It was compression, then expansion to reduce noise. There was a device that controlled both ends of the process. No frequencies were eliminated and the process was used to expand dynamic range. Lessor one sided Dolby systems were not as good but master tape with Dolby pro encoding were known as the best possible tape playback (10 inch reel to reel, not cassette).
Dolby vs. pre-Dolby
This is a topic I’ve brought up a few times before but with little response. Hopefully this time someone will be interested. Many Agoners have made reference to the fact that records from the ‘50’s sound the best.
My contention is that with the advent of Dolby (created for the purpose of reducing tape hiss) in the early ‘60’s, a very audible degradation of sound ensued. This can be heard not only on LP’s but also on CDs created from analog tapes. There is an openness and seemingly unlimited space on the pre-Dolby discs that I feel is lacking on Dolbyized discs. It can be heard most markedly on orchestral recordings. Without Dolby, the full orchestra surrounds you and still there Is a great sense of detail. With Dolby a lot of the wonderful ambience is lost.
Dolby’s cutting off of the highest frequencies, although allegedly electronically replaced, eviscerates the sound and deprives us of the full picture.
Has anyone else heard this phenomenon?
My contention is that with the advent of Dolby (created for the purpose of reducing tape hiss) in the early ‘60’s, a very audible degradation of sound ensued. This can be heard not only on LP’s but also on CDs created from analog tapes. There is an openness and seemingly unlimited space on the pre-Dolby discs that I feel is lacking on Dolbyized discs. It can be heard most markedly on orchestral recordings. Without Dolby, the full orchestra surrounds you and still there Is a great sense of detail. With Dolby a lot of the wonderful ambience is lost.
Dolby’s cutting off of the highest frequencies, although allegedly electronically replaced, eviscerates the sound and deprives us of the full picture.
Has anyone else heard this phenomenon?
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- 14 posts total
I remember that Dolby C on my cassette deck worked much better than Dolby B. The biggest difference, extension wise, was HX-Pro (servo on the bias). There was also less effective Phillips thing called Dynamic Noise Limiter (DNL), frequency/level playback only noise filter, but never got popular in spite of free license. CD players also have ability to reduce noise by emphasis/de-emphasis (similar to Dolby), but it reduces CDP noise only. Each CD has bit/flag that turns de-emphasis on. It doesn’t make sense now for digital recordings, but might be still in use (emphasis applied during analog recording). |
IMO it's not a dolby fault It's loudness of orchestras https://www.nytimes.com/2020/04/17/arts/music/classical-music-loudness.html If musicians pushing hard in order to squeeze more sound from instruments record engineer won't get details with any technique. |
The time period you are talking about is also when transistor equipment replace tube microphones, recording consoles and tape recorders. As someone mentioned above, multi-tracking was also introduce at this time. To filter out the impact of Dolby NR in the recording process you would have to research when and whether it was used by specific labels and studios. |
- 14 posts total