I have a 2011 Tahoe which has absolutely 0 bass in the sound....supposedly the 21 Yukon has a subwoofer somewhere. Those that have a 21 Yukon, is there any bass to the audio, or is pretty flat? I sat in a 21 briefly and played something with the doors open and I didn't hear much bass at all... compared to my wife's Volvo which has a subwoofer, it actually has a nice thump.