Thursday, May 5, 2011
Masterdisk - inside mastering vinyl and cutting records
If you haven't been following Scott Hull's insanely informative blog about all aspects of vinyl records...and I mean everything from cartridges down to the groove itself...go deeper down the rabbit hole with his 13 part blog post over at the Masterdisk blog.
I read Masterdisk was going to be having a hands on vinyl class/event at their offices in midtown and I signed up figuring I should learn a little about mastering for when I start pressing my own singles at the very least decide if it was necessary to the process, but I had no idea we were going to actually get into the lathe cutting room, and watch the cutting process.
I knew mastering was an intermediate step between the recording process and finally getting it onto vinyl, but what do they actually do to the source recording?
Randy Merrill described Mastering as putting together a consistent package together, EQ-ing and compressing the sound to give it a greater depth and we listened to a bunch of examples on ridiculously impressive neighbor terrorizing speakers. He deals with everything from determining the space between tracks, to making everything flow as an entire piece, and the process is different for a vinyl master versus cd, of course. The expectation is CD's most likely will be looking for a hotter, louder mix but those same compressions and EQ are going to be different for vinyl. Randy said it's usually a more relaxed, more natural level when thinking about vinyl, but that he needs to watch dynamic high frequency information like cymbals or vocal "esses", which turns into an even more interesting problem once you physically get into cutting into a lacquer master. On the other end, low frequency stereo is hard for the lathe to reproduce (and I wonder if your ear can even distinguish stereo bass), so normally lower end frequencies are mastered to a mono signal.
He really got into the details of the process which I completely appreciated, I'm not that familiar with the specific gear, but as an overall concept to enhance a listening experience seeing what's possible with mastering is pretty incredible.
But this is just the first step in the vinyl process, when it ends up at the lathe technician, he's got an entirely different set of problems to deal with.
That's when we got to where the magic of cutting actually happens, the mastered tracks are sent as a single file 'side' to the lathe tech, who has to contend with grooves per inch, cutting depth, spacing and those challenging "esses".
This cutting machine was state of the art in 1982, it's one of the rare models to actually contain a 4 bit 'computer' which helps control a variable speed screw, allowing for adjustment on the fly of the space between grooves. This is a huge advantage if the entire side is longer than from 18-20 minutes, you're going to seriously have to find a place to start jamming grooves closer together, but what really started to get interesting is when he started demonstrating the physical difference between a cymbal crash for example on the outside of a disk, which could travel as much as say 4 inches, versus that same cymbal crash on the last track, close to the inside ring might only have an inch of groove. Under a microscope we got a chance to see that massive wavy cut the high frequencies created. Not only do the grooves have to allow space between for reproducing that dynamic, but the cutting head itself has to be heated to a much higher temperature to accurately cut into the hard lacquer, as opposed to a bass note which can travel the length of an entire revolution. You start to see where there's a low tolerance for any one step in the process.
It's also amazing to start to look at music in this time based spiral, the entire thing from one groove to the next is traveling at a different speed than it's neighbor. It's also why bands actually had to consider not having high frequency heavy tracks when finishing out a side, they would go for the ballad, or the slow track. Back in those days of only records, musicians would come down the hall and pick up a reference lacquer like this, to listen at home. They also told us once these completely 'cure' they really isn't going to degrade like I previously thought, they can be reliably played like any other vinyl into eternity.
If you're going to go on and press thousands of these, at this point the disk would be shipped to the pressing plant and sprayed with a thin coat of silver and electroplated with nickel to come up with the metal stamper. At that point you could even make negatives of this master for multiple stampers and send them out to other plants, etc. All these different pressing plants are actually included in the matrix numbers of vinyl, and the seriously hardcore could tell you if that pressing was a good year for that plant, or how many generations out the stampers were.
The key to a good record starts with the band and a good source recording, but the mastering process is as important as any one of these steps int he chain, these guys know the technical side of physically committing sound to vinyl. It doesn't matter if it's a quiet folk recording or blown out, in the red garage punk, if you go that far to press it, take the extra step to put it down for the rest of history right. It's a highly esoteric process that takes people with an insanely specialized area of expertese to perform, I have a huge respect for these guys making the magic happen at the end of the day.
The real surprise is that Scott and the rest of the guys at masterdisk took time after their work day to illuminate the process for a bunch of vinyl lovers.... you go home and look at the rows of vinyl in a completely new way. From beginning to end, there's an amazing amount of people involved in the process, from the band down to the guys operating the hydraulic press, or a guy sitting at his kitchen table gluing together sleeves, and hand numbering 7 inch vinyl.
Not to brag but this is why I love NY, to have an opportunity to visit a place like this, and see the mystery firsthand....throwing back the curtain made people who love vinyl already, now look at these discs with more reverence.
I would come every Sunday and it would never get old.
Go follow the masterdisk blog and if they offer this again, go down there and check out how that record makes it to the turntable, or seriously consider contact them if you're involved in pressing records.