The concept of 'sound stage' seen in reviews.

[jarchi]

If you look at big and expensive amp and dac reviews on the Internet, there is a story that people commonly tell.

It's a wider sound stage and feels airy? the reverberation increases and creates a sense of depth'.

Let me give you an example.


"... ... When you switch from the normal OOOO to the OO, the first thing you notice is the extension which is improving. While there also is a wider sound stage, I’m mostly talking about more space and air between the notes, and that from top to bottom, but mostly in the mids area. As a result the original Euforia sounds more intimate compared to the AE, but it in fact it s not intimate per say, it just gives that impression as the AE is even better. ... ..."


This article describes when Headfonia, a fairly popular headphone and peripheral review site, switched from an expensive amplifier to its higher version.

I've seen so many of these expressions of stage size changes. But I've never seen a single person say what principle, or what measurement, can represent this. In other words, is there still a technical limitation today that can objectively measure the sound of headphone amplifiers, and there is an area that must only be judged by the ears?

However, the manufacturer's position on the amplifier should be different. Because you can't produce something you don't know what you're going to do and how you're going to make it If you need to tune the size of the stage when you create an amplifier, you need to create your own parts or circuits that affect it. And if a component changes, you should be able to quantify it. If this is a manufacturing know-how and we can't let the consumer know?, ok we can't say nothing.


For your information, the reviewer below lists the differences between the two amplifiers. Of course it's the same as the manufacturer said.


The new OOOO Edition basically is an upgraded version of the original. New this time:

• Neotech UP-OCC Single crystal signal wiring – extremely pure monocrystalic copper wire, teflon coated – able to transmit signal faster, and with less distortion than OFC or silver wires, comparing to pure silver wires (as used in “regular” Euforia) it makes the top-end of the spectrum sound richer yet less fatiguing
• Higher grade internals including ClarityCap capacitors with CopperConnect technology- for extra smoothness and clarity
• New low-noise-design power transformer – provides even better electromagnetic interference isolation
• Redesigned Constant-current source modules to give rock-solid operating conditions, regardless of the external factors
• Special finish – high gloss space grey applied using highest quality automotive painting process

So the reviewer is saying that changing the internal wiring, capacitors, transformers, and Constant-current source modules can help to expand the staging and improve the sound quality. But we don't know how it affects sound without studying audio deeply. Actually, I'm really curious about this.

And I think this. Today, there are many sites where you can objectively review devices through measuring instruments like here, and Semi-professionals are also in an atmosphere of exchanging opinions with people about technology, so many manufacturers expose specifications when they launch products. Even in this situation, it is not thought that there will be unknown or hidden areas behind the measurement.

I've lived in headphile's life a lot and ... yeh it means I've heard a lot of things too, but I don't think I've ever felt that the stage has expanded dramatically. However, it may not be all that I have experienced. Interestingly, this staging story comes at a very high price product. So I'm also thinking about this. Maybe this is a kind of fantasy marketing using the rarity of the experience of these products.

So I think of it today too. If staging width is actually adjustable, and if some amplifiers actually produce wider and more spacious imaging, what are the specs that can be objectively identified? And will the parts above really affect the staging change? If so, what is the principle?

 

[GXAlan]

If you listen in phase and out of phase, the out of phase playback has a wider soundstage although you lose the precision. It is possible that phase errors can fatten a sound stage if the phase error is specific to certain frequencies.

A stereo amp with very poor cross talk may sound monaural. A wider soundstage is likely also enhanced by better crosstalk measurements.

The first is inaccurate fattening of the sound. The second is accurate preservation of the stereo recording. In real life, some combination of accuracy and inaccuracy leads to soundstage.

 

[RayDunzl]

Experience:

With two speakers there are two ways that a sound can be located in the soundfield:

1. Difference in amplitude only - the sound moves toward the louder speaker

2. Difference in time - the sound moves toward the earlier speaker, and can even move past it.

The two methods are not mutually exclusive, both can be used simultaneously.

It is possible for a sound to seem to come from beyond the speaker (left or right), depending on the phase (timing).

Some recording techniques - QSound is an example - can create a 180 degree wide soundfield, I presume with manipulation of the phase. As long as you continue to "look" straight ahead between the speakers, the sound can come from 90 degrees left or right of center. If you look to the left or right, the effect vanishes. It's a little spooky sometimes.

Precision in the playback preserves the clues in whatever has been recorded.

Other tricks can provide some sensation of depth, but I find it more limited than the left-right images.

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I'm not a recording engineer, but have experimented on my own with the above.

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Depending, the soundstage can be a stereo blur or sharply focused, to use visual terms.

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Opinion:

As for the "high end" aspect, my "higher end" system is better at "soundstage" than lesser systems I have and have had. I put it down to low distortion (precision), matched channels, and power (think irresistable force more than just quantity).

 

[maverickronin]

Soundstage is a psychoacoustic illusion and there is no accepted way to measure it.

For headphones, the closest I've ever seen is at Rtings where they compare the headphone's response on a dummy head to the dummy head's pinna transfer function. It's definitely a good start and that is almost certainly the dominant factor but the weightings seem to be pulled out of thin air and not anchored to any studies of actual perception. OTOH, I'm not aware of any public research in this area either

For speakers I've seen various research on how sidewall reflections can lead to "image broadening" but the mostly seem to be focused on when a reflection is perceived as a separate echo. Maybe someone more versed in speaker research can chime in.

As to what affects soundstage we can immediately rule out almost all DACs and cables and many amps as they are usually fairly transparent. This would also imply that any actual differences are caused by a non-transparent device. This also corresponds with my personal experience as well. Some particularly nonlinear headamps (often OTL tube designs) seem to have greater sense of "space" or "air". Assuming I'm not imagining it this may be from distortion components increasing the overall high frequency content.

The transducers themselves (and the room for speakers) are the most important components in determining soundstage.