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Joined 2003
Go to the link, download BDS, and you can simulate the effect of various roundovers quite easily. I've used up to an 8" radius with excellent results, but only 4" can provide very good results.
FRD Consortium
augerpro said:
I cannot prove this with anything, but my guess would be the same. On recordings with almost echo-like reflections (which are substantially delayed), I can easily locate the source: the speaker, and not a room.
Also, I find the spatial information in many recordings to be disappointing, although I have a few recordings which are outstanding in terms of spaciousness. I believe this may vary a great deal depending on your taste in music, so others may disagree on this.
Last but not least, my speakers may be of importance, since they're not really state of the art, although at least the frequency response is good. I'm working on a set of prototype dipoles with the Visaton GF 200 and BG Neo3 PDR, just to try out the dipole approach. I'm curious to see what those will do with respect to imaging.
@ Daygloworange: Your comments have made me think about the subject. However, IMHO the amount of spatial information is not satisfactory in a great deal of (studio) music, and I'm not sure if recorded reflections alone, coming from two speakers, can fool you into believing you're in a concert hall.
Mantraxl, my understanding (based on a conversation with Earl Geddes) is that a roundover is effective at and above the frequency where the radius is equal to a quarter of a wavelength; at lower frequencies it is not effective. So a 1" radius roundover should be good down to about 3.4 kHz; 2" good down to 1.7 kHz, and so on.
Duke
Duke
Hey guys, I'm not simply offering an opinion here for the sake of being oppositional, so I hope no one takes my comments on a personal level.
I have over 20 years of recording experience, and have been playing around with stereo miking since day one, and have even made my own Q4 type quadraphonic recordings.
I am an imaging "junkie" .
Not with a good recording, and a good source (speakers, room and front end audio components).
The problem is (as noted) that a lot of recordings are far from being technically well done to illustrate my point. But properly done phase correct stereo recordings (such as binaural or well done X/Y mic recordings) can sound frighteningly real coming from a pair of speakers. With a really, really good playback chain, in a really well treated room, you cannot localize the speakers.
It sounds as if the whole front wall is a large transducer. Of course the only thing that 2 channels won't do is localization of height, but in most musical acoustic events, we are not sitting at a proximity close enough, or listening to a source that has a lot of height differential to make this a serious enough issue for discussion here.
In a (near perfect) example of a properly done binaural, or X/Y recording, the mic diaphrams are positioned aiming towards a source, in order to simulate arrivals to ears on a human's head. The polar patterns (the mic's pickup pattern) are angled in such a way as to be the inverse of a (theoretically generic) typical equilateral speaker/listener placement.
The problem is, a lot of tricks that are done for (someone's own)subjective reasons, blur what many a recording "could have been". So given the vast majority of recordings, it makes us search for other areas, and all too often, the speakers or the whole act of audio reproduction is blamed.
If the "real" reflections present during a recording session are captured properly, then the ear can be quite convinced it's listening to a real event.
Although digital reverbs have come a long, long way in terms of sounding quite realistic, there is no mistaking a stereo ambient (mic'ed) recording.
No, actually, that's close to an ideal scenario (discounting the fact that speakers are designed to couple with the floor, and that room gain is factored into it's bass response.
What would contribute to unnatural is simply that no one listens to audio in a completely reflection free environment. The act of breathing in an anechoic environment is freaky for some. Some people develop anxiety and clausterphobia in such a freakishly quite, reflection free space in a short period of time.
As a counter illustration, imagine any source, (real acoustic event, or audio sytem reproduction) in a really big school gymnasium (without diffusive elements like bleachers etc..). It would just be a large conglomeration of(high ratio of relected vs direct) sounds. Intelligibilty would be almost zero.
Depending on the hall, and where you are sitting. Some halls have very hard surfaces, in which case, you would get quite some information reflected to you from the sides and ceiling, and echoed to you from the back wall. In this scenario, only a Quadraphonic recording would sufficiently approximate that, but a number of more modern (or updated) halls have the surfaces treated with absorption and diffusion to minimize the reflections, echoes and associated comb filtering effects.
Of course there are few perfect real life models of what I describe, but the blame must be put in the proper place.
Poor (unnatural and non transparent) recordings are the constraint, not the playback system.
Cheers
I have over 20 years of recording experience, and have been playing around with stereo miking since day one, and have even made my own Q4 type quadraphonic recordings.
I am an imaging "junkie" .
Not with a good recording, and a good source (speakers, room and front end audio components).
The problem is (as noted) that a lot of recordings are far from being technically well done to illustrate my point. But properly done phase correct stereo recordings (such as binaural or well done X/Y mic recordings) can sound frighteningly real coming from a pair of speakers. With a really, really good playback chain, in a really well treated room, you cannot localize the speakers.
It sounds as if the whole front wall is a large transducer. Of course the only thing that 2 channels won't do is localization of height, but in most musical acoustic events, we are not sitting at a proximity close enough, or listening to a source that has a lot of height differential to make this a serious enough issue for discussion here.
In a (near perfect) example of a properly done binaural, or X/Y recording, the mic diaphrams are positioned aiming towards a source, in order to simulate arrivals to ears on a human's head. The polar patterns (the mic's pickup pattern) are angled in such a way as to be the inverse of a (theoretically generic) typical equilateral speaker/listener placement.
The problem is, a lot of tricks that are done for (someone's own)subjective reasons, blur what many a recording "could have been". So given the vast majority of recordings, it makes us search for other areas, and all too often, the speakers or the whole act of audio reproduction is blamed.
If the "real" reflections present during a recording session are captured properly, then the ear can be quite convinced it's listening to a real event.
Although digital reverbs have come a long, long way in terms of sounding quite realistic, there is no mistaking a stereo ambient (mic'ed) recording.
No, actually, that's close to an ideal scenario (discounting the fact that speakers are designed to couple with the floor, and that room gain is factored into it's bass response.
What would contribute to unnatural is simply that no one listens to audio in a completely reflection free environment. The act of breathing in an anechoic environment is freaky for some. Some people develop anxiety and clausterphobia in such a freakishly quite, reflection free space in a short period of time.
As a counter illustration, imagine any source, (real acoustic event, or audio sytem reproduction) in a really big school gymnasium (without diffusive elements like bleachers etc..). It would just be a large conglomeration of(high ratio of relected vs direct) sounds. Intelligibilty would be almost zero.
Depending on the hall, and where you are sitting. Some halls have very hard surfaces, in which case, you would get quite some information reflected to you from the sides and ceiling, and echoed to you from the back wall. In this scenario, only a Quadraphonic recording would sufficiently approximate that, but a number of more modern (or updated) halls have the surfaces treated with absorption and diffusion to minimize the reflections, echoes and associated comb filtering effects.
Of course there are few perfect real life models of what I describe, but the blame must be put in the proper place.
Poor (unnatural and non transparent) recordings are the constraint, not the playback system.
Cheers
After a bit of experiments treating my room, I am becoming to believe that a well damped room, especailly with all first / short reflection points treated, helps improve imaging dramatically. This really get you listen to the original acoustic space of the performance, i.e. "You are there", watching and hearing a live performance.
The problem may be that a lot of recordings are lack of ambient information. I listen to live, unamplified (classical) performances from time to time, and found there is a significant amount of ambient sound. In real life performances, we rarely get very close to the performers, and possibly hear more of the ambient sound than the direct sound. In other words, we may listen in a far-field (where SPL of reflected signals are larger than direct signals) more often than near-field (where direct signals are stronger than reflected signals), and that forms our idea of what a live performance is about. In many recordings with direct sound much more than the ambient sound, when played back in a damped room without the artificial room ambience, the music may become dry.
Many people like dipole speakers. I guess it is possibly because of more balanced (in terms of frequency spectrum) reflections from the front wall, creating an ambient effect that is lacking in many recordings. In a reverbrant room, the experience of listening to music is like "They (the musicians) are here" instead of "you are there".
I am still experimenting. I think when sitting in front of the (high fidelity in terms of low distortion) system, I prefer the room to be damped so that I can listen to the original performance. But when I sit in my lounge room eating dinner playing music in the next, dedicated music room, I prefer the music room to be more reverberant, so that I get an illusion that the musicians are playing in the next room. My music room is become more and more damped, and I am loosing that sort of illusion.
Thawach,
Perhaps when I go to Thailand (I love your country) next time I will come and see what especial image you want to listen to. I was in Thailand for possibly a dozen times and may go again next year or so.
Regards,
Bill
The problem may be that a lot of recordings are lack of ambient information. I listen to live, unamplified (classical) performances from time to time, and found there is a significant amount of ambient sound. In real life performances, we rarely get very close to the performers, and possibly hear more of the ambient sound than the direct sound. In other words, we may listen in a far-field (where SPL of reflected signals are larger than direct signals) more often than near-field (where direct signals are stronger than reflected signals), and that forms our idea of what a live performance is about. In many recordings with direct sound much more than the ambient sound, when played back in a damped room without the artificial room ambience, the music may become dry.
Many people like dipole speakers. I guess it is possibly because of more balanced (in terms of frequency spectrum) reflections from the front wall, creating an ambient effect that is lacking in many recordings. In a reverbrant room, the experience of listening to music is like "They (the musicians) are here" instead of "you are there".
I am still experimenting. I think when sitting in front of the (high fidelity in terms of low distortion) system, I prefer the room to be damped so that I can listen to the original performance. But when I sit in my lounge room eating dinner playing music in the next, dedicated music room, I prefer the music room to be more reverberant, so that I get an illusion that the musicians are playing in the next room. My music room is become more and more damped, and I am loosing that sort of illusion.
Thawach,
Perhaps when I go to Thailand (I love your country) next time I will come and see what especial image you want to listen to. I was in Thailand for possibly a dozen times and may go again next year or so.
Regards,
Bill
After a bit of experiments treating my room, I am becoming to believe that a well damped room, especailly with all first / short reflection points treated, helps improve imaging dramatically. This really get you listen to the original acoustic space of the performance, i.e. "You are there", watching and hearing the live performance.
The problem may be that a lot of recordings are lack of ambient information. I listen to live, unamplified (classical) performance from time to time, and found there is very significant ambient sound. In real life performance, we rarely get very close to the performers, and we possibly hear more of the ambient sound than the direct sound. In other words, we may listen in a far-field (where SPL of reflected signals are larger than direct signals) more often than near-field (where direct signals are stronger than reflected signals), and that forms our idea of what a live performance is about. In many recordings with direct sound much more than the ambient sound, when played back in a damped room without the artificial room ambience, the music may become a bit dry.
Many people like dipole speakers. I guess it is possibly because of more balanced (in terms of frequency spectrum) reflections from the front wall, creating an ambient effect that is lacking in many recordings. In a reverbrant room, the experience of listening to music is like "They (the musicians) are here" instead of "you are there".
I am still experimenting. I think when sitting in front of the (high fidelity in terms of low distortion) system, I prefer the room to be damped so that I can listen to the original performance. But when I sit in my lounge room eating dinner playing music in a dedicated music room, I prefer the music room to be more reverberant, so that I get an illusion that the musicians are playing in the next room. With a overly damped room, I may lose that sort of illusion.
Thawach,
Perhaps when I go to Thailand (I love your country) next time I will come and see what especial image you want to listen to. I was in Thailand for possibly a dozen times and may go again next year or so.
Regards,
Bill
The problem may be that a lot of recordings are lack of ambient information. I listen to live, unamplified (classical) performance from time to time, and found there is very significant ambient sound. In real life performance, we rarely get very close to the performers, and we possibly hear more of the ambient sound than the direct sound. In other words, we may listen in a far-field (where SPL of reflected signals are larger than direct signals) more often than near-field (where direct signals are stronger than reflected signals), and that forms our idea of what a live performance is about. In many recordings with direct sound much more than the ambient sound, when played back in a damped room without the artificial room ambience, the music may become a bit dry.
Many people like dipole speakers. I guess it is possibly because of more balanced (in terms of frequency spectrum) reflections from the front wall, creating an ambient effect that is lacking in many recordings. In a reverbrant room, the experience of listening to music is like "They (the musicians) are here" instead of "you are there".
I am still experimenting. I think when sitting in front of the (high fidelity in terms of low distortion) system, I prefer the room to be damped so that I can listen to the original performance. But when I sit in my lounge room eating dinner playing music in a dedicated music room, I prefer the music room to be more reverberant, so that I get an illusion that the musicians are playing in the next room. With a overly damped room, I may lose that sort of illusion.
Thawach,
Perhaps when I go to Thailand (I love your country) next time I will come and see what especial image you want to listen to. I was in Thailand for possibly a dozen times and may go again next year or so.
Regards,
Bill
Well there are clearly some disagreements on the effect of added room reflections. But let's say that's a matter of preference, perhaps influenced by the spatial information in the recording listened to.
Still, I believe there are a few speaker characteristics that are important for imaging regardless of the outcome of the previous discussion. So let's return to the speaker again (which I believe was the main subject).
@Daygloworange: Would you consider constant directivity to be an important characteristic of a speaker when designing for imaging? Or would simply high (but not constant) directivity do the trick? High directivity is difficult to achieve at lower frequencies, though it might be irrelevant there because the ear cannot separate direct sound and reflections in that region, if I'm not mistaken.
Isn't it true that the ear is good at masking reflections in the mid-high frequency band? Siegfried Linkwitz claims that the spectrum of the reflections should be more or less the same as the direct sound for the ear to "neglect" the delayed sound. Does anyone have a different source for this claim? Or is the spectrum of the reflections irrelevant?
Still, I believe there are a few speaker characteristics that are important for imaging regardless of the outcome of the previous discussion. So let's return to the speaker again (which I believe was the main subject).
@Daygloworange: Would you consider constant directivity to be an important characteristic of a speaker when designing for imaging? Or would simply high (but not constant) directivity do the trick? High directivity is difficult to achieve at lower frequencies, though it might be irrelevant there because the ear cannot separate direct sound and reflections in that region, if I'm not mistaken.
Isn't it true that the ear is good at masking reflections in the mid-high frequency band? Siegfried Linkwitz claims that the spectrum of the reflections should be more or less the same as the direct sound for the ear to "neglect" the delayed sound. Does anyone have a different source for this claim? Or is the spectrum of the reflections irrelevant?
hi notnot
now my old speaker does not have. About 15 years i modify it. i think that a foolish work. i would not like to tell you. because you will laugh. after i modify the drivers cannot use. the box sold my friend. this speaker is narrow baffle. it made in thailand.the name "RPG" 6" 2 way tw 1" xo 3.8 khz.the woofer is paper cone(cheap & noname).the Tw is plastic dome. about the image that i had ever read in magazine in thailand . they told that image sometime the expensive speakers didnot have(6000us). i listen it in your store. i listened it about 5 minutes i bought it. it had especial image. but the sound have something i don't like. total freguency is near flat. but about 12 khz is peak(3-4 db) when i listened a long time i'm tired. total sound isnot hard and not soft. but i like a little soft. cause that i modify it. the image of it can made me forget this speaker. i only listened it. when i switch off the light.i didnot knew where it is. i begin to trust mavo said about two points. but he siad it was soundstage. i sueprise when it's in bad room or good room and on the floor. it's still had the image. mini speaker i had listened too much in the store. it's only original image. it's not a chance.the company was close a long time ago. because that time thai people didnot interest about the image.
i'm glad you had ever gone to thailand. Peoples in here are easy to smile. only me is easy to angry(lol). my city have the dirt too much. dipole isn't like to use.
regards
now my old speaker does not have. About 15 years i modify it. i think that a foolish work. i would not like to tell you. because you will laugh. after i modify the drivers cannot use. the box sold my friend. this speaker is narrow baffle. it made in thailand.the name "RPG" 6" 2 way tw 1" xo 3.8 khz.the woofer is paper cone(cheap & noname).the Tw is plastic dome. about the image that i had ever read in magazine in thailand . they told that image sometime the expensive speakers didnot have(6000us). i listen it in your store. i listened it about 5 minutes i bought it. it had especial image. but the sound have something i don't like. total freguency is near flat. but about 12 khz is peak(3-4 db) when i listened a long time i'm tired. total sound isnot hard and not soft. but i like a little soft. cause that i modify it. the image of it can made me forget this speaker. i only listened it. when i switch off the light.i didnot knew where it is. i begin to trust mavo said about two points. but he siad it was soundstage. i sueprise when it's in bad room or good room and on the floor. it's still had the image. mini speaker i had listened too much in the store. it's only original image. it's not a chance.the company was close a long time ago. because that time thai people didnot interest about the image.
i'm glad you had ever gone to thailand. Peoples in here are easy to smile. only me is easy to angry(lol). my city have the dirt too much. dipole isn't like to use.
regards
a_tewinkel said:
If you've tried listening to audio in a room that's carefully treated to minimize room reflections and interactions and preferred a more reflective environment, then yes, that's your personal preference.
I don't argue personal preferences. I just explain how listening room interactions can be detrimental to proper imaging.
In a (theoretically perfect) X/Y recording, microphones would be placed in such a manner as to mimic the way a human's ears pick up a sound source coming from a forward direction.
The microphones pick up the direct sounds, and the reflected sounds coming from forward and to the sides in proper amplitude, frequency and time domain.
Depending on the room that the recording was done in, there is also a certain amount of rear reflection (depending on the polar pickup pattern of the microphones) that is picked up at the point where the microphones are located.
This information is embedded in the recording. The microphones are behaving like ears, and picking up the information as ears would.
An ideal playback (given this scenario) would be to have the information played back by speakers that are set up to reverse the capture of the event in a reflection free environment. In other words, a place where there are no other reflections. In an ideal situtation, headphones would be the best possible scenario.
I agree. But in the context of most conventional speakers, the listening room characteristics are the overruling offender. It's only once you've factored out the (damaging) effects of the listening room, can you properly begin to improve imaging at the speaker. Otherwise, you're putting the cart before the horse, and the best you can achieve are excellent results under flawed conditions.
Improve the conditions (the room), and you immediately improve the performance of the speakers.
Simple, really.
Directivity is only paramount in a listening room that is (not treated) ideal. Which most peoples' rooms are. Off axis response then becomes an issue. The flatter the off axis response, the "less" damaging the room reflections become. Take away the reflections of a listening room, then only the on axis performance of the speaker would be of concern.
The reason why dipole speakers have an inherant primary(although there are other important dipole characteristics) advantage is by design. The null 90 deg. off axis, takes away the damaging effects of the side relections of a room.
How can the ear mask reflections??? How would we get our localization cues?
Our ears are tympanic membranes. They respond to sound pressure waves. Our ears can't override the laws of physics.
Our ears are most sensitive to amplitude in 2k to 5k range.
The comments you say that Linkwitz talks about are probably about the importance of good off axis response not being overly detrimental to the imaging capabilty of a speaker due to room relections.
Our ears cannot overcome the effects of combfiltering that happens in listening rooms due to the off axis reflected sounds merging with on axis sounds coming directly from a speaker.
I do know that his Orion speaker has now become a full dipole. Previously only the mids and bass were dipole, but now he's added a rear firing tweeter to make it a (bipolar) dipole.
Cheers
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