06 Slice the raw recording into segments

First, have a look at the file

When you are ready to start processing the recording, I would suggest first having a look at its general condition. Of course, you would have got a pretty good idea of the quality during the process of recording, especially if you had taken the trouble of jotting down notes on the time points at which problems occurred: maybe a long initial empty stretch before the needle hit the groove, or a stuck groove, or some breaks which you re-recorded in another file, or certain very noisy portions. Here’s a suggested work flow to deal with it all.

Next, trim the empty bits

First things first: you need to trim off the leading empty stretch (the leader), taking care to leave a few seconds before the actual recording starts, so that you have a good stretch to capture background ‘noise’ if needed (like the ‘hiss’ in a tape). Believe me, if you’re doing a Beethoven, you will need it, as he is particularly challenging to record with alternating stretches of very loud and very soft sound. If the scratching noise in the quiet stretches is too obvious, you may have to try subtracting the noise at least in these quiet stretches (the background noise will usually not be noticeable in the loud bits).

To trim the leader in Audacity, you first load the .wav file you have previously saved (menu File/Open), and move your cursor position to the start (click on fast rewind, the double left arrow << in the control bar, just like any audio player).

Then position your cursor at the end of the stretch you wish to delete, hold down Shift and click. The stretch between the start and the current cursor position will go dark grey, in token of being Selected; then you click on the Cut button (scissors icon, but Ctrl-x and Del key also work) to delete that portion. There is another way to Select a stretch, in the Edit/Select menu: you can Select a stretch from Start to Cursor, or from Cursor to End, and do your stuff. The latter option is useful if you need to trim off any ending empty stretch in a similar fashion. Of course, you have to first position your cursor at the point in the recording that you want to work from (or to).

If the rest of the recording is good, that’s all you need to do, and  you can save the whole file using File/Export as a .wav file, giving it a suitable name that gives the composer, genre etc. (the original file can have the tag –raw.wav, the modified can have the tag –fixed.wav, as suggested in a previous post).

Break the file into (2-minute) bits using Snap-To

If, as is more likely, you would like to improve the recording, one of the most helpful things you could do would be to break up the file into little bits; I like two-minute sections. There are many advantages in doing this, and dealing with each section separately. One is that loading, processing, saving the files become much faster, so that you can achieve some progress even in a short sitting. Secondly, if you goof up somehow (deleting the file, for instance), or the computer hangs, you will only loose the current two-minute bit, rather than the entire work. In fact, if you load and try to work on a long file, chances are that the system will hang or crash; so dividing it into small bits is helpful even if you have all the time (and patience!) in the world.

There is a very nifty feature in Audacity called Snap-To (on the Edit menu), that is enormously helpful in doing the `slicing’ precisely. By turning Snap-To On, the cursor goes precisely to a full number on the time line (minutes or seconds, depending on how zoomed in you are). You may have to experiment a bit with zoom levels to ensure Snap-To to goes to a full number of minutes, such as 2:00, 4:00, and so on. First, load the whole file (with trimmed beginning and end, as described above), turn on Snap-To, position the cursor near 2:00 (miniutes), which should pull it exactly to 2:00, then on the Edit menu choose Select /Start to cursor, then File/Export Selection to save this portion as a separate file. Next, Select from 2:00 to 4:00, go through this cycle repeatedly till the whole file is done. You will name the files name-01.wav, name-02.wav, etc.

Now you can load each section separately and do whatever processing you need, and Save the corrected files as name-01-fixed.wav, etc. To put them all back together, you will have to File/Open the first one, move the cursor to the end (click on the button for Fast Forward >> as usual), then Open the second file in a second window (use File/Open), then select the whole of this second section by Edit/Select All, then Copy the selection (the usual Ctrl-c works!), switch back to the first file, Paste (Ctrl-v works), then move the cursor to the end of the appended bit (Fast Forward >> again!), add in the third file, and so on repeatedly. The only thing to look out for is not to miss any file in the sequence, and to do it carefully and systematically. Finally save the whole thing with a name-fixed.wav filename. Of course, it will be advisable to save the interim file after each step!

What processing to do on each bit (click removal, noise removal, etc.) will be discussed in the next post.

05 Capturing the sound output

Now that you’re all hooked up (see previous post), it is time to start capturing the sound from the grooves. Switch on the computer, start up Audacity, hover your mouse pointer next to the red REC circle in readiness to start the recording. Turn on the turntable with the LP on it, check the cables, and then in sequence, start the recording on Audacity and drop the needle onto the groove (gently, gently!).

If all is well, the sound should be heard on your music system (if you’re using one as receiver), and the computer (you can turn down one of them). The incoming sound will be depicted as a wave profile in the Audacity screen (two channels for stereo, only one if it’s recording in mono). The wave profile shows the amplitude of the sound wave (loudness), and you can see that it reflects the up-and-down oscillation of the signal, which is translated into the back-and-forth oscillation of the surface causing the sound (your speaker diaphragms, your ear drum membranes and tiny bones).

You will also see sudden spikes mirroring the abrupt clicks or bigger ‘thumps’ which are normal with records. These are the scratches, clicks and thumps (hiss, crackle and pop!) that you will be reducing or eliminating using the software. These are usually seen mostly on the outer centimetre or so of the record (that is, at the start of the playback), probably because most of the handling is done at these edges, the needle has been dropped on the outer edge more times than the middle (maybe even pushed by jerky movements), and possibly more dust has collected on the outer edge even as the LP lay dormant inside its jacket. Of course, if the LP has been maltreated, kept horizontally and badgered around, or (shudder!) kept naked without its inner polythene and paper slip cover, or outer jacket, it will probably show visible scratches on its surface.

If the sound is very bad even after the outer centimetre or inch, it may be worthwhile to stop the recording and take the plate off the turntable and closely examine the surface. Perhaps there is some goo or gunk adhering to it in places, which may even cause skipping of grooves or the dreaded endless loop on the same groove (like a stuck record!). A little cleaning may be called for. As an old hand at this game, you probably have your own favoured methods of cleaning, starting with blowing or vacuuming (but beware of adding new dust and grit as you are taking the old off!), wiping with a wet cloth, and even using cleaning liquids (isopropyl alcohol; or your favourite drink if nothing else is around). I gather that alcohol is not good for old records made of bakelite or shellac, but is ok for later plates made of synthetic material (vinyl) (apply liquid to cloth and cloth to LP, test on  a corner or in the centre to make sure it doesn’t dissolve the material!). For a particularly greasy old LP, I have even used detergent and held it under a stream of water from the washbasin! I won’t divulge the other stuff I’ve tried to reduce the crackle for very bad surfaces, but it involved water or alcohol to dislodge gunk in the grooves and baby oil to lubricate the needle movement. I believe a drop of liquid at the needle facilitates smoother floating, which may help it to overcome small abrasions or dents. If you do try this, it should be done first on an experimental basis with a useless record, and try to apply it only at obvious problem spots. These can be located by looking at the surface at  a low angle with grazing light, which will show areas where some stuff has lodged in between the grooves or on the surface.

Now here’s a suggestion on the general strategy, the ABC (triage) of rescuing the recording. If there have only been a few glitches at the start – say, a couple of spots with large clicks, or one or two small patches with a recurrent click or scratchy reproduction – and the reproduction settles down after that, I would suggest allowing it to play on. This is because the dust settled into the grooves may get loosened and dislodged at the first playback, and you can then go in with brush and blower to root it out for the second run which may be much better (and do blow or brush from below, so that the dislodged particles float off into space rather than settling down again on the surface).

A good part of the recording may actually turn out quite fine, especially the whole of the second and subsequent tracks. Even if a part of a track is good, the second run of the recording can be restricted to the defective parts, and the concerned bits spliced together digitally in the software. So if the bulk of the recording is going on well, let it continue to the end. Then stop the recording and turntable, and save the raw file as it is, giving it a useful name such as beethoven-concerto-violin-Perlman-side01-pass01.wav or something. Organize your files by subdirectories from the beginning (you could use recordings\beethoven\concerto\violin\LPnumber for instance) to avoid going crazy later (no nonsense of “everything is miscellaneous”, see here).

You don’t have to record the whole side in one file. If you have to pause the recording for some reason, lift up the needle gently and stop the recording there and save the file as …\part01.wav or …\track01-03.wav something. Anyway you would probably like to store each track as a separate file on the computer.  Good, bad or indifferent, just save the file and carry on.

If the recording is really bad, however, like if there are too many jumps or stuck grooves or interfering sounds (sometimes the computer beeps are added to the recording!), then it may be better to abort the recording to save overall time. If the recording is very bad, it could be abandoned in its entirety, or if some tracks are good, just those could be saved. Then attend to the glitches (clean the surface, switch off cellphones, for instance) and redo the recording.

One trick to overcome repeating (stuck) grooves: by applying a slight pressure on the stylus head (put a small card on it or press down very lightly with a card), it may be persuaded to get over the defect and carry on. Don't overdo the pressure, because it may lower the speed audibly and spoil the recording. If you catch the stuck groove immediately it happens, probably the best thing to do is to simply carry on with the recording, and attend to the defective portion in software later.

If the record is really really bad, it may be best to forget about it. In any case, I would recommend looking up the album on the web, in case there is a downloadable version already (always making it clear that we are not encouraging copyright violation), and in fact that may well be the first thing you ought to be doing, unless you’re taking it up as a challenge or a learning experience. Small defects however need not upset your rhythm: there are ways to deal with these in software, including some slight cheating which should not detract from your pleasure in the recording. More on these matters later!