|To give the final finishing to your recording and to obtain a competitive product, which is able to assert and establish itself on the more than saturated music market, a mastering is by all means necessary. I want to explain in a few sentences, what this last stage is about before the master-CD-R goes to the pressing plant and is duplicated.
Which musician with recording experience doesn't know this: You are listening to the finished production of the mix in the studio through awesome monitors and you're more than happy about the music coming out of the boxes. That's exactly how you imagined the realisation of your own music and on top of that, the competent people on the mixing tables have brought out more than you dreamed of. In the car radio or at the domestic hi-fi system at the latest follows the dreadful awakening: everything sounds a bit mouldy, vaguely and without any bass. How is this possible? Well, the studio monitors, for instance, have another frequency response than normal hi-fi boxes so that on a normal system, everything can sound a lot worse and inanimately than on the expensive monitor boxes. Here, the mastering appears to deliver a final result that sounds good on the old kitchen radio as well as in the car or on a hi-fi system. I want to explain shortly, what exactly is done when mastering and which impact these workflows can have (and will have) on your delivered mix.
First, the frequencies of the material is checked and, if necessary, corrected so far, that general listening habits for the respective style of music are exploited and transcribed. This includes, for instance, the adaptation of the bass- , middle- and treble range. With a too mouldy mix, for example, the vertical spectrum is raised, when a mix has not enough bass depth, the frequency is pushed up to 60 Hz. With this, there are also equalizer and in most cases frequency-dependant compressors und limiter that find application and fit ideally the area to be corrected in sum.
With mastering, it is also possible to add effects such as stereo-expander and, later on, room or reverb on the entire mix. To foreclose it right away: it's not possible to dwell on individual instruments or voices whilst mastering to use these different effects or gadgetry, since it is a finished mixdown, which can only be altered and manipulated in the overall picture. So I might say it right away, that you have to pay attention meticulously when mixing, so that you can export everything as you wish back then! A mastering is only the final finishing and what you mess up whilst mixing cannot be undone or covered up in the end! In case of doubt, it is always better to mix various versions, so that the band as well as the mastering engineer can decide which version is the most suitable for the finalisation.
After the frequency spectrum has been adapted, the songs will get the right volume, so that your CD doesn't sound quieter than the last album of your favourite band. Especially in the last few years, the listening habits have changed, mostly in the louder music-styles, so that everything is mastered bursting loud. In the end, you have to decide whether to opt for the METALLICA-variation (the "Death Magnetic"-album has been mastered really loudly, but one can hear the strong overmodulation in the bass- and vertical range due to the extreme loudness) or if you would rather decide to lower the gauge a little bit, to give the material the necessary air to breath and to maintain the dynamics, which still is very important in the music domain and primary defines it as such.
It is furthermore possible to adapt recordings of various sessions, so that the overall impression is not threatened and everything has a homogenous frequency response and the same volume. Works on compilation-CDs and the editing of historic sound archives to publish as an extra material has already been done several times by me and I have always been awarded praise and approval for it.
Finally, the beginning and the end of the songs will be cut in place, everything will be placed in the right order, the length of the pauses and the passages will be defined and, if necessary, more information such as CD-texts or ISRC-codes will be transferred on the master sound recording medium, before a final control with earphones will ensue and the master-CD-R will be shipped back to the band or the record label.
Another service I offer since a while is the vinyl-mastering. While you can press anything on a digital sound carrier, vinyl has a few physical attributes, you have to know to avoid getting mad in the end about a badly sounding LP. Who knew that, for instance, a bass.area (normally under 300 Hz) can only be converted to vinyl on mono? If you try these frequencies to mix and master, to assign certain gadgetries, the LP of the delivered master might not be pressable or has an extreme overall volume loss as a result. Who did guess, that a too sharp vertical range could affect the finished album so negatively, so that the listening of the disk equals a visit to the dentist?
Therefore, certain norms and rules exist, that should be kept to bring a CD that sounds good, neatly on vinyl. I have already created several vinyl-mastering for some labels and as a vinyl-collector with very good equipment, I attach importance to the quality of a pressing. In some cases, I even reached a better sound on the LPs than the CD-versions, where I prepared the songs too for all the other cases, the results are the same as on compact disc.
To finally emphasise it once more, a mastering is definitely needed it makes no difference if the album is published on CD or vinyl at the end. Even if you are satisfied with your mix, the final mastering opens up a new augmentation of the already heard and brings the sound, where it is most needed, blasts the most and can hold up with other productions when it comes to the volume.