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May I ask why a wide dispersion speaker is preferred?

whazzup

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#21
The way I understand this (pls feel free to correct), is that wide dispersion = minimal difference, or consistent roll-off, between on-axis / off-axis response.

Given how sound travels so fast, in most rooms, the off-axis reflected sound is a significant portion of the final sound that reaches the listener, even if toed-in. So if the off-axis frequency response of a set of speakers is 'lumpy' and inconsistent compared to its on-axis response, the final 'combined' sound might not be as good/consistent as another pair of speakers with even / smooth / wide dispersion characteristics.

edit: maybe I'm saying, it's about wide dispersion AND consistent roll-off that people largely preferred?
 
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RayDunzl

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#22

Sir Sanders Zingmore

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#23
The way I understand this (pls feel free to correct), is that wide dispersion = minimal difference, or consistent roll-off, between on-axis / off-axis response.

Given how sound travels so fast, in most rooms, the off-axis reflected sound is a significant portion of the final sound that reaches the listener, even if toed-in. So if the off-axis frequency response of a set of speakers is 'lumpy' and inconsistent compared to its on-axis response, the final 'combined' sound might not be as good/consistent as another pair of speakers with even / smooth / wide dispersion characteristics.

edit: maybe I'm saying, it's about wide dispersion AND consistent roll-off that people largely preferred?
This is my understanding too. The sound that reaches you at the listening position is the combination of direct sound from the speakers and reflected sound. You want both of these sounds to sound the same (in other words the off-axis sounds from the speaker should have the same frequency response as the direct sound).

The above is true for non-beaming speakers. My experience of beaming speakers (Sanders electrostats) is that instead of trying to make off-axis sounds have the same FR as on-axis, they try to make off-axis sounds disappear as much as possible. The theory being that the level of off-axis sounds reaching you from a beaming speaker should be so low as to be irrelevant
 
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JungleXray
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Thread Starter #24
This is my understanding too. The sound that reaches you at the listening position is the combination of direct sound from the speakers and reflected sound. You want both of these sounds to sound the same (in other words the off-axis sounds from the speaker should have the same frequency response as the direct sound).

The above is true for non-beaming speakers. My experience of beaming speakers (Sanders electrostats) is that instead of trying to make off-axis sounds have the same FR as on-axis, they try to make off-axis sounds disappear as much as possible. The theory being that the level of off-axis sounds reaching you from a beaming speaker should be so low as to be irrelevant
That’s got be be the best explanation Ive read.
 

Bjorn

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#25
One needs to take into the account at what time the side wall reflections arrive and the general acoustics of the room besides the polar response of the speaker. Without looking at this, conclusions of what's better or preferred ends up being quite meaningsless.

Example: A side wall reflection which arrives 2-5 ms after the direct sound is audiblly very different from a side wall reflection arrving after 10-12 ms or later. Very early reflections have much more negative impact on several areas compared to much later ones. There are no indications that very early reflections are beneficial in any way.

Also. If a room can be treated acoustically, it's possible to achieve spaciousness without reflective side walls. This is an area which Toole never researched but many other have studied the effect of acoustic treatment. Obviously few can treat a room extensively at their home, but we do see more and more audiophiles using acoustic treatment.

Needless to say, the speaker needs to exhibit a uniform horizontal directivity over the most sensitive area if later side wall reflections should be used.

Personally I've found out that most have rooms and acoustics that would benefit from a speaker with narrow directivity both horizontally and vertically, but the mileage may vary depending on the mentioned room layout as well as whether the person only listens at one spot or also wants a speaker that sounds great around the room.
 

Chromatischism

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#26
People want wide dispersion.

Then a whole new industry is spawned to reduce or otherwise dissipate the reflections.

acoustic absorbers and diffusers

View attachment 81164
They are needed in some rooms but great care must be taken since they EQ your sound. If only people knew that absorbers are another form of directivity control, and a well-designed speaker does a much better job of that since it controls the entire bandwidth evenly.
 
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#27
Statements like "wider is preferred" are meaningless. Depends on a lot factors. Room acoustics, speaker placement, speaker toe in, listener placement, distance from speaker and listener to each wall for early reflections, music genre, etc.

For my room I only need the dispersion to be wide enough to cover the listening window. Any more than that and it is only doing harm. My room is tiny compared to music performance space. I don't want it to interfere with early reflections.
 

Chromatischism

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#28
Statements like "wider is preferred" are meaningless. Depends on a lot factors. Room acoustics, speaker placement, speaker toe in, listener placement, distance from speaker and listener to each wall for early reflections, music genre, etc.

For my room I only need the dispersion to be wide enough to cover the listening window. Any more than that and it is only doing harm. My room is tiny compared to music performance space. I don't want it to interfere with early reflections.
Maybe in our small rooms, we could try minimizing early reflections, and going for late reflections to make the room sound bigger.

That would imply a steep toe-in with speakers with very good off-axis performance, no absorption, and using more diffusion toward the back half of the room. What do you think?
 

Wombat

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#29
It is all about preference. I don't like the off-the-wall of sound to be too apparent. Others do. I don't like a pin-head sweet-spot. Others do.

Talking about pin-head sweet-spot, time to restore the avatar. o_O

5462 - Copy.jpg
 

napilopez

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#30
It seems to me that here on this forum most agree that a speaker with a wide dispersion pattern is a good thing. Why is this? If one was to do their stereo listening from the same spot (like a listening chair), and have the speaker toed in to be facing them, wouldn't a wide dispersion pattern be... sort of wasted?

Also lets say that in this hypothetical listening room that one speaker is near a corner. A foot away we will say. Wouldn't having a wide dispersion create an early reflection problem? A problem that a more narrow beaming speaker would not have.

A wide dispersion pattern does not equal a wide sound stage right? If you had a beaming speaker pointed right at the you listening on axis would this not give the best imaging? The best frequency response?

I only can see two problems with a beaming speaker. Having you "head in a vice" is one problem. Maybe you don't want to sit static is one position to get the best out of your speakers. The other is if you wanted to listen with another person. If they were sitting next to you they would not get the same imaging and frequency response. (This is not a problem for me as all my friends think I am an A hole for the money I spent on my system )

So, why is it wide dispersion is preferred?
So you are talking about a few different things here. Wide directivity speakers can have a wider sweetspot, but not necessarily. Placement and toe in can make a narrow-directivity speaker have just as wide a sweet spot, and in some cases even wider.

But you asked "a wide directivity speaker does not equal a wide soundstage right?" Actually, that is quite literally the primary effect of a wide directivity speaker, all else being equal.

To oversimplify and generalize, let's imagine two pairs of speakers that are identical in every regard except for dispersion, placed in a good room. One has rather wide directivity, one has rather narrow directivty. The narrower speaker will have more pin-point imaging, in which sources appear more focused. You can pick out exactly where each sound is coming from. You could probably point to the sources with a laser.

But the wider directivity speaker will sound, well, wider. Hard-panned instruments are less likely to sound like they are coming directly from your speakers and may instead seem to occupy the space between your speakers and your walls. The soundstage and instruments appear larger than on the narrower design. But as a consequence, the image may appear 'fuzzier' and you may lose some of that pinpoint instrument placement.

The reason why is fairly intuitive once you understand that our brains use information from both the direct and early reflected sound to create our impression of music

With wider horizontal directivity, you get louder sidewall reflections. Though the direct sound is still dominant, your brain allows the sidewall reflections to contribute information about the sound as long as they are not delayed by too long. As a result the image gets broader and/or shifts in the direction of the reflection. So wide directivity quite literally equates to a wider soundstage in most cases.

It might help to think of the opposite scenario. The narrowest directivity speakers are headphones. Without reflections, it's hard for the sound to feel particularly spacious. For the same reason, I've often heard listening to speakers in an anechoic chamber (again, no sidewall reflections) described as being somewhat akin to wearing open back headphones.

However, it's not black and white, as things can vary depending on the recording and room acoustics. Some recordings contain a lot of spatial information already, for instance, or use special tricks to provide a wider soundstage.

Research into both sidewall reflections(in the context of room treatment) and the directivity of speakers seems to suggest that the presence of louder sidewall reflections is generally preferred.

But this should not be conflated with the idea that wide directivity is *always* a good thing, in the way aiming for a flattish frequency response is pretty much always good. Some people have a strong preference for a narrow sound, and there is nothing wrong with designing a narrower speaker. It can also be handy for dealing with particularly bad room acoustics.

Blue is overwhelmingly the world's favorite color, but plenty of people much prefer red.

Also keep in mind the discussion is more useful in a comparative sense. Most mainstream speakers aren't extremely wide or narrow, after all, so it's best to compare on a case by case basis. In the real world, there are no completely identical speakers with different directivities, so you have to figure out your own tastes.
 
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Wombat

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#31
So you are talking about a few different things here. Wide directivity speakers can have a wider sweetspot, but not necessarily. Placement and toe in can make a narrow-directivity speaker have just as wide a sweet spot, and in some cases even wider.

But you asked "a wide directivity speaker does not equal a wide soundstage right?" Actually, that is quite literally the primary effect of a wide directivity speaker, all else being equal.

To oversimplify and generalize, let's imagine two pairs of speakers that are identical in every regard except for dispersion, placed in a good room. One has rather wide directivity, one has rather narrow directivty. The narrower speaker will have more pin-point imaging, in which sources appear more focused. You can pick out exactly where each sound is coming from. You could probably point to the sources with a laser.

But the wider directivity speaker will sound, well, wider. Hard-panned instruments are less likely to sound like they are coming directly from your speakers and may instead seem to occupy the space between your speakers and your walls. The soundstage and instruments appear larger than on the narrower design. But as a consequence, the image may appear 'fuzzier' and you may lose some of that pinpoint instrument placement.

The reason why is fairly intuitive once you understand that our brains use information from both the direct and early reflected sound to create our impression of music

With wider horizontal directivity, you get louder sidewall reflections. Though the direct sound is still dominant, your brain allows the sidewall reflections to contribute information about the sound as long as they are not delayed by too long. As a result the image gets broader and/or shifts in the direction of the reflection. So wide directivity quite literally equates to a wider soundstage in most cases.

It might help to think of the opposite scenario. The narrowest directivity speakers are headphones. Without reflections, it's hard for the sound to feel particularly spacious. For the same reason, I've often heard listening to speakers in an anechoic chamber (again, no sidewall reflections) described as being somewhat akin to wearing open back headphones.

However, it's not black and white, as things can vary depending on the recording and room acoustics. Some recordings contain a lot of spatial information already, for instance, or use special tricks to provide a wider soundstage.

Research into both sidewall reflections(in the context of room treatment) and the directivity of speakers seems to suggest that the presence of louder sidewall reflections is generally preferred.

But this should not be conflated with the fact the idea that wide directivity is *always* a good thing, in the way aiming for a flattish frequency response is pretty much always good . Some people have a strong preference for a narrow sound, and there is nothing wrong with designing a narrower speaker. It can also be handy for dealing with particularly bad room acoustics.

Blue is overwhelmingly the world's favorite color, but plenty of people much prefer red.

Also keep in mind the discussion is more useful in a comparative sense. Most mainstream speakers aren't extremely wide or narrow, after all, so it's best to compare on a case by case basis. In the real world, there are no completely identical speakers with different directivities, so you have to figure out your own tastes.

Most people cannot try a range of products, in home, before buying. This seems to be an option in the USA but eventually freight and restocking charges are limiting.
 
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Chromatischism

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#33
To oversimplify and generalize, let's imagine two pairs of speakers that are identical in every regard except for dispersion, placed in a good room. One has rather wide directivity, one has rather narrow directivty. The narrower speaker will have more pin-point imaging, in which sources appear more focused. You can pick out exactly where each sound is coming from. You could probably point to the sources with a laser.

But the wider directivity speaker will sound, well, wider. Hard-panned instruments are less likely to sound like they are coming directly from your speakers and may instead seem to occupy the space between your speakers and your walls. The soundstage and instruments appear larger than on the narrower design. But as a consequence, the image may appear 'fuzzier' and you may lose some of that pinpoint instrument placement.
I was experimenting with this recently with my S400s, which fall somewhere in between. This speaker can produce either scenario depending on placement and toe angle. The difference is so striking that it can sound like a different speaker.

I seem to enjoy the laser-like imaging of the speakers pointed right at me, but not the fact that the speakers no longer disappear and that things sound much more direct and forward. On the other hand, I seem to enjoy the more dreamy soundstage produced when the speakers cross behind me. The tradeoff is that the imaging gets a little more diffuse, as you say. I have yet to try crossing in front of me, but it's possible that could get me the best of both.
 

napilopez

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#34
I was experimenting with this recently with my S400s, which fall somewhere in between. This speaker can produce either scenario depending on placement and toe angle. The difference is so striking that it can sound like a different speaker.

I seem to enjoy the laser-like imaging of the speakers pointed right at me, but not the fact that the speakers no longer disappear and that things sound much more direct and forward. On the other hand, I seem to enjoy the more dreamy soundstage produced when the speakers cross behind me. The tradeoff is that the imaging gets a little more diffuse, as you say. I have yet to try crossing in front of me, but it's possible that could get me the best of both.
Yes, the S400/A500 have some of the widest sweet spots I've heard. The sound barely changes in the measurements all the way out to 30 degrees. This is in part thanks to the combination of a smaller than usual tweeter and the waveguide.

Keep in mind though that crossing in front of you does not necessarily provide a larger soundstage, it only widens the sweetspot. I actually think it tends to compress the soundstage in width a bit, while sometimes sounding more diffuse. Which would make sense: your right speaker gets shifted leftward and vice versa. But it can work wonders for widening the sweet spot indeed.
 

Chromatischism

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#35
Yes, the S400/A500 have some of the widest sweet spots I've heard. The sound barely changes in the measurements all the way out to 30 degrees. This is in part thanks to the combination of a smaller than usual tweeter and the waveguide.

Keep in mind though that crossing in front of you does not necessarily provide a larger soundstage, it only widens the sweetspot. I actually think it tends to compress the soundstage in width a bit, while sometimes sounding more diffuse. Which would make sense: your right speaker gets shifted leftward and vice versa. But it can work wonders for widening the sweet spot indeed.
Yeah, it's worth experimenting with at least. I want both imaging and soundstage but understand it's a compromise, like most things in audio.
 

RayDunzl

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#36
Yes, the S400/A500 have some of the widest sweet spots I've heard. The sound barely changes in the measurements all the way out to 30 degrees.
Please show those measurements, of a stereo pair, at center, as well as at the boundaries of that wide sweetspot.
 

MattHooper

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#37
I have been able to enjoy some narrow dispersion speakers but, all else being equal, I prefer that a speaker have a wide sweet spot in terms of wide and even enough dispersion such that I don't have the "head in the vice" sensation. If a speaker's imaging and tonal quality obviously shift with minor movements I find it can be a bit distracting and it feels less natural. It reminds me of the difference between the old rear projection TVs and many LCD screens and emissive displays like plasma and OLED and CRT. The rear projection TV lens/screen system meant you had to have a position directly in front and with any position off center or movement, I could see the image degrade, having a "shifty" quality. I get the same discomfort from a speaker that is "too" directional. It's another reason I gave up on ESLs as well. (Though I can certainly appreciate the sound in the sweetspot).
 

Chromatischism

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#38
I have been able to enjoy some narrow dispersion speakers but, all else being equal, I prefer that a speaker have a wide sweet spot in terms of wide and even enough dispersion such that I don't have the "head in the vice" sensation. If a speaker's imaging and tonal quality obviously shift with minor movements I find it can be a bit distracting and it feels less natural. It reminds me of the difference between the old rear projection TVs and many LCD screens and emissive displays like plasma and OLED and CRT. The rear projection TV lens/screen system meant you had to have a position directly in front and with any position off center or movement, I could see the image degrade, having a "shifty" quality. I get the same discomfort from a speaker that is "too" directional. It's another reason I gave up on ESLs as well. (Though I can certainly appreciate the sound in the sweetspot).
Check out Part 3 of this series (the first two are worth watching, too):

 

richard12511

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#39
Check out Part 3 of this series (the first two are worth watching, too):

Yeah, if you can stand the looks of extreme toe in, narrow dispersion actually has a wider sweet spot. Figuring that out was a game changer for me, and I've gotten use to the looks. This only works horizontally, though; the sound of my JTRs still changes a lot more than my Revels when I stand up, which is a definite weakness.

I've yet to hear the new Buchardt offerings, but I really want to.
 

TimF

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