Dynamic range compression and treble eq when cutting

[ormandylives]

Gentleman;

I hope someone out there can give me some GENERAL PRINCIPLES to follow.

My hobby is transferring old classical lp music to cd.

I have read that the dynamic range handling capability of vinyl changes by about 10 to 15 db from the outer to inner grooves, and therefore bass
compression has to be used in the inner grooves and treble rolloff has to be applied to prevent mistracking.

Is this correct. ???????????????

If it is true, it would seem that one has to be constantly changing the
treble eq and compensate for the compression as the stylus travels from the outer to inner groove.

To this end I purchased a dbx 3 band expander, that was very popular in the 1980's and a 1/3 octave eq.

Is anyone able to tell me at what frequencies rolloff was done, in both bass and treble, and how it changed as the stylus went from the outer to
inner groove.?????????????

Also where and how much dyamic range compression was used and how it changed during stylus travel.

I am looking for just general principles here as I know each transfer was different.

Thank you very much for any comments you may have.

Ormandylives

[blight]

each cut is unique. you cannot reproduce the original.
the medium does not compress the sound.
you probably mean playback distortion, which increases with decreasing groove radius and increasing frequency - an elliptical needle will reduce these distoritions, compared to a spherical one.

[ormandylives]

Thank you blight for responding.

Perhaps something else is going on.

I have a number of recordings of Beethovens 9th symphony by Ormandy.

One new copy is where Columbia chose to put the whole thing onto 1 lp and when you listen to the Choral Ode to Joy the final movement it really sounds awful.

I have a second issue of the same performance in which columbia issued it on 3 sides so that the 18 minute Ode to Joy is devoted to one side by itself and there is at leass 1.5 inches of unused space before the label.

The first copy leaves only about 1/4 inch of unused space before the label

The second copy with Ode to joy by itself is much fuller in sound, the bass stands out and the choir is very clear.

Both copies were bought brand new and played on my turntable a relatively high end vpi turntable with a benz glider moving coil cartridge.

It really sound like more is going on them treble roll off in the inner grooves.

Does anyone have any thoughts.

thank you

ormandylives

[mossboss]

Ormandy
Here is a bit of food for thought Assuming that you have two records with the same music on them as you have described a possibility is as follows:
They have been cut on different lathes at different pitch rates If you look carefully at the one that has the better sound you will see there is a lot more space between the groove in comparison to the one that sounds badly
To pack that much music on one LP one has to go for a lot of density which can only be achieved by cutting at very low levels Anything up to 280 lines per inch As a bit of quick explanation it works something like this The stylus cuts left to right by adding both signals L and R and to move up and down as it "plows" it subtracts from left to right That give it what it needs to do the job
So the higher the levels at which the master or acetate is cut the more movement of the stylus L to R the more space it will take the less time on the LP Further if the cut was done on a cutting lathe with constant pitch such as a Scully the problem will be even more as the cutting guy has to allow space for the loudest passages so the groove does not join in which case he wastes a fair bit of vinyl real estate on the quieter sections as they do not need as much space Never the less he has to do that as he is committed to a constant cutting pitch.There was the Zuma software as well as hardware running the CPM operating system that was hooked up to cutting lathes so as to overcome this by looking ahead as to what was to be cut and it adjusted the speed of the cutting head motor so as to compensate for varying track width.Neumann in they design did it in a different way by storing the next to be cut say 270 degrees of the rotation before hand and adjust the pitch accordingly The data was then dealt with providing variable pitch. In your endeavors may I suggest that you choose the widest "cut" groove if you do have a choice Also keep in mind that the pressing process has a fair bit to do with the resulting quality of a record The stampers are only good for about 800 pressing which is about an 8 hour shift at which point the stamper has to be replaced with another if they are going to press a few thousand(s) they need a constant supply of stampers which are taken of the mother which is taken from the master which is taken from the acetate. So you can see a quite long chain of reproduction steps that will have a detrimental effect on sound quality from the original master. Assuming a run of say 10,000 records the will be at least 1000 stampers required and that cannot be had from one master the job has to be cut at least three times and make enough mothers to produce stampers If you recall Master recordings where quite expensive since they where pressed form the master not from the mother come stamper
Hope this is of some help
Cheers
Chris

[ormandylives]

Thank You Mossboss for replying.

Forgive me as I was away from my computer during the weekend.

If I understand what you are describing, the cutting engineer must cut back on amplitude to get more playing time onto the record.

May I ask, if treble roll off in the inner grooves is also done ?

And is bass compression and / or bass cutting in the inner grooves ?

I know that each record will be different but are there general principles used in using compression with respect to distance from the center ???

Thank you very much

Ormandy and the philadelphia orchestra lives

Ormandylives

[mossboss]

Ok Lets understand something There is no bass recorded on any vinyl record
That is completely stripped off during cutting and it is put back by the power amp that is compliant with the RIAA curve The reason that there is phono pre amps is to do just that put bass back on the sound that is played back if it is recorded on vinyl
There is no point in me elaborating here on it as there is a plethora of information on that curve freely available on the net as well as elsewhere
Suffice to say that Neumann did do a bit of a variation on the standard curve as they decided that the original standard was wrong
Therefore since most cutting lathes where Neumann a lot of amplifier manufacturers did the pseudo Neumann standard rather than the RIAA standard
There is also quite a lot of info on that score as well The standard was certainly improved by the Neumann alterations not that it will be able to be picked up by an untrained ear since the difference was quite small, however significant, so as to reproduce as true as possible the original sound
I am not in a position at this point to answer your other question however I will return with a precise answer on it Somehow I feel that the question is convoluted as it is about three questions in one So please bare with me
Here is a bit of reading for you any way from a very good outfit that it gives you the RIAA standards on cutting for vinyl http://www.aardvarkmastering.com/cutspec.htm
Cheers
Chris

[emorritt]

I'm assuming you have a 'Columbia Masterworks' recording - yes these were in my opinion of questionable quality and didn't deserve the moniker 'Masterworks'... The grooving was reduced to nearly 300 lines per inch or more, which means the level was cut way low as well. Yes, the RIAA encoding does put *some* bass in the groove, but in addition it's translated to mono swings which at that cutting pitch doesn't leave much room for bass at all. My particular bass box has settings at 30, 70, 250, 350 and 700 hz which means that below whatever frequency selected everything is mono. What Columbia probably did was cut out most of the bass in pre-eq, then sum what was left at a very low level. My experience with Columbia's classical discs is that they require a LOT of end-user EQ tweeking to sound anywhere near good. I have a recording of Mozart's Figaro (I think from the 60's) that is so mid-rangey when the orchestra is full, it hurts to listen to it. Everybody wanted entire works on one convenient record and this was their answer... yeechh!

Another poster was also correct about degradation in the metalwork stages. In the old Victor plant there was a story about Stokowski going down to the processing plant and forcibly stopping workers from buffing the metal parts - claiming that they were buffing the high frequencies off the discs. In the Milton Cross film of the Victor plant it shows the buffing in process. How Columbia got usable pressings from such fine-groove lacquers/metalwork is beyond me. I'd much rather change a disk than hear nothing but what was "safe" to cut at that pitch. Not that I'm an advocate of the old 78 'album' classical stuff, but you can only push any recording medium so far.

I love the PDQ Bach joke about a 'lucky contest winner' receiving the complete works of Vivaldi "recorded on convenient 45 RPM discs which will be sent out one a week with the compliments of station WOOF, over a period of the next 35 years..."

[ormandylives]

Thank you mossboss and emorritt for your replies

I think I am beginning to understand what is really going on.

I listen 95% of the time to classical music and usually the piece will end in a great crescendo, and most of the time it sounds compressed compared to any crescendo at the outer grooves

May I ask if the cutting engineer made an initial setting for bass and did not change it as the record was cut............or would he change it as the cutting got to the inner groove area??????????????

If he changed it......what would he usually do ??????????

Would one of the changes have resulted in lowering the dynamic range in the inner groove area ????????????

Thank you both

Ormandylives

[emorritt]

Different record companies and engineers had different ideas about equalization and while there were some 'standards', what actually got cut and released to the public varied on different labels. The "compressed" sound you're describing is probably more attributable to signal adjustments set for the entire side and not variations during cutting. Before 'hot stylus' recording was available, there would be adjustments in the mid and high frequency response as the cutter moved toward the center of the disc, but hot stylus eliminated the need for groove velocity compensation. If I recall correctly, hot stylus methods came about in the early 1950's and by 1953-54 commercial recordings were all mastered using a hot stylus setup. My guess is that classical sides were 'designed' (for lack of a better word) for optimum play time and then EQ'd to fit the parameters of groove pitch, dynamics, and length of the piece. Scully and Neumann lathes had attachments that sampled the signal coming from the tape machine 1-3 seconds ahead of the playback head attached to the recording electronics, and controlled the cutting pitch and groove depth accordingly in congruence with the dynamics of the upcoming program material. This optimized the run time for such records. I have a set of Scully's pitch/depth controllers but I don't use them; at least not at the moment. Most of what I cut is for dance club or jukebox use and a constant pitch can be set that will comfortably record the material requested at a given level.

[ormandylives]

Thank you emorritt,

That tells me what I have wanted to know..........that pretty much the lathe was set up with predetermined eq and dynamics and there was no further adjustment needed as the cutter reached the inner groove area.

What had prompted this question is that in the transfer of my old classical lp collection from the 50's and 60's ( mostly Columbia masterworks ) to cd, I was concerned with if I could just once set the 1/3 octave eq and the dbx 3 band expander for a "light" 10 db expansion and not have to readjust as the playback stylus got into the inner groove area.

Thank you again !

Eugene Ormandy and the Philadelphia Orchestra LIVES !!!!!!!

orrmandylives

[mossboss]

Well that is great that you did get the answer you where looking for
I suppose that is the difference between musicians come performers and engineers They don't quite speak the same language do they? even though they are in essence in the same game No offense is meant by the way It is just that sometimes the technical aspects are completely missed by the artist just as much as the artistic side is missed by the engineers
By the way Eugene you may as well do a search on the "Loudness Wars" on the net regarding recording levels relating to CD's It is quite an interesting read There has been some great debate on the subject as well, the Jury is still out as you can imagine
The most interesting aspect of producing vinyl at the present as we do is the fact that most people expect a level of sound quality that rarely or never existed in the past when the medium was either vinyl or tape the interesting thing is that they do get it by comparison to days past
You have a perfect example of very poor quality pressings with your Columbia collection
The high quality is certainly demanded from audiophiles who run some very fancy gear like $3-5 K turntables as well as a few $K of amplifiers and pre-amps, records pressed to day are far better than the past
Quite a few of the records in my collection from days gone by are far sort of what can be had to day from just about any pressing plant in the world
That is due to the fact that most vinyl pressing today is for very short runs where one stamper is used
This is made from the "master" in days gone it was never used for pressing it was stored away after they took a "mother" of it, if it was ever used it was what they use to call a "master recording"
Any way that is it from me on this
All is well that ends well and I sincerely hope that orchestra keeps on living
We will keep on doing the vinyl job until who knows!!!!!
Cheers
Chris