Click, crackle & hiss removal techniques are used particularly on LP vinyl & 78 rpm records to improve the overall sound. Clicks and noises frequently spoil the listening enjoyment, especially old recordings.
Even with careful cleaning, your record will almost certainly contain unwanted interuptions, even new records contain minor clicks & pops. The degree of this interference depends very much on the condition of the record and previous use.
However, using digital technology it is possible to seamlessly remove 95% of these annoyances and leave you with a pure audio track. This service is not mandatory, but it is advisable unless your records are in mint condition.
Broadband noise can also be detected as surface noise generated by dirt and scratches in the grooves of a record or by tape deterioration and splicings. Analysis and removal of background noise such as electrical hum, tape hiss or machinery rumble can be acheived without removing portions of the source material. However, poor and badly recorded material with such defects as distortion, wow & flutter, drop-outs and very low gain are almost impossible to enhance to any acceptable standard.
The Concepts
There are an infinite number of processes that can affect the human perception of sound. For example, the live sound of an orchestra is dependent upon the venue, the audience and the local ambience.
So what is the aim of a restoration engineer? The archival viewpoint suggests that such an engineer should present the listener with the most authentic reproduction of the original sound that can be obtained. But what about the creative influence of the recording engineer?
With modern recordings, the ensemble sound often exists only on the recording medium, and many parts of it have probably never been through a microphone. Therefore the commercially minded engineer may, in contrast, attempt to generate a new recording more appropriate to its intended use. This use could be, for example, to please the public palate, or to represent accurately the sound of an era. Every restoration has its own criteria.
The algorithm designer is responsible for creating the facilities by which the restoration engineer generates new recordings from old. He or she does this by developing and implementing algorithms which remove unwanted sounds and/or effects present on the old recording.
CEDAR AUDIO provides a powerful set of restoration tools flexible enough to be used as the restoration engineer sees fit. However, it is my policy that the human ear should always be the final arbiter of sound quality; judgements based upon signal processing techniques are secondary considerations.
There are times when audio requires more than just simply enhancing ...
An old analogue reel of tape, for example, or an LP album of which only a few vinyl copies exist; vintage material from 78's or even earlier formats.
Shaw Sounds are superbly equipped to deal with such projects - we have sophisticated restoration software available including "Cedar Technology" with de-crackle, de-hiss & de-click algorithms.
We also have a full complement of vintage equipment for playback through 24-bit A to D converters for best transfer quality - this has made us a respected and successful facility.
We deal with all kinds of music projects from Classical to Popular, Choral to Jazz including spoken word and delicate historical archive material.
We believe restoration requires great sensitivity on the part of the engineer - just because we can remove the hiss in a recording it doesn't mean we should , the recording could loose "life" or "air" as a result.
Many restoration software programmes today can involve radical processing of the source signal like hiss, de-clicking & de-crackling - we at Shaw Sounds are careful not to damage the original material.
An intimate knowledge of our equipment and it's capabilities allows us to avoid the pitfalls of the process. An experienced engineer develops his own strategies and methods - tricks of the trade, if you like - along with an understanding of the needs of the material, help us achieve the best possible result.
Don't you get fed up with listening to music every day ?
Not really, in fact the variety is one of the things that makes the job so enjoyable - it keeps me fresh - and of course every recording is unique in it's own way." Whether the recording is new or old you have to make the same judgments, work out how the producer wanted it to sound on the domestic systems of the time, and make it sound the same way on the hi-fi systems of today. What makes the back-catalogue so enjoyable to work on is that some of those recordings have such a great sound; a depth and realness to them that people find difficult to achieve these days on a commercial CD !
John Shaw.
These are usually the most common requests
Removing clicks, pops and groove noise from records ( LPs, 45s, & 78s ).
Reducing broadband hiss from records, old reel-to-reel tapes and cassettes.
Re-pitching and correcting tone inconsistencies.
Making audio programmes louder, or balancing varied volumes levels.
Forensic restoration.
Converting mono recordings to stereo with spatial enhancement technology.
Remastering records to CD.
Isolating particular unwanted sounds from live recordings.
Editing and space adjustment between programme material.
Compiling and restoring different source tracks to produce a final master CD.
Conversion of analog and digital material to different file formats.
Reproducing the best quality of sound to CD
