rsaavedra
Headphoneus Supremus
- Joined
- Jan 20, 2002
- Posts
- 5,819
- Likes
- 21
After reading some postings indicating the common confusion between Brightness and Detail in audio, I started thinking about using a video analogy to clarify the distinction. In doing so, I came across some interesting things, so decided to write about it as if thinking aloud.
In audio we usually think of "Brightness" when there is an excessive level of energy in the treble region or higher frequencies of the audio spectrum, e.g. last two octaves, or between 5KHz and 20KHz. Excessive with respect to what? Well, usually with respect to the response in the rest of the audible spectrum, or with respect to the balance between treble, mids, and lows in some neutral reference of choice, e.g. another source, or another amp, another cable, another speaker, whatever component of the same kind you are evaluating.
In video, however, brightness has a very different meaning. True meaning is "white level" as opposed to "color saturation" or "picture level", but let's not get into true subtleties of the video terminology. From the plain couch potato's perspective, and assuming colors are properly saturated and let's say fixed on the TV, if you turn up the "Brightness" of your TV, you expect the whole image on your TV to basically look brighter, e.g. shoot more light everywhere, have more luminous intensity, while keeping the same relative brightness proportion between sections of the image that had different brightness levels. So notice that this notion of video-brightness matches well the notion of audio-volume. In audio, you turn up the volume, and you proportionately increase the output intensity of the signal over the whole frequency spectrum. More or less same thing that happens to the whole color frequency spectrum of the image when you turn up the brightness of your video display. Again putting aside color saturation, let's say assuming that is fixed for simplicity.
So "video-brightness" is more or less the same notion as "audio-loudness".
But what would audio-brightness correspond to in video?
Well, mapping the definition from the audible spectrum to the visible spectrum, it would correspond to higher intensity in the "treble" of the visible spectrum, e.g. in the colors with highest frequencies, which are the blues and violets/purples. So imagine you have a TV whose images looked bluish and purplish, well that would be a change in hue. Let's say images that, strangely enough, wherever they have anything blue or purple, that part stands out as too bright. Then that would be a "Bright" TV, in the "audio sense" of the word brightness: a TV with a "loudness" bias favoring the blues and purples.
Therefore, "audio-brightness" is approximately == "loudness" of blues and purples in video.
Now, what about an analogy between detail in audio and in video?
To talk about "a component's level of detail" is a bit of a misnomer. The details are actually in the signals being played. What components have is detail resolving power. And this notion applies both in the realm of video as well as in audio.
Now, imagine you have a standard NTSC analog TV, let's say 38", you have a specific dot pitch, horiz. and vertical resolution. Given those specs, that TV has a specific detail resolving power. Now, imagine that to the right of that TV you put a high definition digital TV, same size, also 38", and same aspect ratio. But this one will have many more horizontal and vertical lines of resolution than the analog TV, and conversely, smaller dot-pitch. This TV clearly has much more detail resolving power than the former.
But keeping an eye on the goal of this thread, trying to differentiate detail resolving power from the audio notion of "brightness".
If the higher resolution digital TV has the blues and purples matching some neutral levels of reference, but the analog, NTSC TV for some reason had blues and purples stronger and "louder" than normal, then in audio terms that analog TV would be "Brighter" than the digital TV. Yet, remember the digital one has way more detail resolving power. The digital has more "detail", yet the analog one, while having less "detail", can be "brighter" in the audio sense.
So that's the video analogy to clarify the distinction, and the conclusion reached:
"Brightness" and "Detail resolving power" are completely different things.
In audio we usually think of "Brightness" when there is an excessive level of energy in the treble region or higher frequencies of the audio spectrum, e.g. last two octaves, or between 5KHz and 20KHz. Excessive with respect to what? Well, usually with respect to the response in the rest of the audible spectrum, or with respect to the balance between treble, mids, and lows in some neutral reference of choice, e.g. another source, or another amp, another cable, another speaker, whatever component of the same kind you are evaluating.
In video, however, brightness has a very different meaning. True meaning is "white level" as opposed to "color saturation" or "picture level", but let's not get into true subtleties of the video terminology. From the plain couch potato's perspective, and assuming colors are properly saturated and let's say fixed on the TV, if you turn up the "Brightness" of your TV, you expect the whole image on your TV to basically look brighter, e.g. shoot more light everywhere, have more luminous intensity, while keeping the same relative brightness proportion between sections of the image that had different brightness levels. So notice that this notion of video-brightness matches well the notion of audio-volume. In audio, you turn up the volume, and you proportionately increase the output intensity of the signal over the whole frequency spectrum. More or less same thing that happens to the whole color frequency spectrum of the image when you turn up the brightness of your video display. Again putting aside color saturation, let's say assuming that is fixed for simplicity.
So "video-brightness" is more or less the same notion as "audio-loudness".
But what would audio-brightness correspond to in video?
Well, mapping the definition from the audible spectrum to the visible spectrum, it would correspond to higher intensity in the "treble" of the visible spectrum, e.g. in the colors with highest frequencies, which are the blues and violets/purples. So imagine you have a TV whose images looked bluish and purplish, well that would be a change in hue. Let's say images that, strangely enough, wherever they have anything blue or purple, that part stands out as too bright. Then that would be a "Bright" TV, in the "audio sense" of the word brightness: a TV with a "loudness" bias favoring the blues and purples.
Therefore, "audio-brightness" is approximately == "loudness" of blues and purples in video.
Now, what about an analogy between detail in audio and in video?
To talk about "a component's level of detail" is a bit of a misnomer. The details are actually in the signals being played. What components have is detail resolving power. And this notion applies both in the realm of video as well as in audio.
Now, imagine you have a standard NTSC analog TV, let's say 38", you have a specific dot pitch, horiz. and vertical resolution. Given those specs, that TV has a specific detail resolving power. Now, imagine that to the right of that TV you put a high definition digital TV, same size, also 38", and same aspect ratio. But this one will have many more horizontal and vertical lines of resolution than the analog TV, and conversely, smaller dot-pitch. This TV clearly has much more detail resolving power than the former.
But keeping an eye on the goal of this thread, trying to differentiate detail resolving power from the audio notion of "brightness".
If the higher resolution digital TV has the blues and purples matching some neutral levels of reference, but the analog, NTSC TV for some reason had blues and purples stronger and "louder" than normal, then in audio terms that analog TV would be "Brighter" than the digital TV. Yet, remember the digital one has way more detail resolving power. The digital has more "detail", yet the analog one, while having less "detail", can be "brighter" in the audio sense.
So that's the video analogy to clarify the distinction, and the conclusion reached:
"Brightness" and "Detail resolving power" are completely different things.