audio (-). Identify and mark these two wires. Regardless of the color, in 98% of the headsets made, the audio (+) wire is the one which passes through the volume control. The other wire is the audio (-). If you have any doubts, use a continuity tester and refer to the diagram included with your kit.

* Exception: The FlightCom 4DX and 5DX series headsets have a different wiring arrangement. Refer the supplemental instructions provided with these headsets.

      Remove the remaining insulation materials from each ear cup. The oval shaped foam pieces at the bottom of each ear cup will be reinserted in Step 23.

Figure 05

Step 5

      The installation is simpler if the original crossover cable is removed from the headset. Start with the right ear cup and remove the retaining clamp. This is a very stiff clamp and is very difficult to cut. Pull the crossover cable to the inside of the ear cup so that you can have easier access to the clamp.

      It is more easily removed by grasping the retaining clamp on the with a pair of pliers and gently squeezing to enlarge the center and remove it from the crossover cable.

* NOTE: It is possible to use the original crossover cable. Since it is two wire conductor, the shielding wire may be used as the third conductor. If you elect to do this, make sure that this shielding wire is severed from the rest of the shielding network.

Figure 06

Step 6

      Gently remove the crossover cable from the right ear cup.

Figure 07

Step 7

      Pull it through the plastic tubing on the right headband, the head cushion, and left headband.

      Pull the crossover cable from the inside of the left ear cup through the exit hole. It is not necessary to remove the retaining clamp from the left end of the crossover cable.

      Note: Be very careful with the volume control terminals. They are very birttle and can be broken off easily if bent, especially on some David Clark models.

Figure 08

Step 8

      On the left end of the crossover cable, you will see three wires extending from the insulation.
  • GREEN: Audio (+) - Passes through the volume control.
  • BLACK: Audio (-) - Forms a common ground with others black wires.
  • CLEAR: Shielding - Soldered together with other shielding wires.

Figure 09

Step 9

      With a pair of wire cutters, cut these GREEN and BLACK wires about 1 1/2" from the end of the crossover cable.

Figure 10

Step 10

      Cut the CLEARshielding wire where it joins the other shielding wires of the main audio cable.

Figure 11

Step 11

      Tape the terminal ends of the GREEN audio (+) and the BLACK audio (-) wires of the left speaker.

Figure 12

Step 12

Installing the ANR Power Cable

      Using a pen or marker, mark a point at the base of the left ear cup to drill a 1/4" hole for the ANR power cable to enter the ear cup. Avoid drilling the hole on the very bottom of the ear cup since this area is thicker than the walls and may be too think for the rubber grommet which is provided with the kit.

      Starting with a 1/8" drill bit, drill a pilot hole on the thinest area of the ear cup wall, near to the main audio cable exit hole.

Figure 13

Step 13

      Continue to enlarge this hole until it is 1/4" in diameter. Carefully debur the edges of the hole with a small knife. Remove all debris.

* NOTE: This process is necessary to prevent cracking of the plastic ear cup wall.

Figure 14

Step 14

      Insert the 1/4" grommet into the hole. Then insert the free end of the ANR Power Cable provided with the kit into this hole. Pull it through until the 9 volt male plug on the other end is even with the main audio plugs or as desired for your cockpit needs. When complete, you need to have about 4-5" pulled through the inside of the ear cup. If you have an excess of this amount, cut it off.

      Secure the free end with a tie wrap as with each end of the crossover cable.

      Trim the installation from the free end of the power cable so that three inches of the RED and BLACK wires are exposed. The RED wire will supply the ANR Modules® with nine volts of power. The BLACK wire will be connected with other BLACK wires to form a common ground wire.

      Use a 16 gage wire stripper to strip and expose 3/8" of the RED and BLACK wires of the power cable. (Do not tin.)

Figure 15

Step 15

Installing the New Crossover Cable

      Insert the new crossover cable provided with the kit in the right ear cup. Pull the crossover cable through from the inside about 5". Secure this end with a tie wrap. Pull the crossover cable from the outside so that the tie wrap is near the inside wall of the ear cup.

      Install the crossover cable through the plastic retaining tubes, attach it to the headband and through the plastic retaining tubes on the left ear cup. Insert the left end of the crossover cable into the exit hole of the left ear cup.

Step 16

      Carefully study the wiring diagram provided in the instructions, appropriate for your headset. For illustration purposes, this wiring diagram is for the typical mono headset, with a single volume control on the left ear cup.

Change: Our latest power cables have red and white leads instead of the red and black as shown in these pictures.

Figure 16

Figure 17

Step 17

      The crossover cable which was installed in Step 11, contains four wires.
  • GREEN - Audio (+)
  • BLACK - Audio (-)
  • RED - 9 volt power supply
  • WHITE - Uses only for mono headsets with the volume control is on the right side. (If not needed, trim it off.)
      Carefully strip and expose about 1/4" from the middle (about 1 1/2" from the insulation) of the GREEN, RED and BLACK leads from the left free end of the cross over cable.

Figure 17

Step 17

      Refer to the diagram above and follow the following instructions carefully. This is the most difficult part of the installation.
  1. Wrap the free end of the of the RED lead of the power cable around the exposed center of the RED crossover lead. Then solder together with a 25 watt soldering iron and the solder provided with the kit.

  2. Use a 16 gage wire stripper to strip and expose 3/8" of the GREEN (audio +) wire coming from the volume control that was cut in Step 9. Wrap the free end of this GREEN lead around the exposed center of the GREEN crossover lead. Then solder together.

  3. Use a 16 gage wire stripper to strip and expose 3/8" of the BLACK (audio -) wire from the main audio cable common ground that was cut in Step 9. Wrap the free end of this BLACK lead around the exposed center of the BLACK crossover lead. Also wrap the free end of the BLACK lead from the power cable to this union. When secured mechanically, solder together.

* Change: Our latest power cables have RED and WHITE leads instead of the RED and BLACK leads shown in these pictures. If you want to keep the colors consistant throughout the headset, you may use the WHITE crossover cable lead as the common ground instead of the BLACK lead.

Figure 18

Step 18

      Using the head shrink tubing provided, cover the exposed solder joints from Step 17 above. Shrink the tubing with a match or cigarette lighter.

IMPORTANT! Avoid loose strands of wire. Cover all splices with heat shrink tubing and heat gently. Do not allow the flame to remain on the heat shrink tubing. Keep the flame approximately 1/4" from the tubing while heating. Remove the flame when you begin to notice the tubing begin to shrink.

Figure 19

Step 19

      For added security of these solder unions, insert another piece of head shrink tubing around the GREEN, RED and BLACK leads as shown in Figure 19.

Figure 20

Step 20

      Strip and expose 1/16" of each wire of the right end of the crossover cable with a 18 gage wire stripper. Then tin the end with a 25 watt soldering iron and the solder provided with the kit.

      Use this same procedure for the GREEN, RED and BLACK leads of the left end of the crossover cable, joined in Step 17.

Figure 21

Step 21

      Refer to the wiring diagram in Figure 15 above, and to Figure 21 to the left.

NOTE: It is important that these modules are installed correctly in your headset. If the RIGHT and LEFT modules are not properly placed on the ear cup as you wear them, the flange of your outer ear could interfere with the ANR pick-up microphone and a squeal could result. If you want to wear your microphone on the right side of your face, then place the RIGHT ANR Module® on that side and the LEFT module on the other side.

      Using a 25 watt soldering iron and the solder provided, heat the solder lands on the circuit board and melt a drop of solder over the hole each of the three the lands.

NOTE: The wires should not be inserted and soldered into these holes because they wires tend to weaken and break otherwise.

      Start with the RIGHT ANR Module®. The right module is indicated by a "R" on the speaker side of the module.
  1. Place the exposed end of the GREEN lead of the right crossover cable, flat on the left circuit board land and solder as indicated in Figure 21.
  2. Solder the RED lead to the center land.
  3. Solder the BLACK lead to the right land.

Figure 22

Step 22

      Solder the GREEN, RED and BLACK leads joined in Step 19 of the left crossover cable to the circuit board of the LEFT ANR Module®, as indicated in Step 21.

Figure 23

Step 23

Closing the headset.

  1. Replace the oval shaped piece of original foam removed in step four. Try to place it on top of as much wiring as possible to protect the ANR module circuit board.
  2. Pack the pink insulation inside the right ear cup around the crossover cable.
  3. Locate the two pieces of adhesive strips, included in the installation materials. Cut the two pieces of adhesive strips in half.
  4. Place a piece of the adhesive strip on the left and right sides of the inside flanges of the ANR Modules®.

Figure 24

Step 24

      Carefully route and arrange the wires so that they are not kinked or pinched as you place the ANR Module® inside the ear cup. Since these are very fine wire, they are easily broken during this process.

      Complete this same procedure for the left ANR Module®.

Figure 24

Step 25

      Place the felt pads inside the speaker opening of the left and right ANR Module®.

NOTE: These pads are necessary to protect the ANR system form the elements and prevent feed back (squealing) since the ANR pick-up microphone is in close proximity to the speakers. If you loose or need replacement for these pads, you may obtain a new set, free of charge, by contacting ANR Headsets.

Replace the ear seals.

NOTE: Gel-Seal type ear seals are manditory to insure top performance of your new ANR system. They not only provide better passive noise attenuation, but also provide the air tight environment required by the ANR system. They also increase the comfort of your headset. These may be purchased from ANR headsets or from most pilot supply stores.

Figure 25

Step 26

Securing the power cable to the main audio cable.

      To prevent tangling of the main audio and the ANR power cable, secure the cables together with the tie wraps provided.

  • Place a tie wrap about every 10" along the combined two cables.
  • Place a tie wrap above and below the splitter connector of the main audio cable.
  • Cut off the excess ends of the tie wrap.
  • To prevent snagging your cloths or skin, trim the corners of the tie wrap clamps with a finger nail clipper.

      That's it! Your installation is now complete.