AES Section Meeting Reports

Los Angeles - July 25, 2017

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Do you have a stack of LP (long-playing) records in a box in a disused corner of your house? How about a collection of 45s from a bygone era? Did you know that there is science and art in the creation of those lacquer discs? On July 25, 2017, the AES-LA hosted a vinyl mastering panel moderated by AES-LA Committee member Pete Doell, a mastering engineer in his own right. Bernie Grundman mastered vinyl for some of the greatest albums in modern history, including Carole King's Tapestry, Steely Dan's Aja, Michael Jackson's Thriller, and Prince's Purple Rain. He was joined in the conversation by Pete Lyman, mastering engineer for recent recordings by Chris Stapleton (From a Room, Vol. 1) and Jason Isbell (The Nashville Sound), as well as, Colter Wall, Jade Jackson, All Them Witches, and Rod Melancon. Rounding out the panel , Kevin Gray, the youngest engineer at Artisan Sound Recorders in Hollywood in 1972, worked with America, Paul Anka, The Beach Boys, ELO, and Billy Joel. He's currently the owner and engineer of Cohearant Audio, LLC.
The 1990's vinyl resurgence is well known at this point, and Bernie stated that the vinyl mastering room is constantly busy, and is about 30-40% of his work. Kevin estimated about 85%, mostly in remastering from the major labels. Pete estimates 30-40% of the mastering business is vinyl work; 80-90% of the mastering for a project also includes a vinyl master.
In the earlier years, the vinyl material used for a record used a percentage of lead, which helped to quiet the recording, but current regulations prohibit that composition. When vinyl wasn't mainstream (in the late 1980s & early 1990s), those production runs were small, allowing for higher quality. Kevin opined that the 180 gram pressings are like the "Super Big Gulp of the vinyl world". They are made for mass market consumption. Heavier vinyl has less tendency to warp, but is harder to press without "non-fill", and noisy lead-in grooves.
Concentric grooves were sometimes requested. Monty Python's Matching Tie and Handkerchief is an example, with three parallel grooves. For Disco Volante, the band Mr. Bungle wanted for an interleaved groove, falling between the grooves of the 3rd song "Carry Stress in the Jaw". During the blitz in World War II, horse racetracks in England were closed down. To maintain interest in betting, horserace records were produced with three possible endings on three parallel grooves. The pubs played the records for the patrons, and people bet on the "race".
When asked if anyone manufactures new lathes, Kevin remarked that "there were a lot of them made", and they can be retrofitted with new parts. Pete pointed out that the lathes used to cut the lacquer were really overengineered and built like tanks, especially Scully lathes. New record presses are being made, however.
Kevin stated that when remastering older material, his goal is to match the sound of the original, rather than re-equalizing. Mastering for playback on computers and phones basically isn't done. The discs are made to create two audio channels in one groove, with full frequency response. Cutter head is fairly accurate and small. The larger playback needle can't track all the indentations in a groove, but if it were smaller, it would cut a new track every time. A faster RPM disc lets a playback system reproduce more accurately and sound better, while slower discs put a lot of "data" in a short space, making it harder to track. High frequency energy is harder to track than low frequency energy, hence the creation of the RIAA curve.
Does quality suffer because of a linear cutting system versus the pivot arm in the playback system? The tracking error will be there, the trio said, although the better designed systems skew the geometry to minimize detrimental high frequency loss and distortion. "When the curvature of the groove is greater than the diameter of the playback stylus, you've got distortion and high frequency loss," said Kevin.
Independent artists are keeping 7-inch 45 RPM vinyl alive as well. There are additional challenges for 45s, in that the groove largely starts where the 12" LP stops. The playback geometry is even worse, although the higher RPM helps a bit. For LPs, a 20 minute side or less is preferable. Bernie said it depends somewhat on the type of music. Hip hop really can't go above 17 minutes, while classical can allow longer pieces.
Recordings in the past skimped on bass response because the groove needed to produce it would cause needles to skip. Computers now can cut the grooves better, so the skipping problem is reduced and space on the disc is preserved better. Punchy bass with a high frequency transient leading edge can potentially throw the stylus out of the groove if the groove isn't deep enough.
It was a great evening with three of the best and most experienced vinyl mastering engineers in the business. The AES-LA community wishes to thank them for their time and willingness to share stories.

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