It seems common knowledge that most forms of physical entertainment media are on the decline. For example, Best Buy recently announced it would no longer sell CDs in its stores. Meanwhile, streaming content is growing by leaps and bounds. But one physical format seems immune to this trend: vinyl LPs. According to Billboard, 2017 was the 12th straight year of growth in vinyl-album sales.
Many cite the ineffable quality of analog audio as one reason that vinyl is bucking an otherwise downward trajectory in physical-media sales. Even so, the performance specs of vinyl are nothing to write home about. The dynamic range and signal-to-noise ratio are typically in the range of 60-80 dB, which might actually be wider than many pop CDs with a heavily compressed dynamic range. But it’s still well below the capabilities of CD audio, not to mention high-res audio.
Also, vinyl LPs are theoretically capable of representing frequencies up to 50 kHz or so, but they are typically limited to no more than 20 kHz. Of course, this is greatly affected by the playback system. According to Pspatial Audio, its measurements of a “first-class deck” (turntable) playing various industry test discs resulted in a frequency response from 40 Hz to 15 kHz (±1 dB) with a dynamic range of 66 dB. (The other results are also quite interesting; check them out here.)
To address these issues, an Austrian company called Rebeat Innovation is working on a way to greatly improve the performance specs of vinyl. Dubbed HD Vinyl, the process starts by converting a high-resolution audio file into a topographic 3D map of the grooves—or, to be more precise, the “anti-grooves,” ridges that are the exact inverse of the grooves in the intended record. Next, a laser etches those ridges into a ceramic plate by removing the material around them, a process called ablation. This creates the stamper that is pressed into vinyl blanks, forming the final LP.
A laser is used to create a ceramic stamper with ridges that precisely mirror the grooves that represent the audio. These ridges are pressed into vinyl blanks to create the final disk. (Courtesy Rebeat Innovations)
This process offers several advantages. First, it’s much simpler and less prone to information loss than the conventional method, in which the stamper is three generations removed from the original master lacquer. According to Rebeat, the lacquer produces a father disk, which then produces a mother disk, which then makes the stamper. With HD Vinyl, the laser-engraved ceramic stamper has no generational loss at all.
Because the laser engraving is so precise, the distance between grooves can be reduced, and the tangential/radial error is eliminated. (According to Rebeat, a lacquer is traditionally cut at a tangential angle, while most turntables read in a radial angle, so the needle is constantly tilting.) The result is 30% more playing time per side.
In addition, the grooves can be wider, resulting in a greater peak amplitude and thus up to 30% higher dynamic range and signal-to-noise ratio than conventional LPs. Another benefit of precision laser engraving is the ability to represent frequencies up to 100 kHz—not that anyone can hear that high!
The dimensions of vinyl-record grooves are tiny, as seen in this photomicrograph. (Courtesy Rebeat Innovations)
When I asked Volker Schmidt, CTO of Rebeat, about the issues of frequency response and dynamic range, he replied, “The HD Vinyl laser process has no physical contact with the master plate, so it does not suffer from limitations such as overheating of the cutting stylus or mass inertia that can cause groove degradation at high frequencies and amplitudes. Hence, there is no need to limit the frequency spectrum or amplitude of the audio in terms of fabrication-related issues.
“These days, it is possible to cut higher frequencies (even with a mechanical stylus) than a poor cartridge can play. However, if you talk about ultrasonic frequencies without specifying if they are on the outer or inner rim of the recorded groove, you may be talking apples and oranges. So, the whole setup—recording as well as playback—must be taken into account. If you want a general-purpose cartridge to play your vinyl records, you traditionally have to limit high frequencies and high amplitudes in order to keep the kinematic groove energy below a certain level. That is what mastering engineers and the RIAA filter curve do.
“For the HD Vinyl, the same physics apply—if the kinematic groove energy gets too high, the needle starts to skip or jump out of the groove. But the laser offers a new way to create a perfectly designed groove that gets closer to the physical limits because it is totally different than mechanical cutting (which is, in effect, the reverse of the playback).”
Rebeat also claims that a ceramic stamper is much harder and more resistant to wear than the traditional nickel stamper, which must be replaced after making 1000 copies or so. Even worse, there’s a significant difference in quality between the first and last pressing of a nickel stamper. A ceramic stamper does not wear out like that, so the 1000th copy is identical to the first. Finally, this process completely avoids the toxic electroplating of conventional vinyl production.
LPs created with the HD Vinyl process are completely compatible with all existing turntables. Rebeat is working on new turntable designs that take maximum advantage of HD Vinyl records—for example, with a stylus that perfectly fits the laser-inscribed groove. However, thanks to the laser-engraving process and new groove design, even conventional spinners will purportedly deliver substantial improvements in fidelity when playing the new disks.
I find it very interesting that analog vinyl records could finally join the high-res audio movement. Of course, some will argue that vinyl is already high resolution—in fact, “infinite” resolution because it’s analog. However, given the limits on frequency response and dynamic range discussed here, I disagree with that position. HD Vinyl could bring analog audio closer to what high-res digital audio has already achieved while preserving the je ne sais quoi of analog for those who prize it so highly.