Why is there no bass in the audio with the iBolt dock and my Samsung Galaxy S4?

[Shmuby]

I also posted this question on Stack Exchange, here.

I'm using my Samsung Galaxy S4 with the iBolt car dock. It comes with a USB cable that splits into USB (for charging) and a 3.5mm jack (for audio). When I use this setup in my car, the audio has no bass at all. I believe it is literally just a high pass filter. I contacted iBolt about it and they claimed that they are just using Samsung's dock audio feature.

In order to get the audio to play at all I do need to check off Settings->My Device->Accessory->Audio output mode (indicating that it should use external speakers when docked). So this supports their claim that it is a built in Samsung feature.

I can think of many reasons why this might happen. It would make sense for the phone to have a high pass filter to protect the internal speaker. Maybe that filter isn't being turned off when the audio is output over USB.

I've also tried a standard 3.5mm audio connection and a Bluetooth A2DP adapter with a 3.5mm connection on the same phone/car, and the bass sounds fine.

Is this a Samsung bug? Does iBolt's cable not work properly? Is there a work around?

Thanks in advance,
Shmuby

 

[RiP2]

I have the same problem, same here too:

head-fi org/t/689100/3-5-mm-jacks-4-vs-3-conductors
tomsguide com/forum/id-2166958/bass-output-subwoofer-galaxy-star-pro.html

I have Samsung J2. It works great with any 3-pin/4-pin headphone but doesn't work with PC speakers, almost no bass, something like low pass filter.
Other phones like S3 mini, S2 Plus don't have this problem.

Any idea?