Okay, I have 2 amplifiers in my truck. One powers the subwoofer and 4 door speakers. The second powers 2 tactile transducers, 1 mounted to each of the front seats. I have remote volume control of the subwoofer because that feature is built into the amplifier itself (Alpine PDX V9) but I would like to control the "volume" of the tactile transducers.

The head unit has 3 pairs of RCA output: front, rear, and sub. They are all connected to the PDX. The amplifier for the seats has high level inputs and I am using what would normally power the door speakers from the head unit to get signal to that amp. In theory I could buy a high level to RCA converter and then use that to get signal to the amp and either buy one with volume control functionality built in (expensive and would control both with 1 knob) or hack the RCAs to put potentiometers in line. I do not want to do either or those options.

Ideally I would like to put something like potentiometers inline between the headunit and the amplifier to control the volume to each of them individually and keep the wiring to the controls as far forward as possible. I have enough wires running front to back in there already. Is this possible, and if so what should I use?

Thanks in advance.

  • 1
    I'm voting to close this question as off-topic because it belongs on electronics.se and should not have been migrated.
    – Nick C
    Oct 12, 2016 at 18:54
  • 1. See if the amp has a remote volume option. 2. use RCA splitters to get the sub signal to both the subwoofer amp and transducer amp. Then use the headunit to control them in tandem.
    – cory
    Oct 12, 2016 at 19:16
  • Car Audio is on topic here. Although one of the audio or sound site might have better answers. Oct 12, 2016 at 19:29
  • This should not have been moved. It was apparently a mistake to use the words "car" "audio". Its the same theory as if it were in a house, except its not in a house. Oct 13, 2016 at 3:33

3 Answers 3


If you don't want to break out to RCAs, there are two options left:

  1. Find the input gain on your amp, desolder or bypass it in some way, and run remote wires from it to a potentiometer. Bonus points if you reuse the amp's pot.
  2. Use a stereo L-Pad, which will attenuate the signal without changing the impedance.

Remember that when you're running up to 50W through a pot, that pot needs to be pretty big, so L-Pads are pretty big. A stereo L-Pad actually has 4 large pots internally, so it's almost comically large for a car stereo install.

  • I'm going to desolder the pots and run wires to the dash. I haven't decided where or how to mount them yet, but that seems like the most "fun" way of doing it without buying 2 AudioControl LC2i. Jan 15, 2017 at 18:20

What you need is an RCA inline volume controller.


  • Thats great except I would have to split the RCAs that are going to my 5 channel amp, or still get a high level to RCA converter which already has the same functionality as the "RCA inline volume controller" which is essentially a potentiometer attached to a small circuit board so that input and output RCA cables can be attached. The same thing could be done by cutting and stripping a RCA cable. Input goes to potentiometer, potentiometer sends attenuated signal to amplifier, sound decreases. Oct 13, 2016 at 3:38

Does your headunit allow you to control the sub volume separately? Most units do. If that's the case, get some RCA splitters and split the RCA sub output to feed both the subs and the shakers.


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