General filters and noise reduction algorithms are banned from my toolbox, not for editing and not during playback. I only touch up blemishes, which are noticeable. And I touch them gently, like dusting away flaws, and when you dust, it tickles that what you dust. That’s why Tickled Tangos.
Clicks, I remove one by one. The equaliser, I only use during small sections of a few seconds in length, where shrieking hurts my ears, the bass is too rumbling or when there is a lack of mid-range.
During dusting, I periodically backup my work, so I don’t have to start all over again when my dusting got too heavy-handed.
Sound Recording History
In early music recording history (up to the 1950th) most of the recorded sound was in the mid to high-frequency spectrum. Not only because of the limitations of the recording medium and technology but also because of the capacity of the sound reproduction systems could not handle more, namely the amplifier and most of all the speakers.
Speakers have always been, and even they have come a long way, they still are the weakest link in the reproduction of sound. In the late sixties, as a sound engineer, I was in the midst of it… part of history.
In comparison with current CD fidelity, records had a quarter of the frequency storage capability as well as only about half of the dynamics (the range in which the quietest and loudest sound can be recorded and played back). The signal-to-noise ratio of an old ‘virgin’ vinyl was about 45dB, at best, tapes about 60 to 70dB with CDs soaring at 96dB. For more detail look here (on this page)
Current Re-mastering Methods
To gain more sound (dynamics) when remastering an old recording, the record was often sped up by up to ten percent. You may have wondered why many of the tenors have such squeaky voices and the violins are squealing. Therefore, the rendered music ends up at a wrong pitch and what’s worse, sometimes at a speed too fast for comfortable dancing.
Records and tapes had insufficient bass recording capacity, and older playback systems were inefficient in reproducing the lower frequencies. Therefore, the bass was recorded at a higher intensity to compensate for the losses during reproduction.
With the advent of subwoofers (we built one in the lab in the late sixties), this was not necessary any longer. Therefore, when older recordings with their overemphasised bass are played back through a system with a woofer, too much bass is produced.
Reducing the bass volume is one of my jobs. This is the reason why some of “my” music may sound a bit tinny when listened to through small computer speakers. They will be ok in your “normal” speaker system.
Finding the RIGHT Compromise
My ‘arty’ side helps me here. Having a sense of rhythm and sound keeps me in line. But more so, some music can inspire me. It is my reason for dancing. I work on a piece because I feel its spirit, which has been somewhat covered by debris of wear over time.
Through my work (tickling the Tango), I feel this spirit being freed. If this sense of liberation progresses, then I know, I am on the right track. If not, then I back paddle through the stages of saved versions, until it feels right again.
Feel the Spirit (force) had been around before Star Wars. It can’t be measured, yet, but it can certainly be felt.
It’s getting technical
Excessive volume and occurrence of high frequencies are often accompanied by a quicker beat, all these effects can be caused by a playback speed of the record faster than intended. A frequency spectrum analyser provides the frequency distribution and the tonal key, the key at which song is heard. Often is not the key the song has been composed in.
If I can find the original key, (which is often a semitone lower, sometimes more) I reduce the playback speed, which also reduces the pitch and often this change is sufficient. If a piece still appears too fast (too uncomfortable for dancing), the tempo (no change in pitch) can be reduced to up to ten percent without losing sound quality.
If I can’t make up my mind, I dance to it, this will tell me.
The frequency distribution levels of a section of a song tell whether signal strength was lost during recording or distorted through mechanical wear of the record’s material. Going through the song, I gently amplify or dampen sections individually, mostly only certain frequencies, always checking the consequence.
Lastly, the most tedious work, the removal of the noticeable crackles and clicks. They have to be taken out one by one. Small clicks I just cut out; they are only milliseconds long. They can be heard but taking them out does change the beat minutely but it is not noticeable. Larger, longer clicks I replace (copy over) by an identical undamaged section from within the song. Luckily, Tango music is somewhat repetitive.
Sections with crackles I reduce first with a low pass filter. If this is not enough or the section is too long or severely damaged, I use the same method from above, copy and paste from an intact part.
I have also started utilising the significantly increased dynamic range of digital recording (the range in which the quietest and loudest sound can be recorded). Since I know what life music (without amplification) sounds like I can judge when to emphasise the beat and even increase the sound level at specific sections where and when appropriate.
How long does it take to dust a Piece?
An easy peasy song takes about an hour. This would include a general adjustment of the playback volume to about .5 to 1 dB below the maximum dynamic range, or whatever I find appropriate for the kind of music. I also add silence at the start (a second) and end time (about 5 sec).
Why am I doing this? When I dance, I like a short break between the music within a Tanda. And as DJ I don’t want to adjust the volume.
A medium challenging song takes about two hours, including the variation of pitch and tempo as well as specific volume adjustment and a few crackles.
And a tricky one… the longest took me around ten hours. I only do this if I really, REALLY, REALLY like a piece.
Makes sense? The main thing is