Generally analog mastering is a bit more expensive, as, beside a calibrated room, mastering monitors and master grade cables and converters, it uses very expensive analog hardware units specialized for mastering. Their precision, coloration, harmonic saturation in some cases give the song a beautiful shine, make it stand out of the crowd. Generally, in an analog mastering studio the first processes are done digital, like some mix correction and some unpleasant resonance elimination, editing, de-essing or removal of harshness, then the signal is sent out and passes through high-grade mastering equalizers, compressor, harmonic generators. The mastering engineer has the experience to understand what the song needs in order to both enhance it and prepare it for the commercial purposes. The analog hardware units are clean or have some gentle coloration and the master engineers with experience know where and how to use these high-end mastering processors units.
Digital mastering is possible, there are high quality plugins, most of them are simulations of the famous analog hardware units; however, there is a very clear difference between the hardware and their counterpart digital simulation plugins. We tested these plugins doing the master in analog, then use these plugins with the same settings, and the results were very clear: there is a huge difference. That is a reason all the top commercial releases are mastered in analog!
Also, there are some automated
mastering services over internet, like Landr or Aria mastering. They do a decent job, raising the songs level. But as it stands now, all this systems can't judge the flow and feeling of the song, they rather work on automated formulas based on the musical genre. And they also don't do a verification, as the algorithms look mainly at the technical aspect. AI can not grasp emotion, period! For beginners, or for demos, as a cheap way, that can be a solution, but for a song where the musician has the expectation that the mastering brings something valuable to the table I would definitely look at analog mastering. Using an
analog mastering studio over internet is very different than an automated system: a human, the mastering engineer does the work in an acoustically controlled environment with high-end equipment; infact, is the same like being there.
For more info about this subject, and for the technical aspects that mastering deals with, please check the
FAQ section in our website.