General filters and noise reduction algorithms are not in my toolbox, not for editing and not during playback . I only touch blemishes, which are noticeable. And I touch them gently, like dusting away the flaws, and when you dust, it tickles. That’s why Tickled Tangos.
Clicks, I remove one by one. Equaliser, I only use during small sections, where shrieking hurts my ears, the bass is too rumbling or when there is a lack of midrange.
During dusting, I periodically backup my work, so I don’t have to start all over again, when 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 record medium and technology but also because of the capacity of the sound reproduction systems, 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 sound engineer, I was in the midst of it… part of this 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 signal-to-noise ratio of an old ‘virgin’ vinyl was about 45dB, at good times, tapes about 60 to 70 with CDs soaring at 96dB.
Current Re-mastering Methods
In order 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 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, they were recorded at a higher intensity to compensate for the losses during reproduction.
With the advent of subwoofers (we built one in a 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” system.
Finding the RIGHT Compromise
My strong ‘Arty’ side helps me here. Having a sense for rhythm and sound keeps me in line. But more so, 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 and time.
Through my work I feel the spirit being freed. If this sense of liberation progresses, then I know, I am on the right track. If not, then I back paddle until it feels right again.
Feel the spirit (force) had been around before Star Wars. It can’t be measured, yet, but it can be felt.
If you want to read on… it’s getting technical
Excessive high frequencies are often accompanied with a faster beat caused by a higher playback speed of the record. A frequency spectrum analyser provides the frequency distribution and the tonal key. Often is not the key it has been composed in.
If I can find the original key, (which is often half a tone lower, sometimes more) I reduce the speed and often the result is sufficient. If a piece appears still too fast (too uncomfortable for dancing), the tempo can be reduced to up to ten percent without loosing sound quality and remaining in the same key.
If I can’t make up my mind, I dance to it.
The frequency distribution levels tell where signal strength was lost during recording or distorted through mechanical wear of the record medium. Going through the recording, I gently amplify or dampen sections individually, 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, larger ones I copy over by an identical good section in front or past it.
Sections with crackles I reduce first with a low pass filter. If this is not enough or the section is too long or badly damaged, I look for the same section somewhere else in the piece (luckily many Tango pieces are repetitive) and bingo.
I have also started utilising the significantly increased dynamic range of digital recording (the range between the quietest and loudest sound capable of being recorded). Not only do I emphasise the beat but also increase the sound level at specific section where and when appropriate.
How long does it take to dust a piece?
An easy peesy piece about half an hour. This would include a general adjustment of the playback volume to about .5 to 1 dB below the maximum, or whatever I find appropriate for the kind of music and adding a length of silence at the start (half a sec) 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 I don’t like needing to adjust the volume. I find it annoying, as a dancer as well as DJ.
A medium challenge takes about two hours, including 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
Amadeus W T