What makes speakers "disappear " and can it be measured?

[gsp1971]

This one is wonderful.
Not many can beat the Audio Physic Virgo II , Even today
https://www.stereophile.com/content/audio-physic-virgo-loudspeaker-measurements-part-3

how about this?
https://audio.com.pl/files/isv/1877-magico_s5.pdf

 

[R Swerdlow]

What makes speakers disappear is a complex topic. Others in this thread have already mentioned a number of individual features that can contribute to this. But there is no single feature that does this.

A number of years ago the late Jeff Bagby wrote about this, although he spoke of 'speaker imaging' instead of 'speakers disappearing'. I liked what he said well enough to save his comments (over a number of posts) as a single document.

 

[ferrellms]

I noticed that some speakers just disappear and it feels like the sound appears out of thin air, and others don't feel like that at all, and the sound is just coming out of 2 speakers.
What makes speakers "disappear" and can it be measured?

My Genelec 8040As "disappear" when I am seated properly between them and less than 6 feet away from them. Genelec wants us to pay attention to the ratio of direct to reflected sound from the monitors and recommends sitting close enough and using directional speakers to get more direct sound. They also recommend the "equilateral triangle" listening position between the speakers. Their larger speakers are more directional and louder and thus more suitable for larger rooms and further listening distances. I have a new, bigger room now and tried placing the 8040s as I would "hifi speakers" - far apart, away from walls and the listening position. Bad news, the image was all over the place. I now have them as positioned in my previous smaller room, against the wall, 6' apart and an equilateral triangle with the listening position despite the bigger room size, thus adhering to the Genelec recommendation on listening distance for the 8040 of around 6 feet or less. Moving to the 8351s will better fit the larger room due to increased volume headroom and increased directivity and will allow further listening distances and will allow the speakers to be farther apart, by about a foot or so, and still "disappear". See chart from Genelec.

In other words - following manufacturer recommendations and use of good gear will allow the system to "disappear".

 

[thewas]

Point source + minimum phase system = invisible speakers

Basically I guess this is it, when loudspeaker don't "disappear or image well, it is usually due to several close sound sources due to multiple spaced drivers, enclosure/baffle diffraction effects or early wall or other closes objects reflection.

That is also the reason why the imaging gets worse at higher listening distances as in the above posted Genelec distance recommendation chart, as the reflected sound dominates over the direct one.

 

[DHT 845]

In my experience pading the tweeter (in similar way as Wilson Audio does) helps in sound detachment. The pad may be cut out from the material used for scratch floor protectors.

 

[Plcamp]

In my experience pading the tweeter (in similar way as Wilson Audio does) helps in sound detachment. The pad may be cut out from the material used for scratch floor protectors.

View attachment 144122

Why not extend felt treatment to and around entire front baffle?

 

[DHT 845]

Why not extend felt treatment to and around entire front baffle?

I think that just for tweeter is most effective because of tweeter's directivity, and easy to try too...

 

[Thomas_A]

I started a similar thread on the subject, but found this one. The background is that there are stereo systems where the central phantom image (e.g. dialogue) tilts when you move closer to one speaker, and you hear sound from the speaker closest to you. In other systems, the central phantom image remains in the center regardless of seating position. Thus the speaker is invisible regardless of seating position.

The question is if the differences that make the two systems can be measured?

 

[tecnogadget]

I started a similar thread on the subject, but found this one. The background is that there are stereo systems where the central phantom image (e.g. dialogue) tilts when you move closer to one speaker, and you hear sound from the speaker closest to you. In other systems, the central phantom image remains in the center regardless of seating position. Thus the speaker is invisible regardless of seating position.

The question is if the differences that make the two systems can be measured?

You kind of can get to this result easily by a little bit of cheating...

Pairing the mains with a coaxial center channel, and the help of the miraculous Dolby Pro Logic II, which pretty much any AVR or sound procesor has, now rebranded as Dolby Surround Upmixer DSU.

Whoever has setup a proper multichanel system and tried this, will understand it.

 

[antennaguru]

We have wall mounted Anthony Gallo Acoustics Strada2 main speakers and matching subs in our mountain house, and the speakers totally disappear sonically. Wall proximity matters not, with a proper loudspeaker design.

 

[Pearljam5000]

In my experience pading the tweeter (in similar way as Wilson Audio does) helps in sound detachment. The pad may be cut out from the material used for scratch floor protectors.

View attachment 144122

Unfortunately that padding looks kind of cheap, especially on such an expensive speaker

 

[DHT 845]

If it looks cheap... I don't mind, I just presented the idea of sth. that make sense and works exactly in the area of disappearing act

 

[Balle Clorin]

how about this?
https://audio.com.pl/files/isv/1877-magico_s5.pdf

Yes, that is maybe one of them ,or may be not , I have not heard S5 , but it tok 25 years and 4 times more expensive (after inflation). But I am biased I never sold my Virgo, my father adopted it and will not give it back.

 

[Thomas_A]

You kind of can get to this result easily by a little bit of cheating...

Pairing the mains with a coaxial center channel, and the help of the miraculous Dolby Pro Logic II, which pretty much any AVR or sound procesor has, now rebranded as Dolby Surround Upmixer DSU.

Whoever has setup a proper multichanel system and tried this, will understand it.

Perhaps, but this is more related to stereo speakers, where there are two options as I see it. Either using speakers with narrow directivity and heavily toed-in can give this effect, but with low "envelope effect" However, the other end of the spectrum would also fit. A speaker with wide and even dispersion will give more reflections that reduce speaker position effect, giving much more envelope but a bit of more fuzziness. It will depend on the position of listener to the speakers and the ratio of reflected to direct sound contribution.

 

[tecnogadget]

Perhaps, but this is more related to stereo speakers, where there are two options as I see it. Either using speakers with narrow directivity and heavily toed-in can give this effect, but with low "envelope effect" However, the other end of the spectrum would also fit. A speaker with wide and even dispersion will give more reflections that reduce speaker position effect, giving much more envelope but a bit of more fuzziness. It will depend on the position of listener to the speakers and the ratio of reflected to direct sound contribution.

Regarding the heavily toe-in. Using the Extreme Toe as described in the attached paper, has been the only way I've been able to experience similar results as having a physical centre channel (meaning you move to the side extremes of listening position and still feel vocals comes from the phantom center). The very inherent principles of Stereophonic reproduction makes that regardless of the quality of a loudspeaker, you will always perceive the phantom channel drifting to one of the sides if you move off the center, and that's mostly because how the music itself is mixed, if the recording engineer decided to ad panning, phase shift between channels, etc. A better speaker setup will lessen this, but not completely fix it.

 

[Jim Matthews]

A number of years ago the late Jeff Bagby wrote about this, although he spoke of 'speaker imaging' instead of 'speakers disappearing'. I liked what he said well enough to save his comments (over a number of posts) as a single document.

That's a keeper.

Kudos

 

[Thomas_A]

Regarding the heavily toe-in. Using the Extreme Toe as described in the attached paper, has been the only way I've been able to experience similar results as having a physical centre channel (meaning you move to the side extremes of listening position and still feel vocals comes from the phantom center). The very inherent principles of Stereophonic reproduction makes that regardless of the quality of a loudspeaker, you will always perceive the phantom channel drifting to one of the sides if you move off the center, and that's mostly because how the music itself is mixed, if the recording engineer decided to ad panning, phase shift between channels, etc. A better speaker setup will lessen this, but not completely fix it.

The interesting question is whether there is any way to measure the effect of phantom source position, i.e. taking speaker measurements to the "next level"?

 

[Jim Matthews]

Imaging with the current crop of transducers is noticeably better than just 10 years ago. I believe the inestimable Tom Danley considered polar response of all drivers the harshest filter : get that right and you have a chance to sum data in a convincing presentation.

Active amplification to reduce phase errors and timing delays *really* simplifies the crossover challenges between drivers.

Prior to my current 708p rig (home playback only - not a pro mixer) the most "realistic" imaging I could achieve was with crossoverless dipoles.
(Quad ESL63 and Bastanis wideband OB)

The controlled directivity of the 708p and digital crossover filters make for a tidy soundfield, without much fuss.

 

[Jim Matthews]

The interesting question is whether there is any way to measure the effect of phantom source position, i.e. taking speaker measurements to the "next level"?

This would vary between rooms, I should think.

Anechoic testing would only reveal diffraction effects, or cabinet resonance.


I suppose you could take binaural measurements and compare test tone delay? Anything greater than the time it takes a pulse to travel between the two mics would represent reflections from room boundaries.

I can't see how it would tease out timing errors between drivers, although polar response should illustrate that.

(I'll stop now, before I hurt myself.)

 

[Thomas_A]

This would vary between rooms, I should think.

Anechoic testing would only reveal diffraction effects, or cabinet resonance.


I suppose you could take binaural measurements and compare test tone delay? Anything greater than the time it takes a pulse to travel between the two mics would represent reflections from room boundaries.

I can't see how it would tease out timing errors between drivers, although polar response should illustrate that.

(I'll stop now, before I hurt myself.)

I would be specific for the speakers setup in that said room, but it would be (really) nice if there is a way (binaural recording, dummy head?) to get an output where you can visualize/plot the phantom source position of a center mono signal at different listening positions.

I have never seen this however.