Replace Wireless soundbar subwoofer with Active Subwoofer


Distinguished Member
Hi Guys,

There is a member at AVS Forum who had successfully integrated his active subwoofer into his LG soundbar by doing the following:

I am wondering if we have any engineers out here who can do these sort of these things it appears to be couple of man hours of effort with the right tools in place.

Please can someone advice me on this front.


Proceed at your own risk:


- 40 watt soldering iron

- .6mm solder

- Heat shrinkable tubing kit and / or electrical tape

-Small flat head screw driver

-Small Phillips heat screwdriver

- Good pair of small wire cutters

- Few feet of 18 gauge wire

- RCA cables long enough to connect the LG sub to your new sub

- Speaker-level to Line-level Adapter -


- YouTube videos on how to solder. Practice with a few small pieces of the 18 gauge wire. Do not perform any disassembly until you feel proficient soldering wires.


- Unplug LG sub from power outlet

- Remove back of LG sub by removing the Phillips screws in the back of the unit

- With small flat head screwdriver gently pry the plastic back off. Be careful as there are two small wires that are attached by a clip to the amplifier on the plastic back. Put plastic back aside

- Remove the two speaker wires that are clipped to the woofer and note polarity - red has to go to the larger pin towards the top


-Cut a piece of speaker wire to a length of 2.5ft-3ft. And strip insulation exposing 1/4 inch of wire and tin it with some solder. Take a small length of heat shrinkable tubing and place in on the wire - away fro the exposed metal

- Now bend the speaker around the base of the clips that go onto the speaker. The base being the lowest part of the clip so it won’t interfere when you clip

- now solder the speaker wire to the clips. Copper color on red speaker wire - silver to black. Place heat shrinkable tubing over the area you soldered and heat it up.

- reconnect the clips to the speaker

Now you will attach the speaker line level adapter the plastic back - between the amplifier (looks like a circuit board) and toilet paper looking cone. Line it up and mark where you want to drill one or two holes (3/8) to let the cables enter so they can attach to the rca outputs . If your sub only has one rca input or you plan to run a y splutter then you need only one hole. I think using both rca outs And two cables are best though. Another option is to run the cables out the paper port instead of drilling holes.I wrapped the cables around the paper cone twice and tapped them so they would not pull out. I recommend some Velcro or strong glue to attach the line level adapter to, the plastic back.

Now attach the other end of the 18 gauge speaker wire, you soldered, to the adapter by pushing the bare end of the wire into the plastic clips. If you plan to run two cables then strip two more small pieces of wire and make 2 little jumpers where one pair go in red and green and the other to black and white.

Now reassemble the speaker but before you do make sure all the wires are still connected - those that clip onto the woofer and those that attach to the speaker input clips on the adapter.

Now connect the rca cables, coming out the back of the LG woofer into your other sub, make sure it is still powered off.

Turn on the LG sub and make sure it is wirelessly connecting to the sound bar and it is working correctly - sound comes out. At this point you can tun on your external sub , low level ad determine if you can hear anything. Turn it up slowly to verify sound.

I recommend a 90Hz crossover for best integration of the two subs.also. Also set the woofer volume in the LG app to-3 or less. It will really clear u the congested lower mid range.


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