How do you measure sound stage?

[knownothing2]

I’m not sure you realise the assertion you’re making. As audio “soundstage cues” are FR, levels and phase/timing information, if we couldn’t measure any of that there wouldn’t be any measurements of anything and digital audio couldn’t exist.

OK, so there are bench measure proxies for soundstage. One of the claims in this and other threads is that DACs and amplifiers measure so well, there could not be any contribution to in-room performance as it relates to soundstage. Some questions then: 1) how should those measures relate to perceptions of soundstage by listeners specifically? 2) have you experienced any differences in how electronics contribute to how you experience soundstage in your home stereo system(s) when swapping a single piece of electronics ahead of the speakers? 3) if you did, were you able to associate those soundstage differences to specific specifications or bench tests of the equipment in question? or 4) did you experience electronics related differences in how you experienced soundstage in your system that could not be traced back to specifications or bench tests?

kn

 

[bigshot]

Soundstage is an illusion. Auditory clues are used creatively in a mix and the brain perceives them and fills in the gaps to create a dimensional impression in the listener. Whether or not the effect is strong or not depends on the interpretation of the sound that the brain makes. That is a very difficult sort of thing to quantify and measure. And it has nothing to do with the equipment.

All you can do is measure the fidelity of the reproduction of the signal containing the sound cues. That would involve the regular aspects of fidelity… response balance, signal to noise, distortion, dynamics and timing. For human ears, DACs and amps are capable of perfect reproduction of all of these aspects.

With speakers, in addition to the dimensional illusion of soundstage, there is actual physical dimensional information overlaid over the top of the recording by the room. These reflections create response changes and timing shifts that further enhance the illusion of soundstage because they are real dimensional information, not just recorded clues. This aspect is measurable by room correction analyzers that introduce tones into the room and measure them from the listening point using a microphone. The natural acoustics of the room are very important to the realism of soundstage, but that has absolutely nothing to do with the equipment. Measuring the DAC or amp for that would be barking up the wrong tree.

So the DAC, amp and cables are only important to the soundstage in terms of how high a degree of fidelity they have in reproducing the signal created by the sound mixer. That isn’t an issue with modern home audio because these components are generally audibly transparent.

If someone is discerning differences in soundstage, it is almost certainly one of three things… 1) the quality of the dimensional clues created by the sound mixer, 2) the dimensional envelope created by the room, or 3) the subjective processing of the sound by the listener’s brain. In the cases of audiophiles who depend on subjective impressions to judge sound instead of controlled listening tests, it’s probably number three, because they aren’t reducing variables and eliminating the powerful influences of bias and perceptual error. The quality of the soundstage might have more to do with how their underwear cinches up when they sit on the couch or what they had for lunch than anything involving the home audio equipment being used.

 

[71 dB]

We’ve been talking about the effect DACs and amps have on soundstage and how to measure that effect for almost a week. Perhaps you didn’t notice.

I'm not interested of that topic. I have brought topics into this I personally find more interesting.

 

[71 dB]

I tell her not to touch the speakers, but she gets an irresistible urge to vacuum under them!

The surface under the speakers can be marked with adhesive tape to help with resetting the original placement.

 

[bigshot]

Then you don’t need to reply to me, because that’s what I’m discussing!

She would want to clean the tape off too!

 

[Ryokan]

My iems give a song wider or narrower soundstage to varying degrees.

 

[bigshot]

Transducers have more to do with the perception of space than the electronics do.

But true soundstage requires the overlaid envelope of the room acoustics, so headphones and IEMs only produce half of the sound that makes up the soundstage- the spatial cues embedded in the mix.

 

[Ryokan]

And good mic placement.

 

[bigshot]

Microphones are transducers.

 

[Ryokan]

Mic placement when recording to capture a good image of spatiality. Using two or more microphones set at different angels from a vocalist or instrument.

 

[bigshot]

And again, that is the responsibility of the sound engineer. Swapping in another DAC or amp isn't going to affect that at all.

 

[Ryokan]

NEVER SAID IT WAS. Why are you constantly trying to belittle me?

 

[bigshot]

No one is belittling you. The OP believes that DACs and amps affect soundstage. I keep pointing out that soundstage is created by the sound engineer in the mix, and supplemented by the acoustics of the speakers in the room, but that doesn't seem to register. If the thread went in a straight line, it would be clearer, but there are lots of digressions and side issues that keep spinning things off on tangents. So I come back to trying to clarify by focusing back on what the OP is asking about in the hopes that it will eventually be understood and acknowledged.

The term "soundstage" is one of the most misused terms at Head-Fi. I'm just trying to keep on track to avoid it sliding back into the incorrect use.

 

[71 dB]

But true soundstage requires the overlaid envelope of the room acoustics, so headphones and IEMs only produce half of the sound that makes up the soundstage- the spatial cues embedded in the mix.

That's why I try to develop methods to come up with spatiality embedded in the mix that combines characteristics normal stereo (speakers) and binaural stereo (headphones). It is not easy or trivial, because the two types of stereophony have fundamental differences, but I try. Speaker stereo requires much larger ILD than headphone stereo, but mostly on low frequencies. That's why I employ smaller ILD at low frequencies and large ILD at high frequencies. ITD is used mostly to "pan" low frequencies if needed.

 

[gregorio]

OK, so there are bench measure proxies for soundstage.

No, there aren’t. Again, there are fundamental properties of audio signals, FR, levels, etc., many of which can affect our perception of soundstage but you seem stuck on the (false) concept that soundstage is somehow a real thing, some sort of audio property that we don’t or can’t measure, presumably because you perceive soundstage. This concept is incorrect, soundstage not a real thing/audio property, it can’t be measured because it’s an illusion, a manipulation of human perception. The reason that recordings appear to have soundstage is because recordings are created by engineers, who obviously also have human perception, who manipulate various audio properties (using their perception as a reference) in order to create the illusion. We cannot measure an illusion.

One of the claims in this and other threads is that DACs and amplifiers measure so well, there could not be any contribution to in-room performance as it relates to soundstage. Some questions then: 1) how should those measures relate to perceptions of soundstage by listeners specifically? 2) have you experienced any differences in how electronics contribute to how you experience soundstage in your home stereo system(s) when swapping a single piece of electronics ahead of the speakers? 3) if you did, were you able to associate those soundstage differences to specific specifications or bench tests of the equipment in question? or 4) did you experience electronics related differences in how you experienced soundstage in your system that could not be traced back to specifications or bench tests?

1. Those measures do NOT “relate to perceptions of soundstage by listeners specifically”, so there is no “how should” they relate! Again, there are just audio properties, that’s it, there is nothing else we can measure when measuring audio. Some of those measures (on their own and in combination) may or may not affect our perception/illusion of soundstage but obviously only if they are of sufficient magnitude to be audible but they do not “specifically” relate.
2. Yes, of course, some home systems have electronics with different functionality and some of it is deliberately designed to provide options for altering soundstage, for example many AVRs provide algorithmic reverb presets to artificially create the impression of an Arena or other acoustic space. I’m presuming you’re not referring to that type of functionality or to EQ, room correction and other such equipment “ahead of the speakers” but to straight DACs and amps that are not supposed to be changing the signal? In which case, the answer is “yes” but in specific scenarios, mostly user error scenarios. For example, incorrect gain-staging requiring a very low amp setting which in some cases can cause an audible channel imbalance and possibly/probably a change in soundstage perception. I have also heard such differences with certain tube amps and a NOS DACs but of course these are not covered by the condition of “not supposed to be changing the signal”.
3. No, I was not always able to associate soundstage differences I perceived with measured differences, quite commonly in fact. However, closer examination of these instances, using a null test, blind test or some other objective determination (depending on the equipment I was changing), always revealed it to be due to perceptual error.
4. Not “electronics related differences” that couldn’t be traced back to some type of measurement and if you think about it, how could there be? These are electronic devices designed and built by humans for a specific purpose, they are not things we mined, found growing on trees or saw in space, that science has to try to explain what they are, how they work and how to measure them. They are “technology”, our own application of the science we already know, not the application of magic or something else science does not know.

G