Preparing Digital Masters for Vinyl
It is commonly unknown amongst bands and even some record labels that music mastered for CD is often not suitable for creating a vinyl master. In this blog I will attempt to outline some of the processes involved with vinyl mastering and discuss the differences in the formats. Hopefully it will give a little insight to musicians who are having their albums released on vinyl. Vinyl production has been on a steady increase over the last 5 years, and more and more albums I work with are being released on vinyl as well as CD and other digital formats.
Vinyl masters compared to CD masters
Due to the difference in format limitations and how a vinyl master is created, it can often be important to prepare the masters with different audio processing to a CD master and sometimes even a different track order. With vinyl you have to consider length of sides, loudness of the material, and how the frequencies in the master will translate to the vinyl format. For example, an excessively loud digital master, which is often the norm nowadays won’t translate well to vinyl – it will most likely sound flat and distorted.
When digital masters are prepared for vinyl, it is often done without downsampling to CD quality (44.1kHz/16bit) as the vinyl master can be cut from high-fidelity files at most pressing plants and vinyl cutting studios. So if your project was recorded and mixed at 96kHz/24Bit then it can be mastered at the same rate and the vinyl cut from this without any need to downsample.
Vinyl Production: format, speed, length and suggestions for compiling
The most common choices are 7” 45 rpm or a 12” 33 rpm, but 10” is also often available, and the speed they run at can be interchanged. It is generally advisable to stick within the guidelines of the pressing plant regarding the maximum length of each side. The general rule of thumb is the longer the side, the lower the volume will be. For this reason, it is also important to try to balance the length of each side of the vinyl because the overall loudness will be determined by the longest side. Guidelines exist because longer sides will lower volume, clarity and fidelity. A 12” 33 rpm vinyl sounds best at around 15 minutes and due to degradation in quality it is advisable not to exceed 22 minutes. A 7” 45rpm vinyl sounds best around 3 to 4 minutes and degrades past the 5 to 6 minute length.
Next decide how you will compile your tracks onto vinyl. Consider the lengths of the songs, and put the loudest, brighter tracks at or near to the start. The grooves cut closer to the centre are narrower and lose some of the high end and brightness. So it is better to put the softer, quieter tracks at the end of the sides so that any loss in brightness is less apparent.
Preparation of the vinyl masters and compiling the LP/EP/single
The next step is to prepare the mixes for vinyl. This involves audio mastering of the mixes for the vinyl format. In addition to standard audio mastering techniques for CD, common but variable processes for preparing for vinyl are as follows: Shelving the really low sub frequencies below 15-25Hz, mono-ing the bass frequencies (frequency varies depending on source material and width of stereo image in the low frequencies) checking phase alignment of low-mid and low frequencies. Pronounced sibilance is also a problem for the vinyl format, so de-essing during mixing and mastering can be required as excessive transients in these frequency areas will sound more exaggerated and can cause distortion on playback. A loud master with excessive compression or limiting is not recommended for vinyl. The cutting engineer will decide how loud the record can be cut. A louder digital master does not translate into a loud vinyl master.
It is best to compile the album exactly as you want it to appear on the vinyl, as vinyl masters are cut in real time, and cannot be undone. So you can compile the whole side as one file, with the correct gaps, fades or crossfades, already implemented on the digital master. Also be sure to give information about the titles, order and timings of the tracks.
Pressing plants: What methods they use
Now that the audio masters are ready, they will be sent to the vinyl mastering studio or pressing plant where they will cut the vinyl master. The most common methods are DMM (direct metal mastering) or cutting an acetate lacquer. A lacquer is produced by cutting onto a lacquer coated aluminium disc, and DMM cuts straight into a copper disc. There are some rather stark differences between the two methods and whilst DMM appears to perform the best from a technical point of view, many vinyl mastering engineers still prefer to work with lacquers. With DMM the information is better preserved due to the rigidity of the medium, whereas with a lacquer some high frequency loss can happen with time (hence why it is advisable to put the lacquer straight into a fridge until it is time to send it to the pressing plant). DMM also has an improved stereo image due to improved transient response, a more linear phase response and is less prone to groove echo from adjacent grooves. They can also be made longer with regards to playing time. However, in the opinion of some engineers, DMM is more difficult to control precisely when cutting. The sound of vinyl when pressed from an acetate lacquer is generally perceived as warmer, whereas DMM masters can sound more forward in the high frequencies. The difference in the surfaces of the materials and the different cutting angle used gives a different sound characteristic to the music mastered to either format.
Pressing plants: What you need to pay attention to
Now that the vinyl master is created, it should be sent to the pressing plant, where they will press the vinyl. Before the album is pressed, it is very important to get copies of the test pressing from the plant in order to check the sound and quality of the press. Check for excessive surface noise, distortion, clicks and pops. Of course, these artefacts are very difficult to eradicate completely due to the nature of vinyl, but you can compare to other vinyl you own as a guideline. If it is good and you are happy with the sound then you can give the pressing plant the green light to press the album. If not, then you need to discuss your findings with the pressing plant and see what solution they offer. After finding a solution a second test pressing will be required.
When choosing a pressing plant to work with, it is important to make enquiries regarding the reputation of the plant. Going for the cheapest option is not always the best way forward as whilst it might save money in the short term, any problems along the line due to lack of quality control can delay the release of the album or worse, could mean you have to accept an album where the quality is not satisfactory. Vinyl production is expensive and generally limited to smaller runs, so the price per unit is quite high compared to the CD format and it is also reflected in the end price. A poor pressing will not appease fans.
However, if you get it right and you have a good mix, master and press, the sound quality of vinyl can be exceptionally good. While mp3 downloads have become more common and CD sales are generally decreasing, vinyl sales are on the increase.
Thank you for reading this blog, please take the time to view our new online mastering page. We now offer audio mastering as a digital online service from only £30.00 a track. This means you can have your track fully mastered to industry standard no matter what genre of music and better yet we take orders from any country in the world. For all other recording studio services please feel free to browse our site to find out more.
