Online mastering studios have been around for a number of years now and many musicians maybe be attracted to the lower prices. There is no doubt that saving some money is on a lot of peoples minds these days. This is understandable, however the online mastering services you can find on the internet are wide and varied along with the pricing that you can find. As an operator of a professional online mastering studio myself I find it quite alarming when looking at the websites of some people offering online mastering services. It is very obvious to a mastering professional what studios seem ill equipped or lacking in experience and skill that mastering requires. As such I thought it would be a good idea to list some of the things to look out for when choosing mastering. Firstly I will clarify what mastering is. Mastering is preparing a body of music works for final release medium. This involves fades, spacing, tonal sonic tweaks, tweaks to the dynamic range of the material, entering sub code data such as ISRC codes and UPC/EAN codes and quality control. (click, glitch removal etc) A master format might be a CD-R pre master disk or a DDP file or .wav and MP3 files.
One of the most alarming things I see on some online mastering websites is the lack of mastering grade reference loudspeakers. So many of these so called mastering studios are using loudspeakers that are no better than those owned by the clients seeking the service. Mastering involves eq work, this will ensure the music will translate across sound reproduction systems large and small. With a set of bookshelf speakers there is no way to judge the scale of music as it might sound upon playback on large format speakers such as club PA systems. Low frequency sonic problems are also easily missed on small loudspeakers. Speakers suitable for mastering need to have a close to flat frequency response, high power handling capability (so transients are not softened or distorted), be full frequency range from 25Hz - 20,000Hz and be capable of presenting an accurate stereo image. Every single decision a mastering engineer makes on tone, stereo image, dynamic compression will be directly effected by the loudspeakers he has chosen. As such small bookshelf type loudspeakers simply do not qualify as mastering grade. To improve and correct issues with music you need to be able to hear them.
The same applies to acoustic treatment, in order to linearize the low frequency response of a typical 4 walled room you need vast quantities of RockWool/Owens Corning insulation materials. These large bass traps will absorb much of the bass energy and impede it from traveling back into the room and the engineers monitoring position. This means there are fewer standing waves in the room and any eq work on the low end of any music will be accurate. Without sufficient and effective bass trapping the low frequency response of a room can vary by up to 25dB between 20Hz-300Hz.
When choosing online mastering studios I would consider to oneself why certain websites are graphics and text based only, why do they not show any photos of their loudspeakers, analogue hardware, acoustic treatment ? I will leave that for you to ponder. Personally I think it is rather odd that a professional mastering engineer would not be proud to show off his wares to potential clients. I also suggest looking at the engineers background and recent clients which will give you an idea of the skill level the engineer operates at.
The price for online mastering can vary widely as well, of course there will be a budget available for the job at hand and these days you can find online mastering from £10.00 - £110.00 per track. In many instances online mastering studios may offer a free mastering preview. This is a great opportunity to hear what quality is on offer for the purposes of comparison without obligation. It really does put a considerable power in the hands of the client to choose the right mastering service for his or her music.