Here is an interesting posting taken from alt.binaries.sounds.mp3.jazz on usenet. One user is responding to another's posting giving an overview of his LP cleaning procedures:
RE LP Ripping:
I have attached my comments to those from JazzSir
@ comment @
On Sun, 10 Sep 2006 07:09:43 GMT, "JazzSir" <JazzSir@YessSir.com>wrote
>Hi,>
>I will describe my procedure with argumentation. You can then take out of it what you need.>
>1. The main imported thing about my audio part is a good amplifier with an md output to the computer line in. The recordplayer must be grounded to minimize noise.
@ Total agreement, but make sure all other sound card inputs are disabled when recording @
>2. I record each side of the lp completely as wav-file with Cool-Edit.
>3. The next step is visual editing of the wav-files for bigger clicks in Cool-Edit . It is preferable to make the cut in the wav-file not bigger than 3 millisecs otherwise the cut itself might be heard.
@ Some clicks can be removed this way, but careless cuts can result in more unwanted artifacts, depending on the type of click, one must completely cut the "aftershocks" which can cause a low frequency thump. Being a mechanical mechanism, the groove and stylus have an inertia, once the stylus is seriously disturbed by a foreign object in the groove it can take quite a time to recover normal momentum, large under & over swings will occur after the original disturbance, all these peturbations must be removed, but carefully
@ Personally I use Sound Forge to do this, manually editing the waveform with the pencil tool, this in my opinion, is a much finer way of removing clicks, and with experience you get to recognise what various waveforms should look like, by comparing with those adjacent to the one you are working on >
>4. The next step is normalizing in Cool-Edit to 110 %
@ NO NO NO it is best not to alter the dynamics in any way BEFORE you take noise prints @
>5. The next step is basic filtering in Cool-Edit. For this you go to noise reduction and prepare a filter of a piece of the wav-file between numbers that looks representative of about 2 seconds. With live LP's you can only take parts at the beginning or the end of the complete wav-file. The reason is that when there is talking in the background of your filter it gives a very strange distortion. You apply this filter on the wav-file and save the wav-file afterwards. It is advisable to make a new filter for each wav-file.>
>6. For the end-filtering I use an old version of WinOnCd before it was bought by Roxio. The denoise filter of this program is really marvellous. It makes the sound warmer and fuller and it takes away most of the small distortions.>
>7. The next step is to cut the wav-file into pieces. I use the program Goldwave for this because the split functions is very easy. But any other program will do.
>>8. Now comes the final phase. Each number gets a final editing in Cool-Edit . At the end of the number the tail part containing no music must be deleted. At the beginning of the number I plays 1 second of absolute quiet. This is to give the idea that it is a very clean recording. And a last visual check of no clicks were forgotten.
@ THIS IS THE PLACE to do any changes to the dynamics (Normalise if you must) but remember to keep the track volumes, relative to each other, and similar to that of the original, all part of the production of the original album (Soft tracks, Loud tracks) @
>9. Now the number is ready to be converted from wav to mp3. As these are all analog recordings 160kb is more than sufficient for the conversion.
>@ Not in my findings, unless you have made serious changes to the spectral response of the recording (possibly ruined it). The frequency spectrum of a good LP and pickup combination exceeds that of the CD medium, in that it has NO precice cut off (21-22 kHz) but can reach 30kHz or more, so retricting the available spectrum by using a low bit rate of 160 is wrong. I favour 256k at least, or a high quality VBR setting (Using Lame, see the various sites that cover that utility (Google) @
>In this way the digitizing of an LP takes about 2 hours. >Have fun.
>Greetings
>JazzSir
@ Thanks JazzSir, and interesting and de-mystifying article, I trust you will take my comments in the spirit they were meant. I would like to add a point or two here that may help others that feel they cannot go to these lengths. There are a few of us that have done LP cleaning for many years, and are probably willing to do interesting & rare albums for the benefit of all, if that is the case, and you have top notch LP playing equipment but are not prepared to attempt the cleaning yourself, then supply the side rips as they are, with all noises plus lead in-outs, but use the highest bit rate you can (256/320) and plain stereo NOT joint stereo (check your MP3 encoder settings). This will produce a rip that has the highest spectral content possible, so all the clicks will be pristine and not lengthened by the filtering in the low bit rate MP3 process, this allows an easier detection and removal by another person. One final comment ... A Real clean LP is much easier to restore than one with dust and finger marks on it, but beware cleaning cloths, they can add more small noises than they remove. The real way is wet cleaning, and centrifugal drying. Again GOOGLE will come to the rescue for help on this topic. @
Spas.