dethump !!!

For ten years end-users have been asking for a CEDAR algorithm that will remove extended low-frequency thumps. These sounds, often associated with large scratches on discs and blemishes on optical soundtracks, can be extremely long, and are not correctly restored using traditional declick methods.

Following more than a decade of research, CEDAR proudly announces dethump, an off-line package that fully removes and restores thumps of up to 50,000 samples duration. This performance (restoring one second of audio) places dethump in a class of its own. This is because all other descratch algorithms - whether implemented in real-time or as off-line processes - are limited to maximum restoration lengths of about 2,000 samples (1/25th of a second).

One of the dethump beta-testers was Ted Kendall, a former engineer at the BBC and now a freelance restoration engineer working with companies such as Teldec, Past Perfect, Hep Records and the BBC. He says, "Thumps have been the last remaining intractable problems in sound restoration, and traditional solutions such as applying a momentary bass cut have been far from satisfactory. What makes CEDAR's dethump invaluable is the ease of use within the SADiE3 interface, and the fact that it copes with the higher harmonics of the thump to produce a repair that is completely inaudible. I was bowled over because it did exactly what it said on the tin!"

Jim Gross, Sales & Customer Support Manager at Studio Audio & Video, supervised the introduction of the new process. He says, "We sent the first version of dethump to our most experienced audio restoration users and asked them to test it for a few weeks. When they reported back to us the response was uniformly fantastic. In fact it was outrageous... even the beta version worked faultlessly without any user intervention. It just got rid of the thumps."