Usually it's harder to get high numbers out of sedans. Its just the design. I'm not familiar with the technical terminology but hatchbacks and coupes can get a lot louder easier. Bigger vehicles like SUVs can get lower because of the length of travel. Just imagine the car like one big enclosure. Its louder and deeper when you roll the windows down or open the front doors. 43hz isn't too bad. At least it's audible. Those 60hz guys sound like crap!