+1 noromance

it’s on the record.  On certain LPs I can hear people talking to my right of my seating position. There is a party on a Donald Fagan album. People are clapping and talking around me  

Bent
 

Very interesting thanks 

...

Stereophile Review, Pass Labs XA60.8, Jim Austin, November 22, 2017

Nelson Pass said in my interview with him in the September 2017 issue. He noted how his First Watt experiments with amplifiers based on static-induction transistors (SITs) led to an insight into the subjective effects of second-harmonic distortion, particularly its phase, and in turn influenced his design of his big Pass Labs amps. "The SIT being very much like a triode, it is easy to make a single bias adjustment which affects the second harmonic distortion of the device, ranging from a relatively large amount [of] positive phase second [harmonic] through a null point with no second [harmonic], to large, negative phase second-harmonic distortion," he said. "Negative-phase second harmonic tends to expand the perception of front-to-back space in the soundstage, separating instruments a bit. Positive phase does the opposite, putting things subjectively closer and 'in your face.'"

Should spatial perception x what you describe differ for, say, bass in outdoor setups (I am sorry - I realize this is slightly tangential from the OP query)?

@benanders Outdoors we can sort out where bass notes come from. But in most rooms indoors we cannot since it takes a few iterations of the bass note to pass our ears before we can know what bass note it is. By that time (in most rooms) the bass has bounced off of several walls and so is 100% reverberant.

It doesn't happen. It's a placebo. The only reason you'd hear a difference is if one amp is underpowered and the other has more power to drive the speaker, assuming the speaker can handle it.

Personal subjective theory. As I improved my system with lower capacitance cables and interconnects, purchased a WiFi streamer with a better DAC and lowered the line level from the DAC to my previously serviced older Crown PS 200, the sound stage widened noticeably…I think because the rest of the system had increased frequency response and decreased distortion. The difference had more to do with signal in and cable affect on speaker level signal out than the amp itself, maybe.

If love or music as some specific arrangement of sounds cannot be measured as such do they exist ?

A children will say yes...

Soundstage is an acoustic perceived parameters pertaining to many contributing factors with are related to the electrical, mechanical and acoustical characteristics of the gear /room but also to the inner ears frequency response and to the HTRF of each one of us and also to the recording acoustic trade-off choices of each specfic album...

Soundstage cannot be measured in a simple linear way but it result from a perfectly contrallable set of parameters.. I put it under my own control in my room and sculpt it in a way and the form i wanted too ...

Most things exist in spite of being non measurable in a simple way or even in a complex way ... Galileo eliminated what is not simply measurable, as taste ,colors,sounds,odors and feelings and called them secondary qualities. not measurable as the primary qualities : size,position and location , form and motion to start physics...

But physics as it is now is a drop in the bucket of knowledge ... 😁

We need a new physics by the way...

This dude in India work to create a new physics among others..

If soundstage cannot be measured, does it exist?

If soundstage cannot be measured, does it exist?  

My sugden a21se combined with tannoy eatons throws a tremendous Soundstage. I believe it to be a very synergistic pairing. It helps that I also use a tavish tube phono preamp.

« This thesis investigates the extent of the human ability to perceive changes in the
direction of low-frequency sound sources, within the range of 31.5 and 100 Hz, in
a large, highly damped environment.»

... «It has also been demonstrated that the
presence of modal behaviour in the listening environment hinders the localisation
ability, as it leads to erroneous ITD cues. This fact could have contributed to the
belief that, as a rule, low-frequency sound sources are not localisable, a view which
this thesis aims to refute.»

Auditory localisation of
low-frequency sound sources
Mădălina Anamaria Năstasă

Auditory localisation of
low-frequency sound sources
Mădălina Anamaria Năstasă
School of Electrical Engineering
Thesis submitted for examination for the degree of Master of
Science in Technology.
Espoo 29.07.2022

https://aaltodoc.aalto.fi/server/api/core/bitstreams/e43fa993-e3c9-4784-a6c2-05a292aab188/content

atmasphere

11,505 posts

03-08-2024 at 12:15am

”is this statement meant to rule out bass as being important to listener perception of soundstage?”

@benanders Yes. Bass (20Hz to about 150Hz) is important if you want to get the tonality right but it has little to do with imaging and sound stage- the lower the frequency the more this is true. Below 80Hz in most listener’s rooms the bass is 100% reverberant (which is why subwoofers don’t have to be in the same location as the main speakers if crossed over below 80Hz).

@atmasphere I’d assumed that has more to do with a discrepancy between wavelengths and reflection time vs. boundary dimensions, than with how we perceive bass overall (granted, research indicates certain higher frequencies are disproportionately influential on our sense of spatial scale). Should spatial perception x what you describe differ for, say, bass in outdoor setups (I am sorry - I realize this is slightly tangential from the OP query)?

You can try a simple experiment to show how this is so. If you use midrange drivers and tweeters as speakers you’ll find they can image nicely, but if you use only woofers that are rolled off at a normal crossover point you’ll find the image very indistinct or non-existent, depending on the woofer.

This made me chuckle at myself. Bass in my setup comes from stereo subs that can go up to ~180 Hz (I keep them crossed at 100 Hz). When I was setting them some years back, I did play them without the towers but directed my attention to measurements vs. room modes (vs. listening impressions); I admittedly wasn’t focused on soundstage of given tracks. “Tell me you already knew something but didn’t know how to say it ‘til just now.”

I’ll aim to give that simple experiment a whirl this weekend if time permits. Thanks again.

I would think that class A amps with less negative feedback would have a bigger soundstage, that could be one of the reasons many tube amps have a great soundstage.

is this statement meant to rule out bass as being important to listener perception of soundstage?

@benanders Yes. Bass (20Hz to about 150Hz) is important if you want to get the tonality right but it has little to do with imaging and sound stage- the lower the frequency the more this is true. Below 80Hz in most listener's rooms the bass is 100% reverberant (which is why subwoofers don't have to be in the same location as the main speakers if crossed over below 80Hz).

You can try a simple experiment to show how this is so. If you use midrange drivers and tweeters as speakers you'll find they can image nicely, but if you use only woofers that are rolled off at a normal crossover point you'll find the image very indistinct or non-existent, depending on the woofer.

I must admit that it is fun imagining my large deep soundstage emanating from my reference system. So damn good that I suspect it ain’t real - its a repeating simulation.

As a monoral signal has no separation, by the same token, it would seem to me that an amp with better channel separation would throw a wider soundstage than one with poor separation.

BUT, perhaps a bit of out-of-phase channel crosstalk could make the image wider? 

Also, one would want both channels to be/track as identically as possible, to keep the soundstage from shifting about.  If a channel lacks what the other has, it can't really produce mono for a proper center image at that frequency/volume.  This would apply anywhere along the audio chain.

atmasphere

11,504 posts

03-07-2024 at 12:37am

…impedance issues in the bass region, which has nothing to do with presenting a sound stage.

@atmasphere is this statement meant to rule out bass as being important to listener perception of soundstage? That would seem doubtful… query not intended as a challenge for which I have empirical grounds, just interested.

atmasphere

11,504 posts

03-07-2024 at 12:37am

…Our OTLs are known for a very good soundstage and yet they have a high output impedance so can’t deliver the power into lower impedances. Our class D can- but the sound stage of our class D vs our OTLs is nearly identical.

And this would make that potential discrepancy even more interesting.

crustycoot

572 posts

03-06-2024 at 10:50pm

…I also believe the preamp is more instrumental in establishing soundstage than the power amp is in my experience.

Not sure you intended it but, that’s gonna be the pun to beat today.

I have a pair of Thiel CS6 speakers that dip to around 2 ohms in part of the frequency spectrum. I run them with a Krell KSA 300S that doubles its power down to one ohm (300 watts @ 8 ohms, 2400 watts @ 1 ohm). When I took the amp in for recapping I tried hooking up my Onkyo A/V receiver to the Thiels. The results were laughable. The Onkyo sounded like an AM radio. The soundstage was flat as a pancake. I figured there would be a difference but I had no idea it would be that dramatic.

@8th-note Your conclusion might not be accurate - its very likely that current had nothing to do with it.

To present a sound stage the mids and highs need to be reproduced properly. You usually don't need current for that since most speakers are fairly easy to drive in the mids and highs. Theils tend to have their weird impedance issues in the bass region, which has nothing to do with presenting a sound stage.

If the Onkyo has a power amp input I would run your preamp into that and see if you still say the same thing. Of course by now the issue might be moot since this is an anecdote; my point is that there were a lot more variables going on here than you initially surmised.

Our OTLs are known for a very good soundstage and yet they have a high output impedance so can't deliver the power into lower impedances. Our class D can- but the sound stage of our class D vs our OTLs is nearly identical.

I have one more theory. Amps differ in their ability to provide current into low impedance and phase shifted loads. The type of amp (class A for example) doesn't tell you how well it provides current. If the speakers in question have an impedance dip in part of the frequency range and one amp provides more current into low impedance loads, the speakers will have a different frequency response between one amp and the other. This difference in frequency response could explain issues like a difference in soundstage.

I've heard a dramatic example of this. I have a pair of Thiel CS6 speakers that dip to around 2 ohms in part of the frequency spectrum. I run them with a Krell KSA 300S that doubles its power down to one ohm (300 watts @ 8 ohms, 2400 watts @ 1 ohm). When I took the amp in for recapping I tried hooking up my Onkyo A/V receiver to the Thiels. The results were laughable. The Onkyo sounded like an AM radio. The soundstage was flat as a pancake. I figured there would be a difference but I had no idea it would be that dramatic.

IMO, many if not most audiophiles do not fully appreciate the impact that speaker impedance curves have on the sound of a particular amplifier. Two amps with identical power at 8 ohms can sound radically different on a given set of speakers depending on the speakers' impedance curve and the ability of the amps to provide current into difficult loads.

In the “everything matters” way of thinking, the only valid test setup is to use identical conditions for both DUTs, and to introduce nothing extra into the apparatus that isn’t required for critical listening…that means no ABX switches, disconnecting and reassembling hookups, etc., which takes time.  Critically matching playback level is known to be a necessity in assessing quality.  How many of us can recall the sound well enough to judge in light of these factors?  I am in agreement with Jasonbourne on this one…I also believe the preamp is more instrumental in establishing soundstage than the power amp is in my experience.

+1 @hilde45 @atmasphere @mapman @mahgister

Thank you all for distilling things properly. These important factors are often overlooked and/or usurped by either hyperbole or oscilloscopes.

Two things: lack of phase shift and aural effects having to do with the 2nd and 3rd harmonics, the latter of which can make an amp seem more detailed and spacious.

Thanks @atmasphere

The perception of a larger soundstage can be influenced by various factors, including the design and characteristics of the amplifier itself. Here are a few reasons why some amplifiers may be perceived to have a bigger soundstage:

1. Power and dynamics
2. Low distortion
3. Channel separation
4. Transient response
5. Room acoustics

Thanks @mapman

Isn’t it nice to get straightforward and technical answers rather than responses that it’s user-error or placebo effect? Lazy thinking which blames listeners first is so enervating.

I like the way a seasoned amp maker put it:

Competently designed speakers can sound different from each other.

Competently designed amplifiers can sound different from each other, but less so.

Mapman is right because he exposed almost all factors..

i will add vibrations resonance control and the room/house electrical grid factors...

The main factor , save if the design of the gear is not very good, room acoustic controls... For sure it takes a good amplifier but it is one of many factors...

With the same relatively good amplifier i can transform completely the soundstage impression by modifying the room... I did it by the way... It is not an opinion but a fact...

My soundstage was filling completely the room around me and beside me with no sound coming from the speakers plane ...the main fact was not my choice of amplifier , even if the amplifier must be minimally good for sure otherwise nothing work well , but the main factors was acoustics understanding and disposition of many devices of all kind to do the job ( resonators, and others devices)

But atmasphere explained why some amplifier do a good job and are better than others for the soundstage and timbre...

At the end it will be acoustic room disposition though the main factor...

When it comes to audio amplifiers, the concept of a "soundstage" refers to the spatial representation and imaging of sound within a recording. It's the ability of an audio system to create a three-dimensional sonic image, where instruments and voices are perceived as coming from specific locations within the soundstage.

The perception of a larger soundstage can be influenced by various factors, including the design and characteristics of the amplifier itself. Here are a few reasons why some amplifiers may be perceived to have a bigger soundstage:

1. Power and dynamics: Amplifiers with higher power output and better dynamic range can reproduce music with greater energy and impact. This can result in a more expansive and immersive soundstage, as the increased power allows for better control over the speakers and the ability to accurately reproduce subtle details in the recording.

2. Low distortion: Amplifiers with low levels of distortion can provide a cleaner and more accurate representation of the audio signal. Distortion can smear the soundstage and reduce the clarity and separation of instruments and voices within the recording. By minimizing distortion, an amplifier can help create a more spacious and defined soundstage.

3. Channel separation: Good channel separation is essential for creating a wide and precise soundstage. It refers to the ability of an amplifier to keep the left and right audio channels separate, preventing crosstalk and ensuring accurate imaging. Amplifiers with excellent channel separation can help localize sounds more precisely and create a wider sense of space.

4. Transient response: The transient response of an amplifier refers to its ability to accurately reproduce sudden changes in the music, such as the attack and decay of musical notes. Amplifiers with fast and precise transient response can provide better imaging and localization, which contributes to a more expansive soundstage.

5. Room acoustics: The soundstage of an audio system is not solely determined by the amplifier itself but is also influenced by the listening environment. Factors like room size, shape, and acoustic treatment can impact the perception of the soundstage. However, a well-designed amplifier can complement the room acoustics and maximize the potential of the soundstage.

It's important to note that the contribution of the amplifier to the overall soundstage is just one piece of the puzzle. Other components in the audio chain, such as speakers, source material, and recording quality, also play significant roles in shaping the perceived soundstage. Therefore, achieving a larger soundstage is a combination of careful system design and optimization across all components.

there are resonances occurring in the system that are causing an effect of reverberation. Examples include feedback

That seems plausible.

One amplifier be a pitcher. The other be an outfielder?

Two reasons:

1. It’s on the recording, and the system is reproducing that recording faithfully because it has the necessary qualities to achieve that.

2. It’s not on the recording, and there are resonances occurring in the system that are causing an effect of reverberation. Examples include feedback from physical vibrations impacting the casework, the electronics, or the mechanical components in the source.

Back in the late ’90s a dealer let me take home a Mesa Baron for the weekend.

I was immediately intrigued and impressed by how up front and close the soundstage was (particularly the vocalist) and how it filled the room to an extent I had never experienced before. At the time I was running a Cary SLA 70 Signature (Cary’s entry level push pull amp) and the reason I did not buy the Mesa and stayed with the Cary (for the time being) was that the soundstage of the Mesa was not nearly as clean and defined as that of the Cary. As a matter of fact, the way I described the soundstage of the Mesa was as being "smoky."

Since then I have owned a couple of other amps (a pair of ARCs and a larger Cary) which provided a larger soundstage, but really nothing quite the same as what the Mesa did, and I have often wondered about that.

I did try to post a link for the Mesa, as I always thought it was a looker, but for some reason A’gon won’t let me do that.

Listening is a skill. It requires lots of practice and study to learn the vocabulary of standard descriptive terms. For experienced amateurs and professionals assessing sound qualities are relatively easy and comparable across listeners. Kind of like reading X-rays. For the professional… he’ll just rattle off what this is and what that is while to the untrained eye, all you see is fuzzy gray areas.

So all this discussion about how subjective sound is, or it is some trick of the mind comes from inexperience. I can take three different experiencesed audiophiles and get exactly the same description of sound qualities of a system or changes in that system exactly and consistently. Most of the subjectivity involves words like good or better… value statements about your values… what you like and don’t like.

I have very little experience of tube amps, but I do remember a wide soundstage.

However, the review I watched compared two solid state amps, both class A.

still don’t understand why one would would throw a wider soundstage than the other.

I like tube amps, particularly low-powered ones, and they do seem to present a larger soundstage than many good solid state amps.  My personal suspicion is that they do so because of some kind of phase anomaly.  I don't care if it is a kind of distortion or defect, if that is the case, it sounds good to me.  I know that transformers don't behave perfectly, particularly when it comes to phase shifting, and the amps I particularly like have a LOT of iron in them--input transformers, interstage transformers, and output transformers. 

Why do some amplifiers throw a bigger soundstage than others?

@rrm Two things: lack of phase shift and aural effects having to do with the 2nd and 3rd harmonics, the latter of which can make an amp seem more detailed and spacious.

Why do tube amps generally have larger sound stages? maybe its a harmonic effect some amp do them well some don't.  Is it distortion effects, even/odd order effects?

clarity maybe, but I've heard some older vintage tube gear throw a huge sound stage with out great detail and clarity levels. so really doesn't hold up in my experience. 

Even though the OP used a YouTube video as an example its still a valid question that many of us have experienced when trying new gear. 

@jasonbourne71 +2

Mike

@jasonbourne71 

Right on.

IMHO, clarity is one of the most significant contributors to soundstage. If your speakers have good phase coherency, and are mated with an amp with good clarity, you should get a good soundstage if properly setup.

What you heard is a subjective opinion by a person who has not done a careful blind test. Therefore the premise that one amp has a wider soundstage is suspect.