Voelund: 'Comfort Lives In Belief' - Olli H

[Pedaling Prince]

I remember reading that [in analog recording] in order to compete with the noise floor, they recorded as loud as they could without clipping in the 60s and 70s, and the closer the needle gets to 0, the more smearing you get...

Not so much as loud as they could without "clipping" per se since, with analog equipment, pushing the level that hard would cause an unacceptable level of distortion, and you'd bury the needle on the VU meters.

Actually, recording level meters weren't calibrated the same way in the analog era as they are now. Digital meters are "peak" meters, meaning the measure exact sound level at all times, and they define "0 dB" as the absolute maximum level. It's a "hard limit," that is to say it is physically impossible to exceed it.

Analog levels, OTOH, were generally measured using VU meters, those physical needles that swept across an arc of dB measurements from -20 dB to +3 dB (+6 dB on some meters). In this case, 0 dB was a reference level of specific electrical strength but not a hard limit; it was possible to go beyond it without clipping the signal, hence the reason the scale goes beyond 0. VU meters, unlike peak meters, measure only overall average volume at any given point; brief peaks or drops in the sound can't be measured because the needle, being a physical mechanical device, can't move fast enough to measure them. So, to prevent clipping, 0 dB on a VU meter is actually about 20 dB below the equipment's absolute maximum signal strength; that way, brief peaks have lots of headroom to kick around in so they won't get cut off. The idea with a VU meter was to get the overall average level of your recording to ride the needle between about -6 and 0 dB with only occasional peaks into the red zone above 0 dB; this was designed to give you a good, solid level above the noise floor without clipping the signal.

This method of measuring recording level was mostly meant to compensate for the limitations of VU meter technology since the meter, by its very nature, was not a precise measurement. However, the VU meter's unique properties do make it useful in modern recording as well. Peak meters measure absolute volume from instant to instant but not overall average volume; in other words, they don't give a good idea how loud a recording will sound to the ear since we (humans, that is ) perceive loudness based on overall average level, not the brief peaks in level. So a VU meter can actually show you how loud a recording will sound to the ear. For example, if you take most of my recordings and run them through a properly calibrated VU meter you'll probably see them only peak into the red on a small handful of occasions, but put something like Metallica's Death Magnetic through the same meter and it'll likely move very little, staying in the red zone a vast majority of the time.

In that sense, getting the best level with digital meters is a lot simpler. In your final recording, just boost the overall volume until the loudest sound hits, but does not exceed, 0 dBFS. Voila: perfect level. With VU meters, though, that kind of precision was impossible so the best overall level was much more a matter of judgment in the analog era than it is today.