wesayso said:
@wesayso
A common mistake IMO:
Supposing someone disagreeing - with certain techniques in certain cases of application - would not understand what he is disagreeing with ...
The "corrrection" technique proposed here tries avoiding errors of different approaches (surely), but does not circumvent the underlying major problem:
On axis response - responsible for direct sound from a speaker in a room reaching the listener - being "flat and smooth" is a major factor in listener's preference.
Thus if you compromise on axis response in mid to high range - no matter whatsoever noble reasons you take as a justification for doing so - you are simply "off the road" in terms of what educated and experienced people name "good sound" or "good sound reproduction".
That's all i have to say here and i feel we should leave it this way, at least we might agree that i will leave the discussion here ...
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Let's have a closer look (again) at just the first captions following the "Introduction" in Dr. Floyd Toole's Paper linked in the starting post:
"The Measurement and Calibration of Sound
Reproducing Systems"
https://secure.aes.org/forum/pubs/journal/?ID=524
This paper is (or seems as being ...) the "anchor" of this whole thread, which is (would have been ...) a real good starting point IMO.
The Captions read as follows :
1 INTRODUCTION
2 SOUND FIELDS IN ROOMS
2.1 Sound Source Directivity as a Function of
Frequency
2.2 Room Reflections as a Function of
Frequency
For those of you able to read even captions of a paper, you also find a line of thought here, which may serve discussing the topic in an adequate manner.
I am fine if you try to avoid this consequently, but then i have to state frankly, this being "just another authority vs. gear manufacturer thread" when coming from the starting post ...
Being beyond the 50 now i say to myself: No lifetime to waste, sorry.
"The Measurement and Calibration of Sound
Reproducing Systems"
https://secure.aes.org/forum/pubs/journal/?ID=524
This paper is (or seems as being ...) the "anchor" of this whole thread, which is (would have been ...) a real good starting point IMO.
The Captions read as follows :
1 INTRODUCTION
2 SOUND FIELDS IN ROOMS
2.1 Sound Source Directivity as a Function of
Frequency
2.2 Room Reflections as a Function of
Frequency
For those of you able to read even captions of a paper, you also find a line of thought here, which may serve discussing the topic in an adequate manner.
I am fine if you try to avoid this consequently, but then i have to state frankly, this being "just another authority vs. gear manufacturer thread" when coming from the starting post ...
Being beyond the 50 now i say to myself: No lifetime to waste, sorry.
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Now why would quoting Toole help us. Yes, I've studied his work. And studied other views as well. That doesn't mean I have to agree on all of it.
Have you read where Toole and Raimonds disagree? And as a matter of fact you probably know where Geddes and Toole disagree, I assume as you've often talked with Geddes here.
There are many more views from others and I tried to study, that also made sense to me. Dunlavy comes to mind, as well as Tom Danley. But I didn't and won't hang my views and believes on one person only, well except for what I get out of it personally. I'm perfectly able to make up my own mind in the end. Bring up good points and you may sway me. Quoting Toole like you do here is not going to help. I have read it and for the most part agree with it. And by that I mean the story behind the captions. But I also now why I deviate from some of his believes. Without breaking the laws of physics. Still taking into account what it is he showed us. You've got to work on speakers and room as a whole.
I don't have the luxury of an anechoic chamber to do my testing. But that doesn't mean I cannot question what he got out of it.
One big part that I don't see Toole mention is the importance of phase for our perception and enjoyment of music. For me it's a vital part of what I was trying to achieve. There are certainly more deviations from my side but I won't go into that. Perception is a strange thing. Make use of that and you can have a blast!
Have you read where Toole and Raimonds disagree? And as a matter of fact you probably know where Geddes and Toole disagree, I assume as you've often talked with Geddes here.
There are many more views from others and I tried to study, that also made sense to me. Dunlavy comes to mind, as well as Tom Danley. But I didn't and won't hang my views and believes on one person only, well except for what I get out of it personally. I'm perfectly able to make up my own mind in the end. Bring up good points and you may sway me. Quoting Toole like you do here is not going to help. I have read it and for the most part agree with it. And by that I mean the story behind the captions. But I also now why I deviate from some of his believes. Without breaking the laws of physics. Still taking into account what it is he showed us. You've got to work on speakers and room as a whole.
I don't have the luxury of an anechoic chamber to do my testing. But that doesn't mean I cannot question what he got out of it.
One big part that I don't see Toole mention is the importance of phase for our perception and enjoyment of music. For me it's a vital part of what I was trying to achieve. There are certainly more deviations from my side but I won't go into that. Perception is a strange thing. Make use of that and you can have a blast!
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Here goes another "I've done this way all my life and I feel it's the only way."
Some people are just afraid of change and new ways of doing things.
That's ok.
There will always be vocal ones saying "this is the only way I know."
There's no more curiosity, no more excitement of threading new grounds. Only dogma is left.
I do not have the excessive baggage of "audio knowledge" from the last 50 years, so maybe I am blessed with keeping an open mind. Still, I'm no spring chicken!
I, for one, believe in the power of DRC. I've heard it in my context, my small corner of the world, and it makes a difference.
It's enough for me.
Some people are just afraid of change and new ways of doing things.
That's ok.
There will always be vocal ones saying "this is the only way I know."
There's no more curiosity, no more excitement of threading new grounds. Only dogma is left.
I do not have the excessive baggage of "audio knowledge" from the last 50 years, so maybe I am blessed with keeping an open mind. Still, I'm no spring chicken!
I, for one, believe in the power of DRC. I've heard it in my context, my small corner of the world, and it makes a difference.
It's enough for me.
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Yes Perceval I have to agree, it's working im my small corner of the world too, in my room to be more exact. I'll stop arguing as it makes no sense to do so. I'm not even defending Raimonds here as I'm pretty sure he's capable enough to do that himself.
I was defending what exactly... I guess I'm defending the freedom to think for myself. To gain something useful from that. So far it's working for me.
Edit: So far the early reviews of the new B&O monster, the Beolab 90 seems to prove there's more than one way too.
I was defending what exactly... I guess I'm defending the freedom to think for myself. To gain something useful from that. So far it's working for me.
Edit: So far the early reviews of the new B&O monster, the Beolab 90 seems to prove there's more than one way too.
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Its all just a matter of time....
I agree totally with this.
Phase / time domain accuracy in all digital manipulation (Eq, crossover, delay etc) is vital.
Imagine playing a violin recording on a single studio monitor, now simply replace the studio monitor and replay system with the actual violin....
Does the violin now sound wrong because it is radiating in 360 degrees and introduces a myriad of room reflections? Does it sound wrong because it does not benefit from a wave guide / horn for "perfect" constant directivity
It sounds "right" because our hearing has evolved to decode time domain information ie the compression and rarefactions in air pressure and decode the naturally occurring myriad of room reflections.
This holds true in recording studios' domestic rooms, concert halls or in an open field....See attached for more on the Human Auditory System (HAS) and how sound is all about time and not frequency response.
Currently there is a phase / time domain penalty (as well as a computing power price) whenever one manipulates the sound....Even Fab Filter Pro which is the defacto studio grade Eq plug in cannot implement arbitary FIR filters with zero time domain and rounding errors.
The audio world needs a time domain perfect, low computing power demand zero delay Eq / filter / crossover. Does the OP software offer this?
Also taking a step back, I believe there is much work to done on the source ie the driver itself.
The driver must mimic the original sound as closely as possible, phase is a critical part of this and correct time domain / impulse response across the broadest possible vertical and horizontal axis.
Hope this helps and all the best
Derek.
I agree totally with this.
Phase / time domain accuracy in all digital manipulation (Eq, crossover, delay etc) is vital.
Imagine playing a violin recording on a single studio monitor, now simply replace the studio monitor and replay system with the actual violin....
Does the violin now sound wrong because it is radiating in 360 degrees and introduces a myriad of room reflections? Does it sound wrong because it does not benefit from a wave guide / horn for "perfect" constant directivity
It sounds "right" because our hearing has evolved to decode time domain information ie the compression and rarefactions in air pressure and decode the naturally occurring myriad of room reflections.
This holds true in recording studios' domestic rooms, concert halls or in an open field....See attached for more on the Human Auditory System (HAS) and how sound is all about time and not frequency response.
Currently there is a phase / time domain penalty (as well as a computing power price) whenever one manipulates the sound....Even Fab Filter Pro which is the defacto studio grade Eq plug in cannot implement arbitary FIR filters with zero time domain and rounding errors.
The audio world needs a time domain perfect, low computing power demand zero delay Eq / filter / crossover. Does the OP software offer this?
Also taking a step back, I believe there is much work to done on the source ie the driver itself.
The driver must mimic the original sound as closely as possible, phase is a critical part of this and correct time domain / impulse response across the broadest possible vertical and horizontal axis.
Hope this helps and all the best
Derek.
Once again guys:
If you cannot adjust the dispersion pattern of your speakers according to your setting in the actual listening room, you are "just spectators of the scene".
You turn the only knobs you may have left or that someone else is providing to you, kindly writing "room correction" on those knobs of the package.
But unfortunately those knobs are not the relevant ones especially from midrange to highs. It is as simple ...
That overflowing discussions always running in the very same circles are also indicators in itself for those, who are able to take a meta level point of view.
It may truly be hard to feel helpless with regard to the real underlying problem: I understand that very well and surely better than most of you discussing here using just "personal and subjetive anectodic evidence", which is worth plain nothing to anyone anywhere.
But just sympathy with others does not solve a problem in itself, had never done in the past and will never do in future.
So YOU would have to convince ME to leave the "relevant knobs" out(!) just to pull the less relevant or even irrelevant ones .
You will have a very hard time in trying that, i can assure you: And you will have to do that even without me being present in this "thread of the helpless knob turners gathering anectodical evidence due to 'room correction' ".
(As you might have noticed, i did not talk about "loudspeaker correction" at all ...)
If you cannot adjust the dispersion pattern of your speakers according to your setting in the actual listening room, you are "just spectators of the scene".
You turn the only knobs you may have left or that someone else is providing to you, kindly writing "room correction" on those knobs of the package.
But unfortunately those knobs are not the relevant ones especially from midrange to highs. It is as simple ...
That overflowing discussions always running in the very same circles are also indicators in itself for those, who are able to take a meta level point of view.
It may truly be hard to feel helpless with regard to the real underlying problem: I understand that very well and surely better than most of you discussing here using just "personal and subjetive anectodic evidence", which is worth plain nothing to anyone anywhere.
But just sympathy with others does not solve a problem in itself, had never done in the past and will never do in future.
So YOU would have to convince ME to leave the "relevant knobs" out(!) just to pull the less relevant or even irrelevant ones .
You will have a very hard time in trying that, i can assure you: And you will have to do that even without me being present in this "thread of the helpless knob turners gathering anectodical evidence due to 'room correction' ".
(As you might have noticed, i did not talk about "loudspeaker correction" at all ...)
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Nobody said that any form of digital room correction could "adjust the dispersion pattern of your speaker". I think everybody here understands that it is physically impossible.
I don't feel "helpless". I simply acknowledge the limitations in our understanding of how the human hearing system works. I also don't brush off the reports of others as worthless. That would be rude and ultimately undermines what science is all about. Ignoring evidence doesn't make you understand things better it just makes you a dogmatist.
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That could be a start:
But i did not even say that anyone else said
"that any form of room correction could adjust the dispersion pattern of your speaker".
I know that you all (should at least) also know, that this is impossible using "usual" DRC products (including the one discussed here ...), leaving the architecture of the given loudspeakers involved unchanged:
This is why i know that you could know, you are not able to turn the relevant knobs.
In fact an adjustable dispersion pattern is a relevant way to (efficient and causal) "room compensation" (a better term maybe as 'room correction', which has a 'marketing flavour' associated with it IMO) as i see it.
But i feel this topic would be wrong to be discussed here in this thread:
Because this thread is not about the relevant things needed for effective and causal "room compensation" ... (*)
Maybe at least some of you - or even some of the 'silent readers' - now got the hang of it.
__________________
(*) Especially when discussing mid to high frequencies also.
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I've been monitoring and reading what is being said and it is very circuitous and highly unlikely there will be a consensus. While I agree with Derek and Wesayso that phase is important in the actual loudspeaker and we should do better at this than is commonly done once you introduce the room to the equation all bets are off.
What I think we have to understand is that most people, not the group here but the common person will not treat their rooms, nor correctly place a loudspeaker in a room, that is not going to be a part of the equation in 99% or greater what is going to happen with a consumer, unlike here with diy audio types. So what can be done commercially is very different than what can be done by those in this forum.
That being the case we have to choose our own poison, what we personally prefer, and all of this becomes preferences. Some may choose to use CD horns with very controlled directivity and massive room treatments, not ever wife approved, or some go in the other direction and want an MBL type of solution with omnidirectional dispersion and attempt to as Derek brought up attempt to recreate the actual function of a real instruments dispersion. Problem with that is the recording technique does not support that notion.
So as someone who has to produce a product for the average Joe, the person on the street who knows nothing of room correction, acoustics or speaker design where do you have to fall? I agree that there needs to be a few knobs, something that allows a normal listener, not us, to make some adjustments to the sound so that they like what they hear, whether this is correct technically or not. If there is a way, and of course there is, but at what cost, we could include auto room correction, but this would require the placement of at least one microphone in the listening position.
So the question is where do you draw the line of what is practical and what is possible. I don't care about what is done in an anechoic chamber, it is truly irrelevant to a listening room. That is only useful for testing and nothing to do with actual reproduction of sound. Thiel, Linkewitz, Toole, Geddes, they all have their own opinions, nobodies is superior to another, they are all useful as information goes, but you really have to come to your own conclusions as to what is acceptable to your personal taste. There is no one size fits all solutions.
If we are the room designers and can select the speakers and assemble the system then we are way ahead of 99.9% of the what people have to listen to. But that is why you are here, you have that ability to select and design to the level that you can. beyond that if we bring this conversation into the consumer realm all this is moot, there are no better solutions today than there were 20 or more years ago. Go in over to the Beyond the Ariel thread and they are arguing SS vs tubes and high efficiency large horns and drivers.
Automated DRC with exceptional speakers are a great thing for those who understand there will always be compromises in every system. To argue that you have the solution to every speaker and room interaction is just useless. We all have to find our own way and make ourselves happy, what else is truly possible.
What I think we have to understand is that most people, not the group here but the common person will not treat their rooms, nor correctly place a loudspeaker in a room, that is not going to be a part of the equation in 99% or greater what is going to happen with a consumer, unlike here with diy audio types. So what can be done commercially is very different than what can be done by those in this forum.
That being the case we have to choose our own poison, what we personally prefer, and all of this becomes preferences. Some may choose to use CD horns with very controlled directivity and massive room treatments, not ever wife approved, or some go in the other direction and want an MBL type of solution with omnidirectional dispersion and attempt to as Derek brought up attempt to recreate the actual function of a real instruments dispersion. Problem with that is the recording technique does not support that notion.
So as someone who has to produce a product for the average Joe, the person on the street who knows nothing of room correction, acoustics or speaker design where do you have to fall? I agree that there needs to be a few knobs, something that allows a normal listener, not us, to make some adjustments to the sound so that they like what they hear, whether this is correct technically or not. If there is a way, and of course there is, but at what cost, we could include auto room correction, but this would require the placement of at least one microphone in the listening position.
So the question is where do you draw the line of what is practical and what is possible. I don't care about what is done in an anechoic chamber, it is truly irrelevant to a listening room. That is only useful for testing and nothing to do with actual reproduction of sound. Thiel, Linkewitz, Toole, Geddes, they all have their own opinions, nobodies is superior to another, they are all useful as information goes, but you really have to come to your own conclusions as to what is acceptable to your personal taste. There is no one size fits all solutions.
If we are the room designers and can select the speakers and assemble the system then we are way ahead of 99.9% of the what people have to listen to. But that is why you are here, you have that ability to select and design to the level that you can. beyond that if we bring this conversation into the consumer realm all this is moot, there are no better solutions today than there were 20 or more years ago. Go in over to the Beyond the Ariel thread and they are arguing SS vs tubes and high efficiency large horns and drivers.
Automated DRC with exceptional speakers are a great thing for those who understand there will always be compromises in every system. To argue that you have the solution to every speaker and room interaction is just useless. We all have to find our own way and make ourselves happy, what else is truly possible.
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Kindhornman" said:
A loudspeaker having "widely and usefully" adjustable dispersion (to be shown in DI curves and especially "early reflections DI" curves) e.g. in mid-to-highs is from today's common view like choosing among different speakers for a particular listening room and placement by simply "adjusting the speaker you have" ...
I developed such 400Hz ... 20Khz "chamaeleon-like" devices and use them in my own speaker designs especially in ambitious customer's projects.
Fine tuning the room curves on site while maintaining neutral (anechoic) on axis response is possible for me to achieve this way.
That is imposssible to any conventional "DRC" approach. Nevertheless what i do in these mid-to-high range devices is rather simple from the underlying core principle. Technical detail is not that simple of course ...
Even microphones having adjustable polar patterns are well known in studios and may serve as examples for "general feasibility" of such an approach without going into detail here.
There are considerations, whether to make that mid-to-high transducer available even to DIYers in some time in the future: There has been some interest signaled e.g. from german DIY-media. But i am not sure concerning that. So right now the use is restricted to my own custom built designs.
Kind Regards
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LineArray,
No arguments from me on anything but the microphone comment. It doesn't matter what mic or pattern you use, you are not going to reproduce the sound field that is coming directly off a real instrument, that is where the illusion falls apart. You may get a very nice sound and reproduction of the harmonics of the instrument, but you are not going to reproduce the radiation pattern of that instrument, that was my real point. The other reality of those comments about a 360 degree radiation pattern is even then that isn't truly an omnidirectional pattern. the person playing that instrument changes the radiation pattern with their body and the position of any F-holes or radiation surfaces are not monotonic, they are different in every direction, you just could never and I mean never actually reproduce that radiation pattern exactly like it is produce from whatever instrument we are talking about, just not going to happen.
If you have your own solution that you use for mids and highs that works in the rooms that you install into that is great. But that is not a commercially available product as you say and so to compare every other system to what you are personally doing is just irrelevant to these conversations.
No arguments from me on anything but the microphone comment. It doesn't matter what mic or pattern you use, you are not going to reproduce the sound field that is coming directly off a real instrument, that is where the illusion falls apart. You may get a very nice sound and reproduction of the harmonics of the instrument, but you are not going to reproduce the radiation pattern of that instrument, that was my real point. The other reality of those comments about a 360 degree radiation pattern is even then that isn't truly an omnidirectional pattern. the person playing that instrument changes the radiation pattern with their body and the position of any F-holes or radiation surfaces are not monotonic, they are different in every direction, you just could never and I mean never actually reproduce that radiation pattern exactly like it is produce from whatever instrument we are talking about, just not going to happen.
If you have your own solution that you use for mids and highs that works in the rooms that you install into that is great. But that is not a commercially available product as you say and so to compare every other system to what you are personally doing is just irrelevant to these conversations.
Kindhornman said:
I did not state such a thing ... because it was not my topic.
My intention was solely to give a vivid technical example for acoustic transducers having adjustable polar patterns. As you know, there are some interrelations in design between microphones and loudspeakers.
Which may serve as a clue, i am not talking about any kind of witchcraft here (not at all ...).
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Who am i to criticize your view on the relevance of "what i am doing" ?
But the principle itself - adjustable polar pattern - is fairly independent in relevance (to the thread's topic) from anyone making a product of it or where to offer that product.
That is my view on matters discussed here.
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LineArray,
Now I am following your comment, I do understand your analogy. The question to me then becomes what type of diaphragm surface on your drivers you are using to be able to modify the radiation pattern at will? Unless of course you are creating a phase array using multiple drivers to control the pattern.
Now I am following your comment, I do understand your analogy. The question to me then becomes what type of diaphragm surface on your drivers you are using to be able to modify the radiation pattern at will? Unless of course you are creating a phase array using multiple drivers to control the pattern.
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@Kindhornman,
intentionally i will not comment on technical composition or detail, sorry.
It does not matter to this discussion anyhow, but the principle itself is worth thinking about IMHO, as it helps solving a problem at (or near ...) "it's roots".
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LineArray,
The way I see it, what you hear is a combination of speaker directivity and room absorption. Generally, we cannot change speaker directivity. Maybe your speaker can, and we know the Beolab 90 can, but in my opinion, being able to change the directivity in the horizontal dimension is pretty much useless for home sound reproduction. As Toole and others have noted, our two ears are well placed to separate out sound that is reflected from the sides.
In terms of vertical directivity, you definitely want to be able to eliminate floor and ceiling reflections. Maybe your speakers do this. But there is no debate here, you definitely want to avoid these vertically-oriented reflections. Our hearing mechanisms cannot distinguish these reflections from the direct sound and it ends up coloring the original sound.
So far, nothing on room correction. All these are speaker issues. Moving on to what you hear at the listening position. At high frequencies the time window for what we hear is short, and low frequencies it gets longer. So, it would be ideal if we can gate our measured response using a continuously sliding time window. And DRC does exactly that. There are similar features for viewing the response in REW also. This is, in my opinion, a quantum leap in the ability to correct sound. I have been using DRC ever since Wesayso introduced it to me. At high frequencies, it is correcting the direct sound. At low frequencies, it is correcting the total sound, i.e., direct plus reflected. And this is actually what you are hearing. At 100 Hz, the perceived loudness is a sum of the direct and reflected sound (out to some finite time window). So, the correction should take into account reflected sound while doing the correction. At very low frequencies, the correction may be valid for only one listening position, because the wavelengths are very long. Now, you need multiple subs and so on to get an even response across the couch.
Not sure why there is so much debate about this. I thought this is pretty well understood by everyone.
The way I see it, what you hear is a combination of speaker directivity and room absorption. Generally, we cannot change speaker directivity. Maybe your speaker can, and we know the Beolab 90 can, but in my opinion, being able to change the directivity in the horizontal dimension is pretty much useless for home sound reproduction. As Toole and others have noted, our two ears are well placed to separate out sound that is reflected from the sides.
In terms of vertical directivity, you definitely want to be able to eliminate floor and ceiling reflections. Maybe your speakers do this. But there is no debate here, you definitely want to avoid these vertically-oriented reflections. Our hearing mechanisms cannot distinguish these reflections from the direct sound and it ends up coloring the original sound.
So far, nothing on room correction. All these are speaker issues. Moving on to what you hear at the listening position. At high frequencies the time window for what we hear is short, and low frequencies it gets longer. So, it would be ideal if we can gate our measured response using a continuously sliding time window. And DRC does exactly that. There are similar features for viewing the response in REW also. This is, in my opinion, a quantum leap in the ability to correct sound. I have been using DRC ever since Wesayso introduced it to me. At high frequencies, it is correcting the direct sound. At low frequencies, it is correcting the total sound, i.e., direct plus reflected. And this is actually what you are hearing. At 100 Hz, the perceived loudness is a sum of the direct and reflected sound (out to some finite time window). So, the correction should take into account reflected sound while doing the correction. At very low frequencies, the correction may be valid for only one listening position, because the wavelengths are very long. Now, you need multiple subs and so on to get an even response across the couch.
Not sure why there is so much debate about this. I thought this is pretty well understood by everyone.