Custom made 4.4mm TRRS with JH Socket without base control

  1. choisan
    Hi, I ordered a set of 4.4mm IEM cable for my JH Audio's Lola to use on my Sony WM1A. It is without base control. Before that, the guy asked me to use the tester to test the connectivity on my original 2.5mm balanced cable and my Moon Audio 4.4 Black Dragon.
    My measurement are as below.
    jh connector.jpg

    HOWEVER, the measurement i have on the newly received IEM is different to what i have with my Original or Moon Audio.
    The guy said the connection was based on the suggestion of soldering a 50ohm resistor inside the plug as below Point 1 to Point 6 (8 wires)

    i. May i know if there is anything wrong with my new IEM cable?
    ii. Should i use my earphone to test it?

    1. Sirens series requires you make accomodations for bass adjustment. They naturally have +15db tuned bass, then use selective reduction to achieve the desired bass level. If you don’t use any adjustment or resistors then the IEM will have the “max” bass setting on your stock cable. We don’t prefer the use of a “bass controller” as their parts can wear out pretty quickly and require replacement, although you can find these bass controllers on Lunashops. Instead, we recommend that you pick some 50 or 25 ohm resistors, rated 1/4 watt – we will provide a few links. For a 6 wire cable, you are using 2 wires for bass (left bass, right bass), 2 wires for ground (left ground, right ground), 2 wires for mid/treble (L+, R+). For an 8 wire cable, you are using the same except 4 wires for mid/treble – a pair for each. As per the JH patent there is no need to separate mid/treble into 2 separate wires as both are connected to the same point on the 2.5mm or 3.5mm amplifier plug – they both connect directly to L+ or R+. As such their 2 contact pins can be soldered together on the CIEM plug, then just solder the 1 or 2 mid-treble wires for that channel to it.

    2. This connector’s lock nut and barrel both thread over the threads on the insulator. Simply insert the connector into your iem, then unscrew the barrel and nut. Slide the barrel, then the nut, onto the earcup wire of your IEM cable in progress.

    3. For a 6 or 8 wire cable, you need to solder small resistors to the R+ and L+ contacts of the amp end 2.5mm or 3.5mm plug. This will test all your skills as a cable builder. We recommend soldering the resistors, then permanently securing them with a tiny bit of glue so they do not fall off in later steps when you must solder 2 things to one contact point. 6 wire is the easier cable to build by far. We recommend either the Eidolic 3.5mm rhodium plug or the Eidolic 2.5mm plug for this project. Here are links to the best resistors:

    4. For a 4 wire cable, you must use SMD resistors inside the IEM end plug. Simply place one in between the 4 contact pins, it will sit in there. It has solder contacts on both sides of its base and top. You can secure it with a tiny bit of superglue to the insulator’s plastic if you want. On the side with the mid/treble pins, simply solder on both sides to connect it to both pins. On the side with the bass and ground pins, only solder it to the bass pin, avoiding the ground pin. Then, when it comes time to solder the cable to it, solder the L+ or R+ wire to the mid/treble pin area. The signal will flow normally through to the mid/treble drivers and then through the 50 ohm resistor to the bass driver, setting the bass to 50%. Easy.

    5. We recommend braiding the cable after labeling/marking the left wires, and routing them through their side of the y-split. You need only keep the left wires and right wires separate, no need for detailed markings. Tin & identify the wires at the top of the cable. For 6/8 wire cables, one wire should read 50 or 25 ohms when checked with a multimeter connected to the L+ or R+ contact of the 2.5mm or 3.5mm plug. These are your “bass” wires and solder to the bass pin. To the L+ and R+ contacts there will be 1 or 2 wires per channel that read very low resistance, these are your mid/treble wires. These solder to the mid/treble pins together. The remaining wire is your ground wire for that channel.

    6. Once the barrel and nut are threaded onto the earcup wire, solder your two mid/treble wires together as one for easier soldering (8 wire only). Solder the two mid/treble pins together with a little bit of solder. Connect the mid/treble wires. Identify your ground wire and solder that, then finally the bass wire. We recommend tinning all 4 pins gently before soldering.

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