[Warning: Nerd-speak ahead!]
If you’ve ever heard the term “RIAA equalization”, that’s a standard that was adapted around the mid-1940s, which was developed to try and maintain some kind of standard for vinyl mastering.
I borrowed this bit from a wiki article:
“RIAA equalization is a form of pre-emphasis on recording and de-emphasis on playback. A recording is made with the low frequencies reduced and the high frequencies boosted, and on playback, the opposite occurs. The net result is a flat frequency response, but with attenuation of high-frequency noise such as hiss and clicks that arise from the recording medium.”
What generally has to happen when mastering for vinyl:
To over-simplify it a bit, you basically invert the EQ for the vinyl master, so the signal won’t be over-modulated. If the grooves being cut are over-saturated, then when you play the vinyl back, it can often be too much for the stylus to handle, and that’s when the needle starts jumping out of the grooves. Sometimes, the grooves end up being cut non-uniformly, and they can even bleed right into each other.
A vinyl master would have the lows turned way down, and the highs turned way up, and depending on the tracks, could sound pretty harsh turned way up.
For that reason, an.mp3 would not make for a good master – .wav files are definitely to your advantage. The reason being that the very nature of an .mp3 is an algorithm that somewhat arbitrarily removes certain frequencies, in order to make the file more compacted. Typically, that will end up being high-end frequencies, because the common assumption is that most people can’t hear frequencies in that range – generally, between 15-20kHz. To my ears, that often results in a tinny metallic “whoosh”-ing kind of sound, but people I’ve worked with have told me more than a few times that I fuss over frequencies no one else can hear other than cats or dogs, so who knows? Just putting that out there, at any rate.
Please note that *if* you have audio that has already been mastered specifically *for vinyl*, then you can feel free to ignore everything I just talked about in the last few paragraphs. If your audio has been mastered for CD or streaming, a *minimum* of one to two hours mastering time will be required.
We can talk more about all of this when we connect, but at least this might give you some ideas to think about for your project.