Mono "Bass" on Vinyl - Definition in Hertz?

V

vinylquestions

Guest
Hey,

What is the definition of "bass" that needs to be mono for vinyl?

I'm seeing different numbers -- below 125 Hz, 150 Hz, 300 Hz, 400 Hz?

Is there any official definition?

Does it depend on what the bass is doing? Traditional "stereo image" versus actively bouncing around? Fairly compressed level versus punchy amplitude changes?

Also for higher frequencies, I'm seeing radically different instructions on this. From nothing should be out-of-phase, to any kind of stereo motion is fine. It this just an issue of being (overly) careful with your lathe, or actually preventing the needle from bouncing out of the groove?

Thanks,
Doug
 

Don Grossinger

Distinguished past mastering moderator
Well-Known Member
Joined
Jan 16, 2002
Location
just north of NYC
Definitely below 90Hz bass should be centered. After that it depends on the track. If things are ping-ponging back & forth, then they may have to be controlled up to 300 Hz.

Do a few test cuts, look at the grooves with different types & amounts os safety processing & determine what is the minimum amount you can use & still have the record be trackable in the real world. Watch the depth of cut meter on the lathe. Obviously, TTs/styli like for the groove to be a fairly stable without large swings in depth. You have to look at the angles the groove is cut at on the disc. If there are right angles being cut, this will be difficult to track. Try getting a "consumer TT/stylus" & try your cuts to see if they work. As you cut louder the groove geometry gets more radical.

Stereo in the mids & highs is not usually a problem.
 
V

vinylquestions

Guest
I'm a musician/producer -- is this something I would be able to work interactively on with a mastering engineer/lathe operator?

Sounds like it might get expensive doing things repeatedly.

Actually now I'm confused about where mastering engineer stops and lathe operator (if I'm using the right term) starts.

Isn't what the mastering engineer outputs supposed to be perfect? :)
 

Don Grossinger

Distinguished past mastering moderator
Well-Known Member
Joined
Jan 16, 2002
Location
just north of NYC
Let me start by saying that almost anything that you want put on vinyl can be made to work. It's just a question of the degree of processing required.

It is seldom that recuts are made based on low frequency stereo image. Unless you are totally out of contol & panning is radically different for L/R channels, a good transfer can be made without serious sonic consiquences.

Here, at least, I am both the mastering engineer & lathe operator. In most studios the mastering engineer also cuts the vinyl him/her self. The exceptions involve places where it is inefficient for a mastering engineer to spend time cutting when they can be in session, and then a dedicated cutting engineer might take another engineer's work & do the production for CD & Vinyl. This is a position I occupied at Masterdisk for Bob Ludwig for a number of years.

As Michael said, limitations of each media must be dealt with. That being said, I know I can cut much of what comes from a CD / digital master without drastic changes. Then it will be "perfect" for vinyl & CD. Usually....
 
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