In the search to improve my speaker performance, I came across a company called Perpetual Technologies (http://www.perpetualtechnologies.com) who produce a device which seems very interesting. They claim that by putting their device between the digital source and the DACs, they will re-clock the digital input to remove jitter and other digital artifacts, and correct the phase and frequency response of your speakers to near-perfection over your speakers' useful bandwidth. They have downloadable algorithms for most speakers, or offer a facility to calibrate it yourself. They even claim to be able to correct problems in the room itself, and all for approx. US$1,500. Impressive claims; has anyone heard of them or had any experience with their products?