This is yet another cautionary true story from the naked city on a theme that I have written about many times in the past.

Yesterday I mastered an acoustic music album for a fine instrumental artist who tried to do it right the first time. He went to a recording studio to get it done (I think it was a "project studio" because they used Cubase), and then went to one of the best-known mastering houses (lots of gold records on the walls) to get it mastered.

The artist was dismayed. The master which came from from this top-notch mastering house was (in the artist's own words) "to my ear, the tone seems "cold" and somehow less compelling than what is available even on the mix-studio ref. In some cases there seems to be a loss of "presence". It is not clear if the problem stems from the method of transfer, or from the method of dithering."

As you can see, this artist has educated himself on the vagaries of digital. He even asked the mix house to supply 24-bit AIFF files on CD ROM from Cubase. On a consulting basis first, I listened to the mix reference CD and compared it to the master. I agreed that the master was grainy and unresolved---even the original mix reference CD sounded clearer and more real. Some bad digital processing or dithering or both had been done in the mastering.

Ironically, very little was done in the mastering, according to the artist, who attended the session, no limiting, no compression, simply EQ (the artist thinks a 1 dB high shelf at 10K, which in most cases he decided he didn't like) and (I think) UV-22 dither. I am not sure if it was digital or analog EQ. Clearly this is a purist project done by an artist with good ears and by the way, the mastering engineer involved has a good reputation with acoustic music.

So, I began to remaster his project. I put up two of the songs on the 24 bit AIFF files. The first thing I discovered is that all 8 bottom bits of the 24 bit source files are ZEROs! Very simple to see if you have a bitscope (lesson number one). So, that means that the original mix house truncated the Cubase mix output somehow when making the AIFF files. That's loss number one which can never be restored without a remix.

I applied very simple digital eq (1/2 dB boost at 20 kHz Q 1.0), some of my "special sauce" processing and POW-R 3 type dither. And the sound is more open, livelier, even clearer, yet still as warm as the original could be considering the truncation. Did I do anything special or different than the original mastering house? Perhaps. But the points to ponder are this:

1-Why did the original mastering house not note and alert the artist that his source mix files were really 16 bits masquerading as 24?

2-Why did the original mastering house not ***hear*** that something was wrong with their processing such that the master sounded worse than the original, even with minimalist processing?

If the shoe ever falls on the other foot and you receive one of MY masters in this condition, I WANT YOU TO CALL ME and tell me about it. Because I would want to avoid it in the future.

Even if you do not know me personally, don't hesitate to call. I accept constructive criticism (usually :-), and I promise I will listen to you. I'd rather be warned than ignorant. Because digital audio IS rocket science (lessons number two through 13). Anyone can get hit with the dreaded "digital bug". As you can see from this precautionary tale, it happens far more often than anyone would like to believe!

Why didn't I call up the first mastering engineer and let him know about his problem?

Because I do not know him well, and I think you do have to know in advance how a

particular engineer might receive this kind of news, hopefully with a positive attitude. But I do hope this cautionary tale makes it his way and that he will check all of his equipment and all software revisions for harmonic distortion (which should be done regularly) and hopefully find his problem.

Bob Katz