I have recently put a pair of the Heartsound Lotuses (basically a new product that is a black box but much larger than the Holostages) into my system and they are great. Just all around NOTICEABLE improvement to my system. You will need to buy RCA male to male interconnects to connect each of them to a spare interconnect input on your amp or other component. The improvement for a pair of the Lotuses to me is more profound than that of a whole set of holostages in my system. Also, I'd say better than the Heartsound Ground Box, too....which I also really liked. After inputting them into my system I really noticed the density to the images and the bass boost making the whole sound seem more substantial and meaty while at the same time more detail and pretty much every aspect of the sound improved. I think this is Heartsounds best product yet. The most bang for the buck in my opinion!