Quantify stereo width (soundstage) in recordings

[logan_cmd]

I'm an avid "metadata" and metric fan and enjoy tagging my digital music (mainly FLAC) with all sorts of metadata. One process I really enjoy is tagging tracks using Foobar's Dynamic Range Meter (foo_dynamic_range) to tag the DR value to the tracks and to the overall albums. Maybe you have seen these foo_dr.txt files in digital music downloads?

One metric I would like to know of existence is the ability to quantify the soundstage. Since I'm a 2 channel listener I want to hear as wide of a soundstage as possible. As we know different mixes (mastering engineers) do a better or less better of capturing this in the mix. It would seem to me in theory that a metric, similar to dynamic range could exist for soundstage width. This seems like it would be a rather loose metric, as some instruments are panned way out in the mix and depending on what that instrument is than it may have less dynamic impact, for lack of a better word. Thus something like a higher frequency instrument, like a triangle panned way out to the left or right, would not register as high as a kick drum panned out, but this is where it would seem that it would not matter on the "heft" of the instrument. Simply knowing there is content "out there" to the left or right, or both is really what matters, as this is really what presents a nice wide soundscape.
So in theory this would be some type of single value metric that describes in some unit, maybe degrees from center, how far is content exists in this recording. This would be a great metric to be able to compare systems and compare different masterings of the same recordings. Plus it be great to find which recording are simply crammed in the middle and which have a nice open sound stage. I know when I listed to different masterings of the same album that I can litterally hold out my arms and "point" to the sound stage. Some recordings are super wide, almost feeling 90 degrees from center, while other masterings are very narrow, feeling like 20 degrees from center.

Does this metric exist? If so is this a graphical presentation, or is this something that could be ported into a nice plugin into foobar? What might this software be if it does exist, or does anyone know of a existing plugin?

Thanks for reading all these words!

 

[MrBoat]

I'm an avid "metadata" and metric fan and enjoy tagging my digital music (mainly FLAC) with all sorts of metadata. One process I really enjoy is tagging tracks using Foobar's Dynamic Range Meter (foo_dynamic_range) to tag the DR value to the tracks and to the overall albums. Maybe you have seen these foo_dr.txt files in digital music downloads?

One metric I would like to know of existence is the ability to quantify the soundstage. Since I'm a 2 channel listener I want to hear as wide of a soundstage as possible. As we know different mixes (mastering engineers) do a better or less better of capturing this in the mix. It would seem to me in theory that a metric, similar to dynamic range could exist for soundstage width. This seems like it would be a rather loose metric, as some instruments are panned way out in the mix and depending on what that instrument is than it may have less dynamic impact, for lack of a better word. Thus something like a higher frequency instrument, like a triangle panned way out to the left or right, would not register as high as a kick drum panned out, but this is where it would seem that it would not matter on the "heft" of the instrument. Simply knowing there is content "out there" to the left or right, or both is really what matters, as this is really what presents a nice wide soundscape.
So in theory this would be some type of single value metric that describes in some unit, maybe degrees from center, how far is content exists in this recording. This would be a great metric to be able to compare systems and compare different masterings of the same recordings. Plus it be great to find which recording are simply crammed in the middle and which have a nice open sound stage. I know when I listed to different masterings of the same album that I can litterally hold out my arms and "point" to the sound stage. Some recordings are super wide, almost feeling 90 degrees from center, while other masterings are very narrow, feeling like 20 degrees from center.

Does this metric exist? If so is this a graphical presentation, or is this something that could be ported into a nice plugin into foobar? What might this software be if it does exist, or does anyone know of a existing plugin?

Thanks for reading all these words!

I have found that just about any modern, well-known brand of speaker has a sound stage that is not only realistic, but inescapable, in my experience. Especially anything containing a waveguide on the tweeter, regardless how subtle. This is what has hooked me into far out genres that I would not have dreamed of listening to before. It's all the effects that you can reach out and touch. Hooked me on to the percussion sections where they exist. I listen near field. Even with the speakers at arms length, I really have to move off axis to throw off the stereo image.

ETA: I find super desktop 2.1 is much more immersive with regard to bang for the buck, especially for an audience of one. The sofas on either side of me become room treatments, along with the padded carpet under me. For example, on a Patricia Barber cut, someone walks across from one side of the stage to the other, and then back again. It's so realistic you can watch them walk in your mind and exactly where they are at all times.

Another is a tune from one of the Yello albums where an airplane comes from behind you, pans across in front of you and keeps going past until it disappears in the distance.

 

[lovinthehd]

I'll get out my tape measure....

Never heard of such a metric and doubt there ever will be one....and would think it would have to come from those making the recordings...and they'd need some sort of standard or metric in that regard that I don't think exists either. If there was an interest in doing so, they'd have done it already....the wants of audiophiles comparing recordings/speaker setups just don't count for much....

 

[shadyJ]

I'm an avid "metadata" and metric fan and enjoy tagging my digital music (mainly FLAC) with all sorts of metadata. One process I really enjoy is tagging tracks using Foobar's Dynamic Range Meter (foo_dynamic_range) to tag the DR value to the tracks and to the overall albums. Maybe you have seen these foo_dr.txt files in digital music downloads?

One metric I would like to know of existence is the ability to quantify the soundstage. Since I'm a 2 channel listener I want to hear as wide of a soundstage as possible. As we know different mixes (mastering engineers) do a better or less better of capturing this in the mix. It would seem to me in theory that a metric, similar to dynamic range could exist for soundstage width. This seems like it would be a rather loose metric, as some instruments are panned way out in the mix and depending on what that instrument is than it may have less dynamic impact, for lack of a better word. Thus something like a higher frequency instrument, like a triangle panned way out to the left or right, would not register as high as a kick drum panned out, but this is where it would seem that it would not matter on the "heft" of the instrument. Simply knowing there is content "out there" to the left or right, or both is really what matters, as this is really what presents a nice wide soundscape.
So in theory this would be some type of single value metric that describes in some unit, maybe degrees from center, how far is content exists in this recording. This would be a great metric to be able to compare systems and compare different masterings of the same recordings. Plus it be great to find which recording are simply crammed in the middle and which have a nice open sound stage. I know when I listed to different masterings of the same album that I can litterally hold out my arms and "point" to the sound stage. Some recordings are super wide, almost feeling 90 degrees from center, while other masterings are very narrow, feeling like 20 degrees from center.

Does this metric exist? If so is this a graphical presentation, or is this something that could be ported into a nice plugin into foobar? What might this software be if it does exist, or does anyone know of a existing plugin?

Thanks for reading all these words!

The term you are looking for is Apparent Source Width.

 

[fmw]

You should be able to measure it yourself. You will need a sound pressure meter (not terribly expensive) and a test tone. Probably free on the internet. Then it is just a matter of measuring the SPL from different locations. Put the data in a graph and behold.

 

[Bucknekked]

The term you are looking for is Apparent Source Width.

@shadyJ ,@MrBoat

I come to the AH after all these years because I can almost always learn something. Audio has been one of my lifelong hobbies but let's face it, many of the members here have forgotten more than I ever learned on the subject. Today was a good day. I learned something, or rather, re-learned and refreshed.

I thought the OP had a great question about trying to quantify the stereo effect with a metric. I had certainly never heard of one but thought it was an interesting idea. Low and behold @shadyJ comes up with the exact terminology at the drop of a hat. Apparent Source Width. Who knew? I read the article and then wondered why I had never heard of it. I went to my best source of audio nerd stuff, Floyd Toole and even though the terminology of Apparent Source Width isn't used, in Chapter 15 of his book, section 15.3 and onward he discusses the exact idea and the challenges of creating the soundstage in the recording process.

According to Floyd Toole, there isn't a metric because it's so danged hard to create the image in the first place that no one would agree on what the finished product really sounded like. He also makes very specific the argument that true stereo (and 2.1) is so targeted to the listening seat that as soon as you vary from it you will be hearing something quite different. I can prove this is my own little listening room by just moving. @MrBoat and I both have a near field setup. Easy peazy to demonstrate there

What a great topic and idea to think about. @lovinthehd pointed out we don't have a metric because nobody gives a crap what audiophiles think about the sound amongst those who do the heavy lifting of making the recordings. Probably true. They care about the artistic value of the music. Fair enough. I guess we will just have to rough it out here.

 

[MrBoat]

@shadyJ ,@MrBoat

I come to the AH after all these years because I can almost always learn something. Audio has been one of my lifelong hobbies but let's face it, many of the members here have forgotten more than I ever learned on the subject. Today was a good day. I learned something, or rather, re-learned and refreshed.

I thought the OP had a great question about trying to quantify the stereo effect with a metric. I had certainly never heard of one but thought it was an interesting idea. Low and behold @shadyJ comes up with the exact terminology at the drop of a hat. Apparent Source Width. Who knew? I read the article and then wondered why I had never heard of it. I went to my best source of audio nerd stuff, Floyd Toole and even though the terminology of Apparent Source Width isn't used, in Chapter 15 of his book, section 15.3 and onward he discusses the exact idea and the challenges of creating the soundstage in the recording process.

According to Floyd Toole, there isn't a metric because it's so danged hard to create the image in the first place that no one would agree on what the finished product really sounded like. He also makes very specific the argument that true stereo (and 2.1) is so targeted to the listening seat that as soon as you vary from it you will be hearing something quite different. I can prove this is my own little listening room by just moving. @MrBoat and I both have a near field setup. Easy peazy to demonstrate there

What a great topic and idea to think about. @lovinthehd pointed out we don't have a metric because nobody gives a crap what audiophiles think about the sound amongst those who do the heavy lifting of making the recordings. Probably true. They care about the artistic value of the music. Fair enough. I guess we will just have to rough it out here.

Growing up with audio, it never occurred to me to even realize if any real image or soundstage was part of recorded playback. I had seen recording studios and pictures of such and the bands I was into, in studio as well, with live albums being my least favorite, regardless of mic placement during the recording. I don't know how, but imagination used to (and still does for me) fill in all the gaps, based on seeing live shows, and just putting faces to the instruments and making what we wanted of it in our minds. Half the time, the album liner and notes completing the story. Sometimes I can imaginatively see a band member in a studio booth by himself, working on a solo part, while wearing headphones.

Loud playback has always been immersive to me, provided the distortion being acceptably low. The only real consistent part of my listening life I have come to realize in modern times is, that no matter the room, car, or anywhere else, and provided the mid bass/bass is right, 87db is where everything starts to come together for me. In other words, all of my speakers need to be able to perform at that level, with low distortion. This tends to rule out most small bookshelf speakers, which tend to start falling towards higher distortion at those levels. It also occurs to me that I had never been to a quiet live concert. To think that I can emulate the live/realistic experience at 60-70db, would have to involve some kind of hat trick. It just doesn't work. Yet half of the admitted audiophiles I know, listen at low volumes, that don't even match the physical efforts the musicians are inflicting on their instruments.

 

[Bucknekked]

Growing up with audio, it never occurred to me to even realize if any real image or soundstage was part of recorded playback. I had seen recording studios and pictures of such and the bands I was into, in studio as well, with live albums being my least favorite, regardless of mic placement during the recording. I don't know how, but imagination used to (and still does for me) fill in all the gaps, based on seeing live shows, and just putting faces to the instruments and making what we wanted of it in our minds. Half the time, the album liner and notes completing the story. Sometimes I can imaginatively see a band member in a studio booth by himself, working on a solo part, while wearing headphones.

Loud playback has always been immersive to me, provided the distortion being acceptably low. The only real consistent part of my listening life I have come to realize in modern times is, that no matter the room, car, or anywhere else, and provided the mid bass/bass is right, 87db is where everything starts to come together for me. In other words, all of my speakers need to be able to perform at that level, with low distortion. This tends to rule out most small bookshelf speakers, which tend to start falling towards higher distortion at those levels. It also occurs to me that I had never been to a quiet live concert. To think that I can emulate the live/realistic experience at 60-70db, would have to involve some kind of hat trick. It just doesn't work. Yet half of the admitted audiophiles I know, listen at low volumes, that don't even match the physical efforts the musicians are inflicting on their instruments.

I can remember way back in the day when I first heard the stereo "phantom image" pop out in front of me. I will save everyone the tawdry details but for me it was one of those "aha" moments that stays imprinted in my mind.
Prior to that, it was just sound out of the radio and whatever my parents were playing at home. After that, I have been chasing that magic ever since.

There are those in the multi-channel home theater world, and on the AH forum as well, who don't think much of the phantom stereo phenomenon. Why should they? They have 5, 7, 11 and more discrete channels to create an audio affect that is "real" verses a phantom one. I've done the 5.1 systems and they do indeed create a great sound field. But me, I've gone back to 2.1 and I'm riding that horse all the way out for now.

The physics of hearing and audio make it clear that its ALL a phenomenon that occurs inside our heads. The dog on the couch isn't hearing it. The cat on top of the cabinet isn't hearing it. The plants don't hear it either. The only creature that hears any of the magic of stereo, or other engineered sound creations, is us. We might as well enjoy it. It's freakin' magical.

Its why we buy all this stuff and invest in how to make it perform. The magic of the music.

(NOTE: I apologize for using the absolutes of ALL and don't and can't. I assume no cats or dogs were harmed)