Premastering for Vinyl Recordings What you need to know to prepare your audio for vinyl:
Pre-mastering is the process of getting your audio ready for the vinyl lacquer cutting stage. If your audio is already mastered for vinyl, you will not require pre-mastering services from Microforum. Below is what you need to know to have your audio files vinyl ready...
How you have recorded, mastered and the medium you send it to Microforum all contribute to the final sound. What is required for submitting an acceptable vinyl premaster to Microforum?
Source Audio Files:
24 bit 96kHz WAV or AIFF format file is the vinyl pre-master standard. Other file resolutions are acceptable, down to CD quality audio, 16 bit 44.1kHz
File resolution should be the highest available, but should not be converted up to a higher resolution.
MP3 audio is not a suitable source for vinyl production.
The source audio files should be provided as a single WAV or AIFF format file for each side, with track spacing as it is intended to appear on the record and with an accompanying PQ sheet, indicating track IDs
A Note About High Frequencies:
The lacquer cutting system (the next step in vinyl manufacturing) is capable of putting very high peak levels on the record, but only ideal playback systems in optimal conditions will be able to play the sound back without distortion. Since we need the record to be playable on all types of equipment, it's necessary to limit the High Frequency information. It's recommended to provide a vinyl premaster that already has a balance of high frequency suitable for vinyl production.
A Note About Low Frequencies:
Excessive level in the very low bass can cause the record to skip. Excessive stereo information in the bass appears as vertical movement in the groove, so it's sometimes necessary to remove the stereo component of the music as well as any out of phase information in the very low frequency range. The cutting system is equipped to correct minor issues with the bass however, more severe problems will result in a record that can't be cut or that sounds very different from the source audio files provided. It's recommended to provide a vinyl premaster that already has low frequency level and stereo content that is suitable for vinyl production.
As a general rule, the longer a side is, the quieter the record will be. Our general guideline for maximum side length is 20 minutes for a 12" 33 rpm record and 14 minutes for a 12" 45 rpm record. However, it's the bass content in the music that takes up the physical space on the disc, so it's sometimes possible to have a longer side without compromising the level or audio quality. Not all masters benefit significantly from shorter sides. As well, some styles of music are more ideally suited to a higher playback level, in which case shorter side lengths (15-18 minutes for 12" at 33 rpm, 9-12 minutes for 12" at 45 rpm) are recommended. For 7” record pressing, our general guideline for 3 – 4.5 minutes per side for a 7" 45 rpm record and 5 - 7 minutes per side for a 7" 33 rpm record.
The deeper (louder) and wider the cut (more bass), the more space (therefore time) it consumes on the record.
We cut your record at the maximum level possible within the confines of the vinyl medium. The factors determining the level are a combination of the HF and LF issues explained above, and the running time. The longer side of the record determines the level for all sides, unless otherwise specified.
Reference Acetates or "Dub Plates":
Any time that there is a question about whether or not your record complies with these guidelines, there is the option to cut a reference acetate first. An acetate is a disc that is cut just like the master record and can be played a few times to hear what your records will sound like. It can save the extra time and the expense of additional test pressings if you're unsure. Please contact your Account Manager for details.
What are the best ways to send us your audio master files?
All audio master files can be sent via file transfer service such as Dropbox, Wetransfer, Google Drive etc. Audio files can be emailed to your account manager directly.
Important Information on the Production Queue Sheet:
The PQ sheet tells us everything we need to know in order to cut and press your record correctly.
Start IDs for each song, not just each side, since sometimes it’s hard to tell where one song ends and another starts. Also, they’re handy for checking each song
Write down accurate timings for each song AND total side time including pauses. So much time is wasted by the cutting engineer having to figure out times, and it’s imperative to know before cutting