There is a lot of information here and elsewhere on the net on this subject. Have you thought about doing a search under what is audio mastering on Google? I came up with 690,000 hits.

Here are just a couple

http://arc.badgerdotcom.co.uk/article256.html

http://www.mrtoads.com/html/audio_mas_whatis.shtml

http://www.desmastering.com/mastering.htm

http://

http://www.amtone.com/audio_mastering.html

To state it simply:

Audio Mastering as done by an experienced Mastering Engineer can make a good song sound GREAT and a so-so song sound good. It is not only about level or compression or equalizing it is about taking a song and polishing it so it sounds good ( and yes one may even say "commercial" ) This "polishing" can use many different pieces of equipment and procedures. A mastering engineer has to have great equipment, a great room and monitors and lots and lots of expererience in order to do all of this.

Mastering is not something you learn from books or from chat rooms on the internet. It takes time and patience and a huge outlay of cash for the equipment and the room.

Mastering is also about taking songs that were done a different times and at different studios and making them all sound good and cohesive so there is a feeling that the album was done in one studio by one engineer.

MTCW

A further thought from a colleague

Mastering is more than a fresh set of impartial ears, although this is certainly one advantage. It's the experience of the ears in mastering, which is different from mixing. The best mix engineers still get all of their work mastered. It's a different discipline, however related. It's the training of the ears, knowing what to look for, knowing how far to go, knowing how it will translate, knowing the monitors, the experience with so many records that have come through, with what works and what doesn't. It's the training, the knowledge that has been passed on by somebody more experienced, learning the aesthetic and technical details that aren't obvious or seem counter-intuitive to the lay person. It's the gear. Its the well designed and implemented monitoring environment, the high definition full range monitors, the knowledge of when and how to dither, what type, what gain, noise shaping or not, which curve. It's having the highest quality processing gear and the cleanest signal path. It's having digital gear that processes at a high enough resolution for the resolution of your project, and gear that doesn't truncate, and offers you dithering options when you need them, and has tried and tested quality algorithms and proper DSP practice. It's quality A/D and D/A and properly maintained and calibrated tape machines. It's understanding PQ codes, ISRC codes, noise reduction, and different master formats that will come in and be delivered. It's having the proper gear to make masters that glass can be cut directly from. It's knowing what glass mastering is in the first place, and why that's not done at the "mastering" houses we are talking about, It's knowing the difference between mastering and pre-mastering. It's knowing when to use analog or digital, how to get to and from digital with the least degradation. It's not getting carried away, it's restraint, but it's not necessarily timid. It's attention to detail, cleaning heads and tails, adjusting fades when necessary, making the album even from track to track, not thinking normalization will do this for you, understanding emphasis, not losing bits of data that are important or passing bits of data that are incorrect, knowing what to do about DC, phase relationships, balance, clicks, pops, dropouts, and how to prepare a proper log for the replication plant.

It's all of this and more. It is NOT simply putting an EQ and a limiter on the mix bus so your CD is loud and bright. If you don't understand the difference, you are sadly missing out on one of the most valuable assets in the completion of your project that you have put your heart and hard work into.

Jay Frigoletto
Mastersuite
Los Angeles

Thank you very much Thomas, your insight was helpful to me. Now I know I will be paying someone else to master any projects I need completed lol. Thanks again

Don't forget divine intervention :D

Indeed, there are moments when something comes out so perfectly, almost by accident, that I feel like divine hands were involved in the final product. :)