New subUsing 100 Watt Yamaha which worked fine with prior unit. LFE output to sub with "Y" adaptor. The unit bottoms out with a " power vibration" at -5 volume setting.. I have receiver crossover at 80 and the sub LFE to off. I also tried the sub at near 150 and same results. It sounds like the type of "bottoming" you hear from the trunk of a lowrider and not a mechanical rattle like something loose. I'm 62 and do not need heavy bass or vulume, but this simply not adequate.....anyone know what I might be doing wrong here.....or possible sub defect?