Hi. I have this unit https://www.aliexpress.com/item/100...r_list_main.45.460c1802qHvxch#nav-descriptionMy car doesnt have factory amp. I connected the sub amp to headunit with Y splitter. The subwoofer loses volume when I increase or decrease the volume.For example, I set the volume to 30. Everythings perfect, sub slams. But if I turn the volume down to 29 or up to 31, major loss of volume. And if I mute and unmute the headunit, then...Read more