There may be many reasons.
The closer we are to the begining of the signal path chain the more important the element is.
So by begining from artist's brain to listener's brain...
1. Artists must have had good mind and physical condition.
2. Songs were well orchestrated to leave frequency space (gap) for the voice. Also the use of non ordinary musical intervals from bass to melody enhances melody. Intervals different from the ordinary 1,3,5 which define major or minor as explained in the Bach - Neidt figured bass code were often used. For example California Girls - Beach Boys using B bass with A major ie B(2,4,7). The song written in the key of B major progresses from B(1,3,5) to B(2,4,7).
3. Rooms had great acoustics. We can see for example at the back cover of Pet Sounds acoustic panels, membranes. They were designed by Bill Putnam. A guess is that they should have had an elastomer material to deflect by vibration as sound strikes. So bass is converted to beat and therefore absorbed. Poly cylindrical diffusers were used for bass absorption and diffusion of sound. Real echo chambers and steel plates were used for reverb. Tape recording reproduction was used for echo.
4. Great microphones of every type were used. For example U47 condenser, RE-15 moving coil, 77DX ribbon. Proximity bass was cut by an internal inductor (coil) connected across the output (Pleiades filter). These inductors were also electromagnetically damping the membrane for plosives and air blasts, (Lens's law in physics).
5. Backing track acoustic intensity input to singer's ears must have been low, helping them to sing in tune. (Pitch perception depends on acoustic intensity of stimulus (Sound and Hearing - S.S. Stevens).
6. Voices were often double tracked.
7. Preamplifiers were made of vacuum electron tubes which have unique overload characteristics and extreme linearity at small signals.
8. Engineers were thinking flat frequency response from singer's vocal chords to listener's brain. Not just from microphine to loudspeaker. They were using passive EQs like the Pultec for this purpose that contain inductors, (coils wound on magnetic ring cores). The material that must had been used is moly permalloy (moly from Molybdenium to get the right amplification factor or quality factor or Q.
9. The signal path was minimal containing a few electron tubes and impedance matching was done with (magnetic material again) signal transformers which have unique overload characteristics.
10. Analogue recorded magnetic tape was used which has unique overload saturation properties.
So we come to 2017 and all those gradual (like nature's non linearity) saturation properties help fit something so tremendous to something so small as is the tiny speaker of our smart phone when our brain enjoys listening to Aquarious - The 5th dimension, You've lost that loving feeling - The Righteous Brothers, or California Dreaming - The Mamas and the Papas on YouTube.
References:
http://normanschmidt.net/scores/bachjs-general_bass_rules.pdf
Sound Picture Recording and Reproducing Characteristics - Loye, Morgan - Journal of the Motion Picture Sound Engineers
Tubes vs Transistors, is there an audible difference? - Russell O. Hamm - JAES
http://vintagewindings.com/products/TransDesign1.html
No comments:
Post a Comment