Dethump - a totally new restoration process

CEDAR Dethump

30 July 1999

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 methods.

Following a decade of research, CEDAR proudly announces Dethump, which restores problems of up to 50,000 samples (1 second) duration. This capability places it in a class of its own because all other descratch algorithms - whether implemented in real-time or as off-line processes - are limited to maximum lengths of about 2,000 samples (1/25th of a second).

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 says of the new process, "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 its 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, 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."

The first Dethump order was placed by and delivered today to Whitfield Street Recording Studios, London, UK.

For further information:

CEDAR Audio Limited, 9 Clifton Court, Cambridge, CB1 7BN, United Kingdom.
t: +44 1223 414117
f: +44 1223 414118
e: info@cedar-audio.com