Friday, May 14, 2010

Not So Fast There, Bubba!

No values without a bit of history…

Back in the early days of broadcast, both 10.0 and 12.5 mW into a 500 ohm line were used as common reference levels that indicated 0VU. In May of 1939, we adopted the current standard of 1mW into a 600 ohm line.

Now you would think that this was driven by the recording industry.

NO No no! It was driven by the telephone company’s standard of limiting the signal level of transmission for a minimum of crosstalk and still provide a satisfactory signal to noise ratio in copper phone lines.

It just so happens that the audio industry then adapted that standard and it has been with us in the recording world ever since.

So our first standard reference level for analog gear is 1mW into a 600 ohm line and is denoted as a dBm. Or more completely as 0VU dBm.

Now I ask you, is your meter set to read dBm?

Next week we will talk about the dBv and others.

Friday, May 7, 2010

Oh That Stupid Audio Engineer

More and more lately, I find myself wanting to discover the true engineer in audio recording. Instead, all I seem to find are knob jockeys. These are people who are into the Hollywood version of the art of engineering. True engineering involves so much more!

Did you know that the word “engineer”, as described by Webster, is “a person who manages a project”? Engineering is the act of managing a project. Based on this definition, I would say that management of a project, which can determine if it is huge success or failure, is a pretty important position.

This being the case, wouldn’t it behoove you to pick a person truly qualified to manage your recording project? With this challenge in mind, I have come up with some questions that will help you determine if you have a qualified “true engineer”.

Ask your prospective engineer what that zero on the VU meter means. I can promise you, you will get all kinds of answers as your prospect scrambles for the right words. You can even give them a hint. It is a one word answer. How can they go wrong? But I bet you will not get that simple, one word answer from them.

So what IS the answer?

Ok… enough of the suspense… Drum roll please!

Ratio! The zero on the VU meter is a ratio of some predefined value and the ratio is equal to that value set. How simple can that be? Your true engineer would not hesitate over this answer and would easily be able to expand upon it… if he is a true engineer.

Now my next question… what is that value? In my next blog I will explain the importance of this understanding and also give some more questions you might want to include in you quest for that professional, the “True Engineer”.