Speakers for imperfect listening positions

[ta240]

I'm wondering what I should look for in speakers for a room where I really won't ever be sitting in the 'sweet spot'. Sometimes I'll be sitting to one side or the other (pretty much directly in front of a speaker, but 8' or so back). Sometimes I'll be on the floor below the speakers and up closer to them. Etc.
On one side the speaker will be about 4 feet from a side wall and on the other there isn't a side wall.
I'm not expecting the perfect stereo experience all over the room but I have found that some do a better job of not sounding like I'm just hearing the one speaker in front of me.

 

[Penelinfi]

 

[Duke]

I'm wondering what I should look for in speakers for a room where I really won't ever be sitting in the 'sweet spot'. Sometimes I'll be sitting to one side or the other (pretty much directly in front of a speaker, but 8' or so back). Sometimes I'll be on the floor below the speakers and up closer to them. Etc.
On one side the speaker will be about 4 feet from a side wall and on the other there isn't a side wall.
I'm not expecting the perfect stereo experience all over the room but I have found that some do a better job of not sounding like I'm just hearing the one speaker in front of me.

Imo there is a solution.

Here is some background for what I'm about to suggest: The ear determines the direction of a sound source by two mechanisms - arrival time, and intensity. If a sound arrives at the same time from both speakers but is louder from one of the speakers, the image location will be pulled towards the louder speaker. If the loudness is the same from both speakers but the sound arrives earlier from one of them, the image location will be pulled towards the first-arrival speaker.

There is a clever (though somewhat counter-intuitive) way to exploit this characteristic of human hearing to increase the width of the listening area within which you get a good soundstage.

The technique is called "time/intensity trading". You'd use a pair of speakers with a fairly narrow and well-behaved radiation pattern and toe them in aggressively such that their axes criss-cross in front of the normal central "sweet spot". The situation from well off to one side of the centerline is this: The listener is very far off-axis of the near speaker, but on-axis, or nearly so, of the far speaker. So the output of the near speaker arrives FIRST, but the output of the far speaker is LOUDER. The net result is that the two localization mechanisms (arrival time and intensity) approximately cancel one another out, so we still have a pretty good spread of the instruments in between the speakers, with the center vocalist roughly in the center. The image locations are not as precise as from listening locations up and down the centerline, but the imaging is still enjoyable.

The SECRET to time/intensity trading being successful is this: The output from the near speaker must fall off SMOOTHLY and RAPIDLY as the listener moves off-axis. In my experience time/intensity trading does not work well with conventional speakers; their radiation patterns are too wide and usually have too much variation, such that timbre is degraded at locations well off-axis.

Credit to Earl Geddes for teaching me the technique. I've been using it for more than twenty years.

If you'd like a visual, here's one such set-up. Underneath the grilles are waveguide-style horns with a 90 degree pattern width in the horizontal plane, crossed over to 12" woofers where their radiation patterns match (about 1.5 kHz). From the location where this photo was taken, with eyes closed the dialogue comes from onscreen (there is no center-channel speaker behind the screen). Note how we're approximately on-axis of the far speaker, but well off-axis of the near speaker:

 

[boxerfan88]

Here is some background for what I'm about to suggest: The ear determines the direction of a sound source by two mechanisms - arrival time, and intensity. If a sound arrives at the same time from both speakers but is louder from one of the speakers, the image location will be pulled towards the louder speaker. If the loudness is the same from both speakers but the sound arrives earlier from one of them, the image location will be pulled towards the first-arrival speaker.

There is a clever (though somewhat counter-intuitive) way to exploit this characteristic of human hearing to increase the width of the listening area within which you get a good soundstage.

The technique is called "time/intensity trading". You'd use a pair of speakers with a fairly narrow and well-behaved radiation pattern and toe them in aggressively such that their axes criss-cross in front of the normal central "sweet spot". The situation from well off to one side of the centerline is this: The listener is very far off-axis of the near speaker, but on-axis, or nearly so, of the far speaker. So the output of the near speaker arrives FIRST, but the output of the far speaker is LOUDER. The net result is that the two localization mechanisms (arrival time and intensity) approximately cancel one another out, so we still have a pretty good spread of the instruments in between the speakers, with the center vocalist roughly in the center. The image locations are not as precise as from listening locations up and down the centerline, but the imaging is still enjoyable.

The SECRET to time/intensity trading being successful is this: The output from the near speaker must fall off SMOOTHLY and RAPIDLY as the listener moves off-axis. In my experience time/intensity trading does not work well with conventional speakers; their radiation patterns are too wide and usually have too much variation, such that timbre is degraded at locations well off-axis.

Several years ago, I was told about this method by a Tannoy owner. It works really well for his Tannoy setup. It's actually documented in the Tannoy manual.

 

[boxerfan88]

I'm wondering what I should look for in speakers for a room where I really won't ever be sitting in the 'sweet spot'. Sometimes I'll be sitting to one side or the other (pretty much directly in front of a speaker, but 8' or so back). Sometimes I'll be on the floor below the speakers and up closer to them. Etc.
On one side the speaker will be about 4 feet from a side wall and on the other there isn't a side wall.
I'm not expecting the perfect stereo experience all over the room but I have found that some do a better job of not sounding like I'm just hearing the one speaker in front of me.

My suggestion is to look for wide dispersion speakers. That are coaxial even better.

 

[hashhar]

How to identify a speaker is wide dispersion or not? What measurements to look at?

By wide dispersion do you mean the SPL Contour measurements which show how the SPL various on the horizontal and vertical axes?

 

[boxerfan88]

How to identify a speaker is wide dispersion or not? What measurements to look at?

By wide dispersion do you mean the SPL Contour measurements which show how the SPL various on the horizontal and vertical axes?

Yeap, look at the contour plot for wide dispersion >45 degrees , and even across most of the audio band.

For example:

Measurements for speaker Genelec 8351B

www.spinorama.org

Spinorama site is a good resource.

 

[diablo]

You could use a MiniDSP Flex with either Dirac or REW setup to adjust timings, levels and frequency response for upto four positions.

In my lounge I have just two main seating positions. One is directly in front of the speakers, where the speakers are an equal distance from me. But the other is way off to the side, Though as I type I am still enjoying a balanced centred sound stage from the outer speakers in this pic, taken from where I'm now sat -

 

[audiofooled]

Imo there is a solution.

Here is some background for what I'm about to suggest: The ear determines the direction of a sound source by two mechanisms - arrival time, and intensity. If a sound arrives at the same time from both speakers but is louder from one of the speakers, the image location will be pulled towards the louder speaker. If the loudness is the same from both speakers but the sound arrives earlier from one of them, the image location will be pulled towards the first-arrival speaker.

There is a clever (though somewhat counter-intuitive) way to exploit this characteristic of human hearing to increase the width of the listening area within which you get a good soundstage.

The technique is called "time/intensity trading". You'd use a pair of speakers with a fairly narrow and well-behaved radiation pattern and toe them in aggressively such that their axes criss-cross in front of the normal central "sweet spot". The situation from well off to one side of the centerline is this: The listener is very far off-axis of the near speaker, but on-axis, or nearly so, of the far speaker. So the output of the near speaker arrives FIRST, but the output of the far speaker is LOUDER. The net result is that the two localization mechanisms (arrival time and intensity) approximately cancel one another out, so we still have a pretty good spread of the instruments in between the speakers, with the center vocalist roughly in the center. The image locations are not as precise as from listening locations up and down the centerline, but the imaging is still enjoyable.

The SECRET to time/intensity trading being successful is this: The output from the near speaker must fall off SMOOTHLY and RAPIDLY as the listener moves off-axis. In my experience time/intensity trading does not work well with conventional speakers; their radiation patterns are too wide and usually have too much variation, such that timbre is degraded at locations well off-axis.

Credit to Earl Geddes for teaching me the technique. I've been using it for more than twenty years.

If you'd like a visual, here's one such set-up. Underneath the grilles are waveguide-style horns with a 90 degree pattern width in the horizontal plane, crossed over to 12" woofers where their radiation patterns match (about 1.5 kHz). From the location where this photo was taken, with eyes closed the dialogue comes from onscreen (there is no center-channel speaker behind the screen). Note how we're approximately on-axis of the far speaker, but well off-axis of the near speaker:


View attachment 426890

This has been my experience too. It requires loudspeakers of specific (very tight) radiation pattern control and time domain performance, also some setup precision (room placement, toe in angle and spacing). It doesn't sound natural with speakers that are optimized to work well only directly on axis though.

 

[gnarly]

View attachment 426869
View attachment 426870

+100

Use speakers that dramatically Increase the ratio of reflected sound to direct sound.
Like the above, or to use a more well known example, Bose 901's with its one forward facing driver pointed outward, and its eight 8 rear drivers pointing into a back wall.

Much more effective than conventional speaker aiming strategies, or using dipoles, etc.
Swamp direct with reflected.

 

[Timcognito]

This a review with some measurements of the Larsen 4.2 ($2,400 at that time). The Larsen's which go up to the most expensive Larsen 9 have had many positive reviews on different models. The design supports stereo sound in all parts of the room with some sacrifice in precise imaging but is adaptable any room with an open wall as they go up against and use it, also saving floor space. The reviewer does a good job of explaining it.

 

[berjine]

A technique that I really like is to use 4 speakers at each corner of the room (or as best as you can depending on the shape of your room), with the R and L channels crossed such that you have R and L on each side of the quadrangle

Your brain will always focus on the two closest speakers, so you will have some imaging over a much greater area than with just 2 speakers

Another benefit is that the global volume can be lower while still having an enjoyable sound, so it's perfect for casual listening (with 2 speakers I easily feel too close or too far from the speakers, the confort zone of quad is much bigger)

 

[Duke]

A technique that I really like is to use 4 speakers at each corner of the room (or as best as you can depending on the shape of your room), with the R and L channels crossed such that you have R and L on each side of the quadrangle

Your brain will always focus on the two closest speakers, so you will have some imaging over a much greater area than with just 2 speakers

Another benefit is that the global volume can be lower while still having an enjoyable sound, so it's perfect for casual listening (with 2 speakers I easily feel too close or too far from the speakers, the confort zone of quad is much bigger)

Very clever and creative idea! I like it!

 

[berjine]

Thanks ! From my experience it works especially great when the speakers are placed high, because then you stay further from them and the illusion works longer as you get closer to the corner. I used Tannoy speakers for this, the symmetric radiation of the coax certainly helped for having a consistent sound

I think this solution is particularly useful in a space-constrained situation, otherwise if you have enough space to place speakers far from the walls then omni/dipole/backwards speakers should certainly work very well !

 

[janbth]

A technique that I really like is to use 4 speakers at each corner of the room (or as best as you can depending on the shape of your room), with the R and L channels crossed such that you have R and L on each side of the quadrangle

Sorry, I didn’t get this. Could you show a diagram, please?

 

[berjine]

Sorry, I didn’t get this. Could you show a diagram, please?

Sure !

 

[janbth]

Sure !

View attachment 427258

Ah, thanks, I get it now! Very interesting setup!

 

[Fred H]

I'm wondering what I should look for in speakers for a room where I really won't ever be sitting in the 'sweet spot'.

I bought Ohm Walsh speakers for exactly that reason. My wife reclines on a sofa outside the right speaker and has full stereo.

 

[Duke]

The benefit to off-centerline listeners of a good time/intensity trading setup is that it does a good job of offsetting the earlier arrival time of the near speaker with louder sound from the far speaker. A system using omnis still will tend to image-shift towards the first-arrival speaker because there is nothing to offset that. The shift is not as bad as with conventional speakers.

When you do move back to the sweet spot, a good time/intensity trading configuration offers imaging competitive with (and in some ways arguably superior to) a good conventional configuration, so it's not like you're trading off good imaging in the sweet spot for the sake of off-centerline imaging.

 

[Chr1]

Thanks ! From my experience it works especially great when the speakers are placed high, because then you stay further from them and the illusion works longer as you get closer to the corner. I used Tannoy speakers for this, the symmetric radiation of the coax certainly helped for having a consistent sound

I think this solution is particularly useful in a space-constrained situation, otherwise if you have enough space to place speakers far from the walls then omni/dipole/backwards speakers should certainly work very well !

Thank you for this suggestion.

I am planning to do this not too long from now.

4 x Tannoy V12s hung from yokes. Plus subs.