Transparency, color, neutral, dark, bright

[crazydoc]

These are terms that are bandied about a lot in audio circles (as are "warm", "tube", "iron" and others.) I have not been able to find much agreement on what they mean. (Maybe it's like trying to describe the color "red" - however, colors can be defined as portions of the electromagnetic spectrum, without being able to see the actual color.)

Dan Richards (Dot) has developed a graph to try to sort some of these out, and it seems a useful initial attempt to do so.
http://www.thelisteningsessions.com/...mic-graph1.jpg

There are several threads here that have attempted to discuss these concepts, with varying success.
http://www.homerecording.com/bbs/sho...d.php?t=140027
http://homerecording.com/bbs/showthread.php?t=108464

I am interested in trying to get a better handle on these concepts, as I've been trying to design a mic that pulls the signal off different portions of the membrane, each with different harmonic content, and then mix/sum the resultant signals to vary the harmonic/sonic content or "color" of the resultant summed signal. This has been a resounding failure so far - not because of the concept but rather because of the terrible signal to noise ratio of available transducers.

In any case, I'd be interested in hearing any opinions as to what the above terms signify to different people.

[acorec]

Originally Posted by crazydoc

These are terms that are bandied about a lot in audio circles (as are "warm", "tube", "iron" and others.) I have not been able to find much agreement on what they mean. (Maybe it's like trying to describe the color "red" - however, colors can be defined as portions of the electromagnetic spectrum, without being able to see the actual color.)

Dan Richards (Dot) has developed a graph to try to sort some of these out, and it seems a useful initial attempt to do so.
http://www.thelisteningsessions.com/...mic-graph1.jpg

There are several threads here that have attempted to discuss these concepts, with varying success.
http://www.homerecording.com/bbs/sho...d.php?t=140027
http://homerecording.com/bbs/showthread.php?t=108464

I am interested in trying to get a better handle on these concepts, as I've been trying to design a mic that pulls the signal off different portions of the membrane, each with different harmonic content, and then mix/sum the resultant signals to vary the harmonic/sonic content or "color" of the resultant summed signal. This has been a resounding failure so far - not because of the concept but rather because of the terrible signal to noise ratio of available transducers.

In any case, I'd be interested in hearing any opinions as to what the above terms signify to different people.

Here is some text lifted from Earthworks mic company on how they test their mics:

"Here at Earthworks we use the well known substitution method on a daily basis to measuremicrophones. The substitution method presumes a microphone with a known response in order tomake the sound source errors virtually disappear. Essentially, the test is performed like this: theknown microphone is placed at a specific location in front of a sound source, the source's frequencyresponse is measured, then "nulled" (i. e. referenced) and corrected for the microphone's frequencyresponse. Then the microphone under test is positioned in place of the reference microphone whereits response can be measured and compared to the reference.This method, however simple it might look, has pitfalls and requires a deep understanding of theprinciples involved. International standard IEC 60268-4 describes the conditions under which thistest must be performed. The first and the most important requirement is that microphones should bemeasured in free field, employing plane waves or spherical waves. This means that a sound sourcemust be small compared to the wavelength at any frequency under test and the microphone testedmust be far away from the source. In a case where either the circumference of the source and/or thatof the microphone exceeds the wavelength, the measuring distance must comply with:r>dr>d2/λwherer is the distance from the source to the measuring point;d is the effective diameter of the sound source...."

Like I said before, there is no "chart" that tells a specific number of "color" or "Brite/dark". This information is *relative* to a measurement mic using the method above. The culmination of the differences in the freq plot from the mic under test and the measurement mic is the total "sound" that the mic under test will have. Thers are only two real parameters in a freq chart and those are 1. EQ and 2. Shelf/rolloff. People can name them whatever they want. The terms "color" and "brite/dark" are soley inventions of these types of newsgroups and audio magazines that want to sell mics. How a mic reacts to a sound source is *indicated* by the freq chart. If the freq chart *indicates* that a certain mic would be best suited for a kick drum, then you would not really want a mic who's freq chart cutoff the low freq's and boosted the high freq's. Dot's chart is an invention of his to show *relationally* by sheer experiment where each mic lies on the audio spectrum.