Edifier R1855DB Sub Out volume problem (+T5 subwoofer)

If you&like to hear just the speaker sound, without speaking here it is: I have a problem with Edifier R1855DB Sub Out volume. It might be a common issue, since some people reported the same problem on reddit: UPDATE: Since Edifier didn&confirm that this is a manufacturing issue, not a design flaw, I returned both R1855DB speakers and T5 subwoofer. It might be incidental but I didn&want to risk it.