I searched and couldn't find anything related to the optimal listening point of a stereo system and how it can be narrowed or widened to a significant area. Although the subject seems very widely debated, concrete information is few and mixed with a lot of irrelevant information.
What interests me is how the filters (or other details from the speaker) can influence this aspect, how you can use the filters to obtain an optimal audition in a single point or a very wide one.
If there are already these debated things, please direct me to that place.
I mention that I have already read the first topics suggested when I created this topic and I did not find the desired information.
What interests me is how the filters (or other details from the speaker) can influence this aspect, how you can use the filters to obtain an optimal audition in a single point or a very wide one.
If there are already these debated things, please direct me to that place.
I mention that I have already read the first topics suggested when I created this topic and I did not find the desired information.
Martin logan electrostatics...i listened to some in 2015 ...stereo image everywhere in the room...
Constant directivity is very effective at making a wider sweetspot. You cross-fire the axes for maximum effect (heavy toe-in), meaning the speakers "point" to a point in front of you, rather than a point behind you as is more typical (mild toe-in).
The JBL Everest DD55000 used an unusual horn to give a good sweet spot across the listening area. Toed in correctly as you move from left to right the spl from each speaker remains similar to keep the image balanced. Worth a read up, the car audio chaps use a similar theory by fitting tweeters in the A pillars and firing across the car towards the B pillar on the opposite side (I did this on one of my cars and it worked extremely well)
Rob.
Rob.
Hi,
https://www.pispeakers.com/Pi_Speakers_Info.pdf
What Badman pointed.
Diyiggy,
I kinda agree mtm can give this kind of feeling. Coax drivers can gives this feeling too ( until you start to notice phantom image issue...).
Could you explain your thoughts about 'how its filtered'?
https://www.pispeakers.com/Pi_Speakers_Info.pdf
What Badman pointed.
Diyiggy,
I kinda agree mtm can give this kind of feeling. Coax drivers can gives this feeling too ( until you start to notice phantom image issue...).
Could you explain your thoughts about 'how its filtered'?
Yeah there is many levels to sweet spot size and many things affect. For example beaming highs, toe in needs to be right to get smooth response. Hopefully speaker is acoustically good so that the good response is wider than 1-5 degrees, much wider, so more than one ear receives nice direct sound. Then, move the whole setup so that bass response is good at listening spot, due to room modes. Are the speakers now near walls / asymmetrically positioned, perhaps too much coloration due to bad off-axis response? Better speakers and acoustic treatment to help. Left and right responses matched within 1db? DSP if not. Both the speakers and room affect on things at the sweetspot.
Now that one has worked on some of the most audible things quite far, further than most people, you'll notice the sweetspot is still kind of small because of two speakers and two ears. If head moves from exact sweetspot the comb filter is easy to hear, each ear hears both speakers, path length difference makes comb filter as soon as one deviates form exact center. Although sound in room is nice the comb filtering makes the sweet spot kind of small still, and nothings gonna rescue from this but dedicated center speaker to get rid of phantom center.
So, its running in circles anyway if one has two speakers. Use one or three for bigger sweet spot, with all tricks above. Perhaps there is even more tricks. I love single speaker mono. Also two speaker stereo is nice despite the phantom image "issues", which I think is kind of the salt of stereo listening. Makes the sound kind of there but not quite, almost touchable but still unreachable, somehow its a nice feeling and elevates the music to something magical 🙂 Never tried three speaker stereo, gonna try one day.
Now that one has worked on some of the most audible things quite far, further than most people, you'll notice the sweetspot is still kind of small because of two speakers and two ears. If head moves from exact sweetspot the comb filter is easy to hear, each ear hears both speakers, path length difference makes comb filter as soon as one deviates form exact center. Although sound in room is nice the comb filtering makes the sweet spot kind of small still, and nothings gonna rescue from this but dedicated center speaker to get rid of phantom center.
So, its running in circles anyway if one has two speakers. Use one or three for bigger sweet spot, with all tricks above. Perhaps there is even more tricks. I love single speaker mono. Also two speaker stereo is nice despite the phantom image "issues", which I think is kind of the salt of stereo listening. Makes the sound kind of there but not quite, almost touchable but still unreachable, somehow its a nice feeling and elevates the music to something magical 🙂 Never tried three speaker stereo, gonna try one day.
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I tend to get wider soundstage and imaging effects with increased pressure off-axis left of left ear and right of right ear: typically with the speakers moved closer together and with some amount of "toe-out" or horizontal rotation away from the listener (often "firing" straight ahead in-room), and relative to listening closer to the loudpeakers (..typically speakers about 7-8 feet apart and the listener about 6 feet from the loudspeakers assuming the loudspeaker design has a good dispersion and diffraction profile to allow this). With enough pressure difference and with the right recording, imaging left of left speaker and right of right speaker occurs easily.
I also tend to hear a wider "spread" with *tube push-pull amplifiers for whatever reason (though often with a bit less apparent depth than single-ended).
*often a "house sound" for Acoustic Research amplifiers.
I don't tend to hear it with different filters (..unless of course the filter also improves resulting apparent depth).
Finally, low-freq. ambient effects (real or processed) also tend to increase the overall "size" of the soundstage which of course increases stage width.
..other than the above,
Image width (acoustic source width) can be widened with near level/intensity far reflections (contralateral reflections), or very close in time and intensity near reflections (lateral reflections).. but it's sort of a "smearing" result. This effect in acoustics is usually considered very desirable: it makes instruments and vocals sound "bigger". It can also be achieved to some extent with diffraction from large width (poorly radius-ed) baffles and particularly large horns, but at the likely compromise of localizing the speakers (to some extent) which is often a bit ameliorated with further listening distance (which in itself ALSO increases Image width by increasing the room's side-wall reflections relative to direct sound as already noted).
As for increasing the listening AREA for width (multi-listener or lateral moving listener): that's usually just a matter of horizontal dispersion. A wide (like 50 degrees +/-) uniform horizontal dispersion from 1 kHz up to about 7 kHz does this pretty well. Lower diffraction effects a bit lower than this range tend to make the result more clear.
I also tend to hear a wider "spread" with *tube push-pull amplifiers for whatever reason (though often with a bit less apparent depth than single-ended).
*often a "house sound" for Acoustic Research amplifiers.
I don't tend to hear it with different filters (..unless of course the filter also improves resulting apparent depth).
Finally, low-freq. ambient effects (real or processed) also tend to increase the overall "size" of the soundstage which of course increases stage width.
..other than the above,
Image width (acoustic source width) can be widened with near level/intensity far reflections (contralateral reflections), or very close in time and intensity near reflections (lateral reflections).. but it's sort of a "smearing" result. This effect in acoustics is usually considered very desirable: it makes instruments and vocals sound "bigger". It can also be achieved to some extent with diffraction from large width (poorly radius-ed) baffles and particularly large horns, but at the likely compromise of localizing the speakers (to some extent) which is often a bit ameliorated with further listening distance (which in itself ALSO increases Image width by increasing the room's side-wall reflections relative to direct sound as already noted).
As for increasing the listening AREA for width (multi-listener or lateral moving listener): that's usually just a matter of horizontal dispersion. A wide (like 50 degrees +/-) uniform horizontal dispersion from 1 kHz up to about 7 kHz does this pretty well. Lower diffraction effects a bit lower than this range tend to make the result more clear.
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Yeah, perhaps outlining what's the difference between being in sweet spot and out of sweet spot is? The listening area.
At sweetspot there is:
1) the good frequency response
2) the stereo image, described by what you like, people like different things
3) something else?
1) To have nice frequency response through out the room speaker directivity needs to be either flat or at least smooth. Trick is to have the frequency response nice to wide enough listening window, through out the room if that is what is sought after, what ever that is. Required coverage angle can be quite easily calculated and taken as target. Nice power response as well, but usually power response and listening window response go hand in hand, more or less, both require careful acoustic design which the filters are part of but its mainly about the physical construct.
Besides speaker directivity room modes break the frequency response at low frequencies, so deal with that somehow, either by acoustic treatment and / or perhaps multiple sources, perhaps with directivity.
2) stereoimage, width, height, depth, and localization of "instruments", "soundstage", stuff like this is described often for stereo image qualities. Because the image is based on phantom image, illusion born in brain based on various cues from two sound sources and reflections happening in the room, the illusion breaks easily. Toe in and directivity helps here, look for time / intensity trading to "stabilize" center image. It is possible to maintain phantom center somewhat center of speakers with this. Typical hifi setup images found on internet show exactly opposite, no toe-in with wide coverage systems, which collapses the phantom center to the speaker which is closest to you because its louder and closer. This could be option as well its just that its not possible to have pinpoint imaging through out the room, holograph that would stay in place even when the listener moves. It depends which one you are looking for, accurate or big. Its also easy to lose "spaciousness" or envelopment which are also important (in addition to image "sharpness"). Can reduce to zero if too much acoustic treatment, which might be required to have nice early reflections to more than one listening spot. Distance, go too far (relative to room) and balance between direct / reflected sound changes and the accuracy of stereo image changes between accurate and diffuse. Multitude of things would affect on many aspects, and it depends what one is looking for.
Its the stereo qualities that are hard to maintain, but just use dedicated center speaker and the illusion should be much better. This can be done quite nicely with single speaker stereo as well, but the imaging accuracy is again compromised some, but sound is pretty much the same through out the room. Key is to get rid of the phantom image, replace that with real source. But, one can get quite far with smooth directivity speakers and careful positioning.
At sweetspot there is:
1) the good frequency response
2) the stereo image, described by what you like, people like different things
3) something else?
1) To have nice frequency response through out the room speaker directivity needs to be either flat or at least smooth. Trick is to have the frequency response nice to wide enough listening window, through out the room if that is what is sought after, what ever that is. Required coverage angle can be quite easily calculated and taken as target. Nice power response as well, but usually power response and listening window response go hand in hand, more or less, both require careful acoustic design which the filters are part of but its mainly about the physical construct.
Besides speaker directivity room modes break the frequency response at low frequencies, so deal with that somehow, either by acoustic treatment and / or perhaps multiple sources, perhaps with directivity.
2) stereoimage, width, height, depth, and localization of "instruments", "soundstage", stuff like this is described often for stereo image qualities. Because the image is based on phantom image, illusion born in brain based on various cues from two sound sources and reflections happening in the room, the illusion breaks easily. Toe in and directivity helps here, look for time / intensity trading to "stabilize" center image. It is possible to maintain phantom center somewhat center of speakers with this. Typical hifi setup images found on internet show exactly opposite, no toe-in with wide coverage systems, which collapses the phantom center to the speaker which is closest to you because its louder and closer. This could be option as well its just that its not possible to have pinpoint imaging through out the room, holograph that would stay in place even when the listener moves. It depends which one you are looking for, accurate or big. Its also easy to lose "spaciousness" or envelopment which are also important (in addition to image "sharpness"). Can reduce to zero if too much acoustic treatment, which might be required to have nice early reflections to more than one listening spot. Distance, go too far (relative to room) and balance between direct / reflected sound changes and the accuracy of stereo image changes between accurate and diffuse. Multitude of things would affect on many aspects, and it depends what one is looking for.
Its the stereo qualities that are hard to maintain, but just use dedicated center speaker and the illusion should be much better. This can be done quite nicely with single speaker stereo as well, but the imaging accuracy is again compromised some, but sound is pretty much the same through out the room. Key is to get rid of the phantom image, replace that with real source. But, one can get quite far with smooth directivity speakers and careful positioning.
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Edit time over 🙂 Two speakers can get one quite far, but if you liked to have the "holographic" sound, sound of stereo signal staying place even if you move in the room, then you might need to resort to multichannel setup. Narrow coverage speakers on front, center speaker to keep the image stable, and if the envelopment was lost just add some back channels to restore and so on. Multiple subs perhaps, or some other solution for bass. Probably room acoustic treatment required. Even then stuff breaks down when you get out of the perimeter so, you might need to put speakers against walls / in-wall. How far you wanna go?🙂 Head tracking.
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