Than you all for your participation in this topic.
After reading everyones input I think I have a procedure to try.
Assuming a conservative drop in dynamic range of 10 db from
outer to inner groove, and assuming that i would like to restore that 10 db, I should try using the dbx 3bx expander
initally at 0 setting and then for every half inch of travel inward
advance the expansion contol about .2 between 1.0 and 1.1 on the printed scale of the expander contol pot
This would give me a gradual increase in dynamic range across
the stylus travel.
What do you think......?
Also assumint that both bass and treble have been cut, the same thing should be done also, by giving a 1db boost at every half inch of stylus travel.
what do you think
Thank you all again
oldheathkitphil
After reading everyones input I think I have a procedure to try.
Assuming a conservative drop in dynamic range of 10 db from
outer to inner groove, and assuming that i would like to restore that 10 db, I should try using the dbx 3bx expander
initally at 0 setting and then for every half inch of travel inward
advance the expansion contol about .2 between 1.0 and 1.1 on the printed scale of the expander contol pot
This would give me a gradual increase in dynamic range across
the stylus travel.
What do you think......?
Also assumint that both bass and treble have been cut, the same thing should be done also, by giving a 1db boost at every half inch of stylus travel.
what do you think
Thank you all again
oldheathkitphil
Bass and treble response aren't cut from start to finish, that is what I/we have been trying to tell you. What is reduced is the available dynamic range at the frequency extremes, but this may not be an issue at all depending on the dynamic range of the original material.It's always fun to experiment, but I would recommend instead of doing all of this in the analog domain, get some good software sound tools like soundforge etc which will allow you to do all sorts of post processing on the captured files.
I think you will quickly find that the equalization and dynamic range extension you propose to apply results in some pretty awful sound, but who knows.
Good luck...
Thank you Kevinkr, Oshifis, Dangus and others for your patience.
Hopefully I will be able to try this out this weekend.
I listen primarily to classical music, and notice that on many performances the quality goes down as you get into the innergrooves and unfortunately with classical, most of it ends
with crescendos etc. Its almost as if the record should have been cut backward from the inner to the outer groove, like information is stored on a cd.............
anyway......
My I ask one other thing........
I hope this isn't against the forum rules but I posted an inquiry about the nature of Reprocessing and rechanneling for stereo,
which the major record companies did back in the 60's when
the wanted to bring up to date older performances.
Capital called it duophonic, and reissued a lot of Sinatra albums,
etc, and some of the early beatle albums had it done also.
Rca reissued a lot of Toscanini albums, in fake stereo.
can anyone out there tell me what they were doing: I think it was more than just putting bass on one channel and treble on the other.
Thank you all again
oldheathkitphil
Hopefully I will be able to try this out this weekend.
I listen primarily to classical music, and notice that on many performances the quality goes down as you get into the innergrooves and unfortunately with classical, most of it ends
with crescendos etc. Its almost as if the record should have been cut backward from the inner to the outer groove, like information is stored on a cd.............
anyway......
My I ask one other thing........
I hope this isn't against the forum rules but I posted an inquiry about the nature of Reprocessing and rechanneling for stereo,
which the major record companies did back in the 60's when
the wanted to bring up to date older performances.
Capital called it duophonic, and reissued a lot of Sinatra albums,
etc, and some of the early beatle albums had it done also.
Rca reissued a lot of Toscanini albums, in fake stereo.
can anyone out there tell me what they were doing: I think it was more than just putting bass on one channel and treble on the other.
Thank you all again
oldheathkitphil
There was some slight delay also applied on duophonic:
http://en.wikipedia.org/wiki/Duophonic
http://en.wikipedia.org/wiki/Duophonic
I was just browsing the forum when I came across this rather interesting thread.
A few points to note:
1. You describe a gradual roll-off of response of the cutting lathe as the groove diameter reduces. OK, fine. But not all lathes are equal.
2. You mention that the cutting engineer (or preferably, the mastering engineer, not necessarily one and the same) may add some dynamic range compression to allow the original taped recording to be cut onto one side of a piece of plastic. This is largely true, and it is also true that compression makes a recording appear 'louder', even if the peak levels are the same. What's changed is the 'average' level. CD mastering engineers are notorious for uping the compression to get as much of the recording as close to 0dB as possible, and with intent - it sounds louder to the buyer. Why do TV advertisers use compression on their audio? To make them stand out.
But, and here's the tricky bit, removing that compression by 'expansion' requires not just a knowledge of the relative levels, but also the time constants, known as 'attack' and 'release'. And if you are talking about multi-band compression, where the spectrum is cut into chunks and eq'ed and compressed differently, this further complicates the process.
As others have suggested, every cut is made differently, depending on length of the source tape, type of material, requests from the producer, the equipment used, how the engineer was feeling on the day (he might have fallen out with the record company and not take as much care as he otherwise might - OK that's an extreme example but you get the idea).
3. Compression, to me at least, sounds far more acceptable in a recording than expansion. One reason for this is that the ear itself gives the perception of compression when dealing with loud noises (a dynamic range of over 100dB in a healthy specimen). Expansion is a bit like running a tape on playback with Dolby engaged, when the original tape was NOT Dolby encoded. Sure, you increase the dynamic range and reduce the noise, but you are left with artifacts including 'pumping' which are at best distracting and at worst, make the playback unlistenable.
4. Don't assume that your vinyl replay system will have a flat response from groove outer to groove inner. Distortion is usually significantly higher at the inner grooves - boosting the top-end will also boost the level of the distortion, as it's mostly higher order harmonic in content.
5. My recommendation? Transfer the audio direct from vinyl to .wav file using a high quality sound card, with as high a bit rate and depth as possible, and get the recording level as close to, but not over, 0dB as possible.
Then try tweaking the 'pure' source file with some of the many software plug-ins that are available today.
Hope there are a few thoughts for you there.
A few points to note:
1. You describe a gradual roll-off of response of the cutting lathe as the groove diameter reduces. OK, fine. But not all lathes are equal.
2. You mention that the cutting engineer (or preferably, the mastering engineer, not necessarily one and the same) may add some dynamic range compression to allow the original taped recording to be cut onto one side of a piece of plastic. This is largely true, and it is also true that compression makes a recording appear 'louder', even if the peak levels are the same. What's changed is the 'average' level. CD mastering engineers are notorious for uping the compression to get as much of the recording as close to 0dB as possible, and with intent - it sounds louder to the buyer. Why do TV advertisers use compression on their audio? To make them stand out.
But, and here's the tricky bit, removing that compression by 'expansion' requires not just a knowledge of the relative levels, but also the time constants, known as 'attack' and 'release'. And if you are talking about multi-band compression, where the spectrum is cut into chunks and eq'ed and compressed differently, this further complicates the process.
As others have suggested, every cut is made differently, depending on length of the source tape, type of material, requests from the producer, the equipment used, how the engineer was feeling on the day (he might have fallen out with the record company and not take as much care as he otherwise might - OK that's an extreme example but you get the idea).
3. Compression, to me at least, sounds far more acceptable in a recording than expansion. One reason for this is that the ear itself gives the perception of compression when dealing with loud noises (a dynamic range of over 100dB in a healthy specimen). Expansion is a bit like running a tape on playback with Dolby engaged, when the original tape was NOT Dolby encoded. Sure, you increase the dynamic range and reduce the noise, but you are left with artifacts including 'pumping' which are at best distracting and at worst, make the playback unlistenable.
4. Don't assume that your vinyl replay system will have a flat response from groove outer to groove inner. Distortion is usually significantly higher at the inner grooves - boosting the top-end will also boost the level of the distortion, as it's mostly higher order harmonic in content.
5. My recommendation? Transfer the audio direct from vinyl to .wav file using a high quality sound card, with as high a bit rate and depth as possible, and get the recording level as close to, but not over, 0dB as possible.
Then try tweaking the 'pure' source file with some of the many software plug-ins that are available today.
Hope there are a few thoughts for you there.
Cool idea Phil,
Something I had not thought about for years. I do remember reading a number of texts and talking to engineers in the 70s and 80s that described just the process you are talking about. It was up to the skill of the cutting engineer to make it all fit, and fit "right." That's were the skill of the true craftsman came in.
The problem is likely to be that each disc was done differently, tho one would imagine there would be a house style at each plant. It's going to be tricky to undo what was done - without more knowledge. It would be nice if you find some old cutting engineers who can enlighten us a bit. Tricks of the Trade.
Good luck and please let us know what you come up with. I understand your desire to do it in the analog domain.
Something I had not thought about for years. I do remember reading a number of texts and talking to engineers in the 70s and 80s that described just the process you are talking about. It was up to the skill of the cutting engineer to make it all fit, and fit "right." That's were the skill of the true craftsman came in.
The problem is likely to be that each disc was done differently, tho one would imagine there would be a house style at each plant. It's going to be tricky to undo what was done - without more knowledge. It would be nice if you find some old cutting engineers who can enlighten us a bit. Tricks of the Trade.
Good luck and please let us know what you come up with. I understand your desire to do it in the analog domain.
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