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Properties of speakers that creates a large and precise soundstage

sigbergaudio

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There are some similar threads about what imaging and soundstaging even is, and some threads about how to measure it (we're not great at that). In this thread I thought it would be interesting to have a look what properties is likely to enable a speaker to be good at this.

My (!) definition of "good" would be to be able to present a large soundstage. With "large", I mean the experience of sound being presented well beyond the speakers in all dimensions. Width, depth, height. I also mean the experience of a clear perception of where within this space different sounds are located. Finally, this also results in an experience of the music just being present in your listening space, not coming from the speakers. Often explained as speakers "vanishing" in subjective speaker reviews.

Commercial disclaimer: Imaging & soundstage are qualities I find important, so I strive to achieve this in my designs. You will therefore necessarily find that the list below matches well with our designs. My intent of this thread is not to discuss our designs specifically, but to discuss the technical properties enabling this quality from a general perspective. Possibly also going into detail on what is likely most important, how much the implementation matters (can you check the boxes on this list and still fail?), and wherever else this thread may lead us. :) Personally I think this is a very interesting topic, hopefully others agree.

Below is a list of important factors (not necessarily in order of importance) based on my experience.
  1. Point source. I don't think this is controversial, and I think this is almost a prerequisite. Coaxial drivers are of course the easy approach to this. There are speakers with traditional drivers that sound big too, but interestingly it's often 2-way speakers with relatively small drivers and/or with at least the midrange and tweeter placed pretty close to each other. Exactly why this elevates the quality of soundstage and imaging I'm not sure.
  2. Even off-axis response / controlled directivity, so that reflections feel like a natural addition to the direct sound as opposed to being perceived as a distraction or noise.
  3. Linear phase crossover between the tweeter and midrange.
  4. Less late reflections. So a well damped room, speakers not too far away, and/or cardioid speakers.
  5. Enough level and capacity in both the deep bass and the midbass. This I think is another relatively well known thing, that well defined, deep bass can often add to the sensation of space.

EDIT: Additions to the list based on the discussion, with my comments (will edit again as the discussion progresses):
6. Placement and toe-in naturally affects this quality.
6b. Many argue that the speakers have to be well away from the front wall for good three dimensional, especially in the depth plane. I find this to partially true, but suspect there is one area where the mind plays some tricks on us. Seeing a speaker close to the wall, makes it harder to accept depth cues.
7. Sidewall reflections. This definitely affects this quality, but personally I've had varied results which make this a somewhat confusing one. In several rooms I've ended up not dampening the sidewalls for the best soundstage, while in others the opposite was true. o_O
8.
Directivity (also mentioned in point 2) - I'm not sure it's entirely clear what works here. My own designs are I guess somewhere in between wide and narrow directivity, and that subjectively works very well, but that's not to say that a different approach can't work well too.
9. Well tamed low-end (so good extension with smooth response) has also been suggested. I'm not sure if that is true directly, or perhaps indirectly due to the fact that uneven bass takes away our attention from the rest.

EDIT #2:
Adding an interesting quote from @Duke that I think perhaps quite precisely describes what we are after: "The spatial cues on the recording are perceptually dominant over the spatial cues of the playback room."

General reflection:
We could perhaps form the theory that there are a number of elements that need to come together to create this magic, and the exact combination of ingredients may not be the same for each room(?). Which may be one reason why it's a bit elusive. The same speaker definitely doesn't present the same level of soundstage across rooms, so the room + placement is a significant factor.


What else? Agree/disagre? Any reflections (pun intended) to share on the subject? :)
 
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I think it's important to recognize that it's a psychoacoustic effect, and it seems to be supported by visual reinforcement that the sound is coming from free space.

I commonly read and have similarly experienced that the effect is stronger when the speakers are standing out in free space away from the front wall, and when there's nothing like a television placed between the speakers.

I don't think this can be attributed to acoustics and note that Genelec advocates for placing speakers very close to the front wall when possible. And a TV in the room that isn't interfering with first reflections shouldn't change the acoustic environment significantly. But the perception of sound emanating from free space heightens the experiences vs the sound appearing to come from the wall or a television screen.

I believe this is also a part of why the classic audiophile setup of chunky amps on the floor between speakers is compelling too. It helps to build a visual stage around where you perceive the sound to come from.
 
I think it's important to recognize that it's a psychoacoustic effect, and it seems to be supported by visual reinforcement that the sound is coming from free space.

I commonly read and have similarly experienced that the effect is stronger when the speakers are standing out in free space away from the front wall, and when there's nothing like a television placed between the speakers.

I don't think this can be attributed to acoustics and note that Genelec advocates for placing speakers very close to the front wall when possible. And a TV in the room that isn't interfering with first reflections shouldn't change the acoustic environment significantly. But the perception of sound emanating from free space heightens the experiences vs the sound appearing to come from the wall or a television screen.

I believe this is also a part of why the classic audiophile setup of chunky amps on the floor between speakers is compelling too. It helps to build a visual stage around where you perceive the sound to come from.
Yes, psychoacoustics are very important. For example, listening to music in the dark, with the lights off, will give a very different soundstage compared to listening to music with the lights on.
No better way to make the speakers disappear than to turn off the lights so you don’t see them.
In my case, if I close my eyes, the soundstage gets completely ruined and chaotic.

While properly engineered speakers help provide a better soundstage, I think the most important part is to set up the speakers for proper stereo imaging, which, in a household usually conflicts with a lot of things.
 
The biggest I have ever heard came from horns (big ones).
I my set-up with what I can use it seems that moving them away from their back wall (I have tried from zero to 1.6 meters,my installers position is at 1.10) trades constantly with height vs wideness (side walls are about 4 meters from each speaker,I use the long dimension).

I can't say I hear soundstage expanding well beyond the speakers on sides except with some strange plays (like Space Oddity) probably made as such and vocals height is just above tweeter usually and at an arc with choruses.
 
IMO:

Speakers need to fool you as much as possible, meaning they should not reveal where they are. Adding more speakers is one trick, but limiting the question to stereo the usual factors are important:
- no resonances - linear frequency response - see below though*
- no or only weak early reflections from the direction of the speakers (within a few ms)
- not to0 high level or too early reflections from side-walls

*make sure that the 1 kHz-5 kHz region is "audibly smooth". It may require some deviations from perfect flat or even frequency response frontal arrived sound and lateral dispersion (more energy 1-2 kHz, less energy 3-4 kHz). And also slightly different depending on the listening distance (different DR ratio).
 
I believe this is also a part of why the classic audiophile setup of chunky amps on the floor between speakers is compelling too. It helps to build a visual stage around where you perceive the sound to come from.
I have a radiator in that position. It's a very musical radiator :D
 
I see a few answers implying that this is largely made up or imagined. I assure you it is not, but of course our minds play tricks on us as well, like being able to localize an asymmetrically placed subwoofer solely because you can see it. But there is a lot more to it than that. Proper placement should have been on the list too of course.

I've also discovered that not everyone cares about or even understand / recognize this quality. I'm not sure if this is a difference in the person itself, due to their taste in music (black metal is not generally known for recordings with a wide soundstage for instance) a combination or something else.
 
There are some similar threads about what imaging and soundstaging even is, and some threads about how to measure it (we're not great at that). In this thread I thought it would be interesting to have a look what properties is likely to enable a speaker to be good at this.

My (!) definition of "good" would be to be able to present a large soundstage. With "large", I mean the experience of sound being presented well beyond the speakers in all dimensions. Width, depth, height. I also mean the experience of a clear perception of where within this space different sounds are located. Finally, this also results in an experience of the music just being present in your listening space, not coming from the speakers. Often explained as speakers "vanishing" in subjective speaker reviews.

Commercial disclaimer: Imaging & soundstage are qualities I find important, so I strive to achieve this in my designs. You will therefore necessarily find that the list below matches well with our designs. My intent of this thread is not to discuss our designs specifically, but to discuss the technical properties enabling this quality from a general perspective. Possibly also going into detail on what is likely most important, how much the implementation matters (can you check the boxes on this list and still fail?), and wherever else this thread may lead us. :) Personally I think this is a very interesting topic, hopefully others agree.

Below is a list of important factors (not necessarily in order of importance) based on my experience.
  1. Point source. I don't think this is controversial, and I think this is almost a prerequisite. Coaxial drivers are of course the easy approach to this. There are speakers with traditional drivers that sound big too, but interestingly it's often 2-way speakers with relatively small drivers and/or with at least the midrange and tweeter placed pretty close to each other. Exactly why this elevates the quality of soundstage and imaging I'm not sure.
  2. Even off-axis response / controlled directivity, so that reflections feel like a natural addition to the direct sound as opposed to being perceived as a distraction or noise.
  3. Linear phase crossover between the tweeter and midrange.
  4. Less late reflections. So a well damped room, speakers not too far away, and/or cardioid speakers.
  5. Enough level and capacity in both the deep bass and the midbass. This I think is another relatively well known thing, that well defined, deep bass can often add to the sensation of space.


What else? Agree/disagre? Any reflections (pun intended) to share on the subject? :)
Interesting question ! :)

How to get a large and precise soundstage - my take :

1. Point source speaker ( absolutely necessary )
2. A good digital source with good recordings ( Dac and preamp )
3. A very clean and transparent poweramp
4. A linear phase crossover or no crossover
5. Small corrections with PEQ for the stereo system faults ( + 1,5 dB Q= 3 at 1,7 kHz ) and - 1,5 dB Q= 3 at 3,5 kHz.

I have the largest soundstage ever in my room, ( bigger than it was with my Genelec SAM 8340 monitors,) and at the same time, the sound is very pinpoint and precise.
I use a Markaudio DIY loudspeaker, a WiiM pro with digital PEQ connected to a Rega dac R and an Audiophonics Hypex ncore 250 amplifier.

I dont believe that good directivity using a waveguide in a two way speaker can be as good as a true point source loudspeaker. My last two speakers with waveguides ( dsp Hybrid and SAM monitors ) did measure very well, but a good point source has some qualities that no multiway speaker have. No crossover is 100% transparent to the music.
 
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I don't want a soundstage that's always big, usually achieved by playing with first reflections, but one that reflects the soundstage of the recording, ie accurately reproduces the reverberations on that recording.

A recording made in a cathedral should have a very different soundstage from one made in a toilet cubicle!
 
The ability of a speaker to resolve details in the audio signal contributes as well. The feeling of depth and space can be conveyed by low level reverbs which some speakers are more capable of reproducing than others.
 
I see a few answers implying that this is largely made up or imagined. I assure you it is not, but of course our minds play tricks on us as well, like being able to localize an asymmetrically placed subwoofer solely because you can see it. But there is a lot more to it than that. Proper placement should have been on the list too of course.

I've also discovered that not everyone cares about or even understand / recognize this quality. I'm not sure if this is a difference in the person itself, due to their taste in music (black metal is not generally known for recordings with a wide soundstage for instance) a combination or something else.
I don't think that it is largely made up or a trick... I was simply adding my piece on other aspects that contribute in addition to acoustic requirements.
 
Wide is sometimes the enemy of precise, IMO. Sensing a decent soundstage anywhere in a normal room outside a fairly near and centered position seems to rely on even dispersion.
 
Is it true that coaxials have a more precise but smaller soundstage than conventional speakers ?
 
Is it true that coaxials have a more precise but smaller soundstage than conventional speakers ?

No. A coaxial typically have a larger soundstage than conventional speakers.
 
The biggest I have ever heard came from horns (big ones).
I my set-up with what I can use it seems that moving them away from their back wall (I have tried from zero to 1.6 meters,my installers position is at 1.10) trades constantly with height vs wideness (side walls are about 4 meters from each speaker,I use the long dimension).

I can't say I hear soundstage expanding well beyond the speakers on sides except with some strange plays (like Space Oddity) probably made as such and vocals height is just above tweeter usually and at an arc with choruses.

Interesting. Doesn't sound like you have a very large soundstage now then. I guess the relatively far distance from each sidewall could contribute to that. And/or it could be the speakers themselves. So do you get even less width if you move them out in the room, is that what you are saying?
 
Wide is sometimes the enemy of precise, IMO. Sensing a decent soundstage anywhere in a normal room outside a fairly near and centered position seems to rely on even dispersion.

Yes, so the trick is to get both (at least if that's what's the intent of the recording). :) Not just a large, diffuse soundfield, but a large soundstage where it feels like you can single out the different musicians or sounds.

As pointed out in other threads that isn't necessarily an accurate representation of a live event. In an intimate live event you can get a combination of auditory and visual cues as to where sound is coming from (you can see the tuba player, you can see the drummer), but the radiation of sound from those instruments are very different than from a speaker. But I still find a large, immersive soundstage to be very rewarding and captivating.

I guess some of you have noticed how music often sounds larger than life and somehow better in soundtracks of movies. There is some resemblance to that effect, but with 2-channel audio. I find it fascinating.
 
Two additional criteria from my POV, besides some important speaker characteristics as given by others already:
- slow mono frequency sweep stays in the perceived center as much as possible
- speakers that "disappear" as much as possible, giving away only the direction, not the distance. Floor bounce must also be suppressed for this, besides overall good room acoustics (!). Distance perception shall mainly scale with level,*) the louder the closer the perceived sound source (dry sound, no reverb), sometimes even way in front of the speaker baseline.

That tends to give a very precise and uniform soundstage, albeit a bit bland and small at low levels. But the higher level, the larger the contrast between the dry sounds and the reverb tails in the recording which is one thing that makes a soundstage huge, especially when those reverb tails have some 3D magic encoded in.

Well-balanced DRC on top of that is then the icing on the cake.

All of this IMHO is influenced a lot by personal preferences. I confess that I sometimes add a little bit of early reflections and reverb via plugins to my playback to make things a bit more exciting and immersive. As well as a lot of EQ when I think I need it. When it sounds better it sounds better ;-)
 
Yes, so the trick is to get both (at least if that's what's the intent of the recording). :) Not just a large, diffuse soundfield, but a large soundstage where it feels like you can single out the different musicians or sounds.

As pointed out in other threads that isn't necessarily an accurate representation of a live event. In an intimate live event you can get a combination of auditory and visual cues as to where sound is coming from (you can see the tuba player, you can see the drummer), but the radiation of sound from those instruments are very different than from a speaker. But I still find a large, immersive soundstage to be very rewarding and captivating.

I guess some of you have noticed how music often sounds larger than life and somehow better in soundtracks of movies. There is some resemblance to that effect, but with 2-channel audio. I find it fascinating.
I go to concerts weekly, and for years I've closed my eyes and tried to localize the sound. Some of these places are quite live, and it can be kind of surprising what you notice when you turn off the visual stimuli. That sort of thing always bugged me at home, particularly with Magnepans. But at home you are trying to build a visual picture, not take it apart.

The new Geffen Hall is great at being live, but still pretty well localized (maybe too reverberant?). Lots of wood surfaces, none of them flat. Carnegie can give you quite a strong primary reflection from up and to the side of the stage if you are in the tiers.
 
Is it true that coaxials have a more precise but smaller soundstage than conventional speakers ?
In term of having less fake soundstage from widely seperated drivers in some large 3- or 4-way I would certainly say yes.
 

This test of imaging is interesting in that you can re-aim or reposition your speakers and effect where you hear things considerably. Proving it isn't just down to the speaker, but speaker positioning, aiming and your positioning within the room. I haven't done it recently, but one of the best results I ever obtained with this test signal is using QUAD-ESL 63's. A quasi-point source. I was rather far from them in a long room.
 
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