That bears repeating. A certified software bargin. And it does way more than TLs.
dave
C'mon now, you have to get your logic straight. How can you boast about his trick program while staring at THAT data? The DATA that is on shaky ground, not me.*
Yes, Martin is both a consummate engineer (as I said plain as could be earlier) and an excellent writer.
*Personally, I think the results are great - better than I'd expect. But then I have low (read: realistic, experienced, professorial) expectations because I am a researcher. Am I surprised by the large and particularly, the irregular discrepancies between model and mic? No. That is exactly the point I've been trying to make for the last posts in this thread. Models are nice so long as you don't expect too much of them.
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Just curious, Ben; what methodology did you use putting together the system in your signature. Measured? Calculated? Trial and error?
Ben, you're missing the point. That paper is chapter one of his research and he's comparing the measured data to the old method, not his method. Any good scientist does the same thing. Those numbers are part of what inspired him to come up with his own method.
I have a bad feeling some people here think in just black-and-white, "for us or against us". One guy thought I must be a Golden Ear type. Straaaaaange.
I do like everybody. I get the electric signals where I want them and then I tweak by ear. Ever heard from any sane person who works otherwise? It should follow from what I've been saying that it is a real big mistake to design stuff without knobs, EQ, or the patience to re-do components.
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I'm neither for nor against, and am definitely not from the "black and white" camp, but, I'm still curious; when you say
, that leaves a lot of wiggle room. In the context of your system, I take it that "electric signals" also means "acoustic signals", which, in turn, would entail the use of a measurement microphone and software. Am I close? Or, by contrast, did you use store-bought active crossovers, pick your crossover points, and adjust levels by ear?
Sims vs measured
Hi to all, I' d like to add a few comments that may help bring together some of the loose strings in the "simulations are accurate vs no they are not debate".
1) The better simulators that are now in common use can be extremely accurate, within fractions of a dB in predicting response for one specific point. If the driver measurements are good, the accuracy of the simulator is such that you can almost dispense with verification measurements. (But this does not mean it will SOUND good, please read on).
2) Simulating/measuring for only the on-axis response can be fraught with peril, it rarely yields results which actually sound good to the majority of listeners.
3) Dr Toole's work showed the vast importance of having uniform Freq response on axis but ALSO off axis. He showed the AVERAGE hemispherical response needs to be very close to the on axis for it to be deemed good by a majority of listeners. (His studies were relative to direct radiator speakers, I don't believe he reported any results for open baffles or dipoles).
4) In support of Ben's experience, I have heard many, many designs (including my own ones early on) that had utterly GREAT response curves at 1m or 3m but which did NOT sound very good, but that was not because the simulations/measurements were wrong.... it was because their off axis response did not correlate well with the on axis.
It ain't the simulation, it's the overlooking of what Dr Toole pointed out, the AVERAGE response is at least as important. ESPECIALLY when you put it in a room!
In sum: the "SPATIAL coherence" of the speaker response is extremely important.
5) If the average power response is not fairly uniform and coherent with the on axis, the in room response and performance could be anywhere from lousy to fantastic, depending on how lucky we get with the combination.
Also, when attempting to eq speakers that are not "spatially coherent", it can become REALLY difficult to get any kind of in room measurement that correlates well with the listening experience. My guess would that this is what Ben has been referring to?
6) As Geddes with his controlled directivity speakers, and as Linkwitz and Krevkovsky have been showing with their OB (open baffle) designs, speakers with more uniform directionality generally sound much better in real world rooms.
Their designs DO measure well on axis, and the off axis responses also measure well, and more importantly their off axis or "spatial response" is very close to the on-axis.
Please note that these speakers generally sound very pleasing to almost all listeners, in a wide variety of rooms.
And they also tend to measure fairly well in many different positions in the room. Ask Kreskovsky if he thinks simulators are useful, and I believe he will tell you he most certainly does.
7) Ben, in relation to what you have described, I would venture the guess that when a speaker "looks great in simulations/measurements at 1 or 3 meters", but does not perform well at your listening position....well.... it is probably because too many (way too many!) designers overlook the average and off axis response and design only for on axis.
Please don't blame the simulations, they are usually quite accurate, but we need to know how to use them correctly! Methinks that what you are interpreting as an inaccuracy due to the simulations, is in fact an inaccuracy due to improper use of those sims, i.e. human error.
I've been studying these issues at depth, and believe like Linkwitz that the solution is to use open baffle or omni dispersion patterns to achieve "spatial coherence" (to coin a term) When the off axis characteristics are entirely coherent with the "on-axis" or direct response, i.e. they are "spatially coherent".
I never would have imagined this: either approach, OpenBaffle with "constant directivity" or Omni with "all around sound"... both approaches seem to work really well in almost any room...yes, BOTH of them!...........AND.... if they are similar in Freq response they can sound almost IDENTICAL!! ...freaky, huh?
SO...the sims that are run on "spatially coherent" designs do indeed seem to be very accurate predictors of how they will perform in real world rooms...and are MUCH easier to EQ to optimize in room performance.
NOW to connect with the theme of this thread, I would indeed say that "Flat is correct" but only when the recordings being used have not been doctored to sound good on speakers that are NOT "spatially coherent flat".
As a result, if you want your "spatially coherent, uniform acoustic power" speaker design to sound good on most recordings, it appears almost mandatory to dial in some gentle slope, i.e. a gradual drop with the highs being at a lower level than the lows. I'm not yet sure if it's better to go "continuous drop" or to have a HF shelf type of drop.
How do i know? Well, I have been working on some designs that take these things into account. I'll be happy to provide more details later as I have to get back to it... I'm planning to introduce them at RMAF, so I gotta get back to work!
And a big THANK YOU !! for their work to Geddes, Linkwitz and Krevkovsky.
Best Regards to All.
Hi to all, I' d like to add a few comments that may help bring together some of the loose strings in the "simulations are accurate vs no they are not debate".
1) The better simulators that are now in common use can be extremely accurate, within fractions of a dB in predicting response for one specific point. If the driver measurements are good, the accuracy of the simulator is such that you can almost dispense with verification measurements. (But this does not mean it will SOUND good, please read on).
2) Simulating/measuring for only the on-axis response can be fraught with peril, it rarely yields results which actually sound good to the majority of listeners.
3) Dr Toole's work showed the vast importance of having uniform Freq response on axis but ALSO off axis. He showed the AVERAGE hemispherical response needs to be very close to the on axis for it to be deemed good by a majority of listeners. (His studies were relative to direct radiator speakers, I don't believe he reported any results for open baffles or dipoles).
4) In support of Ben's experience, I have heard many, many designs (including my own ones early on) that had utterly GREAT response curves at 1m or 3m but which did NOT sound very good, but that was not because the simulations/measurements were wrong.... it was because their off axis response did not correlate well with the on axis.
It ain't the simulation, it's the overlooking of what Dr Toole pointed out, the AVERAGE response is at least as important. ESPECIALLY when you put it in a room!
In sum: the "SPATIAL coherence" of the speaker response is extremely important.
5) If the average power response is not fairly uniform and coherent with the on axis, the in room response and performance could be anywhere from lousy to fantastic, depending on how lucky we get with the combination.
Also, when attempting to eq speakers that are not "spatially coherent", it can become REALLY difficult to get any kind of in room measurement that correlates well with the listening experience. My guess would that this is what Ben has been referring to?
6) As Geddes with his controlled directivity speakers, and as Linkwitz and Krevkovsky have been showing with their OB (open baffle) designs, speakers with more uniform directionality generally sound much better in real world rooms.
Their designs DO measure well on axis, and the off axis responses also measure well, and more importantly their off axis or "spatial response" is very close to the on-axis.
Please note that these speakers generally sound very pleasing to almost all listeners, in a wide variety of rooms.
And they also tend to measure fairly well in many different positions in the room. Ask Kreskovsky if he thinks simulators are useful, and I believe he will tell you he most certainly does.
7) Ben, in relation to what you have described, I would venture the guess that when a speaker "looks great in simulations/measurements at 1 or 3 meters", but does not perform well at your listening position....well.... it is probably because too many (way too many!) designers overlook the average and off axis response and design only for on axis.
Please don't blame the simulations, they are usually quite accurate, but we need to know how to use them correctly! Methinks that what you are interpreting as an inaccuracy due to the simulations, is in fact an inaccuracy due to improper use of those sims, i.e. human error.
I've been studying these issues at depth, and believe like Linkwitz that the solution is to use open baffle or omni dispersion patterns to achieve "spatial coherence" (to coin a term) When the off axis characteristics are entirely coherent with the "on-axis" or direct response, i.e. they are "spatially coherent".
I never would have imagined this: either approach, OpenBaffle with "constant directivity" or Omni with "all around sound"... both approaches seem to work really well in almost any room...yes, BOTH of them!...........AND.... if they are similar in Freq response they can sound almost IDENTICAL!! ...freaky, huh?
SO...the sims that are run on "spatially coherent" designs do indeed seem to be very accurate predictors of how they will perform in real world rooms...and are MUCH easier to EQ to optimize in room performance.
NOW to connect with the theme of this thread, I would indeed say that "Flat is correct" but only when the recordings being used have not been doctored to sound good on speakers that are NOT "spatially coherent flat".
As a result, if you want your "spatially coherent, uniform acoustic power" speaker design to sound good on most recordings, it appears almost mandatory to dial in some gentle slope, i.e. a gradual drop with the highs being at a lower level than the lows. I'm not yet sure if it's better to go "continuous drop" or to have a HF shelf type of drop.
How do i know? Well, I have been working on some designs that take these things into account. I'll be happy to provide more details later as I have to get back to it... I'm planning to introduce them at RMAF, so I gotta get back to work!
And a big THANK YOU !! for their work to Geddes, Linkwitz and Krevkovsky.
Best Regards to All.
Jack Caldwell, Great post.
I actually assumed when talking about measurements most do understand that on axis alone is kind of meaningless in terms of "does it sound good". Polar response, power response, CSD, IMD all play a role in if a speaker will sound good or not.
I also agree with the Tilted slope for a more listenable sound since most people are use to that anyways. Of course I believe the tilted slope is more about room gain then forced speaker design. Some rooms will have more then others so this goes back to the idea that measurement and EQing is essential in room to improve the overall system response.
I actually assumed when talking about measurements most do understand that on axis alone is kind of meaningless in terms of "does it sound good". Polar response, power response, CSD, IMD all play a role in if a speaker will sound good or not.
I also agree with the Tilted slope for a more listenable sound since most people are use to that anyways. Of course I believe the tilted slope is more about room gain then forced speaker design. Some rooms will have more then others so this goes back to the idea that measurement and EQing is essential in room to improve the overall system response.
Grey area can be argued all day and night. There is not real answers in those areas because subjectivitiy pushes the topic around so much.
Black and White gets the job done. It has clarity and focus, there are definite conclusions and allows people to get closer to the truth.
I think everyone that is building or tweaking audio systems make their final decisions with their ears but I think some get a HUGE leg up by understanding what measurements (tools, etc) are available and maximize their usage.
YOu say you do everything by ear. You build speakers by ear, you EQ your system by Ear?
Several questions.
How do you know where the nulls are?
How do you know there is certain "ringing" issues in the boxes are?
How do you know if to tilt null several degrees in the vertical response?
I just can not see anyone being accurate enough with their ears. Granted I understand the point about just tweaking until you "like the sound" but unless you have measured you can never compare your final settings to professionally calibrated settings.
The goals of only audio science forums should be about going beyond what anyone likes to hear, its more about learning how to do the right measurements and learning all about the speaker issues that you will not notice with your ear.
not all simulators are the same
In my previous post I neglected to make a distinction between simulator types.
Exhibit A, sims such as Leap which are primarily concerned with "anechoic" type simulations and can predict the interaction with the crossovers filters to show the "final" result. Several of these are extremely accurate predictors of broadband measured anechoic response, within fractions of a dB.
Exhibit B, the sims from Martin J King which also include some of the room characteristics, and are primarily concerned with proper low frequency modeling.
These did not seem all that accurate at the beginning, but they have been getting closer and closer to the real thing as Martin has continued to refine his modeling. His work thus far is excellent, a true advancement in speaker/room interaction modeling, and in its current level does give fairly accurate data, enough to get a very good idea of how the speaker will perform on a global basis.
More later.
In my previous post I neglected to make a distinction between simulator types.
Exhibit A, sims such as Leap which are primarily concerned with "anechoic" type simulations and can predict the interaction with the crossovers filters to show the "final" result. Several of these are extremely accurate predictors of broadband measured anechoic response, within fractions of a dB.
Exhibit B, the sims from Martin J King which also include some of the room characteristics, and are primarily concerned with proper low frequency modeling.
These did not seem all that accurate at the beginning, but they have been getting closer and closer to the real thing as Martin has continued to refine his modeling. His work thus far is excellent, a true advancement in speaker/room interaction modeling, and in its current level does give fairly accurate data, enough to get a very good idea of how the speaker will perform on a global basis.
More later.
Very nice to have someone as sensible as Jack Caldwell contribute. I don't know as I disagree with anything Jack says, as far as he goes.
He says, simulations are pretty good, as far as they go. Unfortunately the gap between great 1 meter response and my chair is pretty vast, which leaves the simulation traces coming up short, as I've been saying.
And speaking of parameters, until recent times with DSP gadgets, our controls are largely irrelevant inheritances from tube circuit days as opposed to music or hearing parameters. If we were to buy speakers that were "Simulation Guaranteed Right" we still wouldn't have the knobs to properly correct the speakers for specific installations (and speaker designers today are too arrogant to give the user any knobs thinking their simulations produced perfect speakers for every room).
Related to this "flat" thread are a bunch of concurrent threads addressing equal loudness compensation. There "flat" takes on a dynamic meaning, maybe. So if simulations achieve some kind of "flat" they may still be far from modeling correct dynamic flat... and these simulations seem to be otherwise be clueless about human hearing. Like King's work, they can be infinitely painstaking about acoustics but butt-simple about hearing. They can endlessly fuss about some parameter without a good basis in evidence that it matters much.
(Aside: in something as complex as "good" in a speaker, I think some of the praise of this or that polar response as THE key to "good" is premature. A well-liked speaker will be better in all kinds of ways and I don't know about careful research that varies angle response systematically.)
In the Dr. Pangloss world of great simulations, there are just little corners of imperfection - like getting the manageable tech-fix issue of getting on-axis and the room-power response aligned. Bit of a joke there when you are dealing with the infinite variety of listening rooms, eh? In practice there are major shortcomings to speakers and systems and folks like us ESL devotees, hold tight to our dying breath to our many-flawed drivers, because we'd rather have those flaws than the perfect global power response that some people might think is the final frontier before perfection-land. My world-view, in those terms, just doesn't compute with Jack's narrow-focus world-view.
He says, simulations are pretty good, as far as they go. Unfortunately the gap between great 1 meter response and my chair is pretty vast, which leaves the simulation traces coming up short, as I've been saying.
And speaking of parameters, until recent times with DSP gadgets, our controls are largely irrelevant inheritances from tube circuit days as opposed to music or hearing parameters. If we were to buy speakers that were "Simulation Guaranteed Right" we still wouldn't have the knobs to properly correct the speakers for specific installations (and speaker designers today are too arrogant to give the user any knobs thinking their simulations produced perfect speakers for every room).
Related to this "flat" thread are a bunch of concurrent threads addressing equal loudness compensation. There "flat" takes on a dynamic meaning, maybe. So if simulations achieve some kind of "flat" they may still be far from modeling correct dynamic flat... and these simulations seem to be otherwise be clueless about human hearing. Like King's work, they can be infinitely painstaking about acoustics but butt-simple about hearing. They can endlessly fuss about some parameter without a good basis in evidence that it matters much.
(Aside: in something as complex as "good" in a speaker, I think some of the praise of this or that polar response as THE key to "good" is premature. A well-liked speaker will be better in all kinds of ways and I don't know about careful research that varies angle response systematically.)
In the Dr. Pangloss world of great simulations, there are just little corners of imperfection - like getting the manageable tech-fix issue of getting on-axis and the room-power response aligned. Bit of a joke there when you are dealing with the infinite variety of listening rooms, eh? In practice there are major shortcomings to speakers and systems and folks like us ESL devotees, hold tight to our dying breath to our many-flawed drivers, because we'd rather have those flaws than the perfect global power response that some people might think is the final frontier before perfection-land. My world-view, in those terms, just doesn't compute with Jack's narrow-focus world-view.
Again, I don't think we are are giving Martin the credit he is due and I object to the statement "These did not seem all that accurate at the beginning". His software was completed two years before those papers were written. He's merely documenting the research process he went through and any inaccurate calculations were the prior work of others, not Martin's own.
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speaker/sim vs room vs eq
Hi Ben,
I'd like to give just a little bit more of an overview to the issue you were bringing up at the end of your previous post, i.e. the room variability issue. Yes rooms are infinitely variable and it seems pretty much impossible (improbable?) to mathematically define all of the variables.
BUT...
when the speakers being used have very uniform directionality characteristics, whether because it's a well designed OB like the new NaO offering and a few others, or because it's a well designed omni like what I'm about to show at RMAF, much of the EFFECT of the room variability diminishes.
With "regular" loudspeakers (i.e. most direct radiators) where the power response is changing with frequency, the room has a much greater PERCEIVED influence. Their timbrel image is very different off axis vs. on axis, and so the reflected images have a hugely different timbrel signature.
It's a psychoacoustic thing related to non-coherent timbrel images bouncing around the room vs coherent ones.
Let me elaborate on this just a bit: with either the uniform directionality speakers or the omni's, the ACTUAL room resonances are NOT disappearing, we just hear them much less than before...
Why? Because the timbrel images of the direct response vs the reflected responses are much more similar in frequency and in time. They are timbre-coherent. And this makes it much easier for our hearing to "ignore the room" and focus on the main image.
The perceived difference is huge. So much so that with "equi-timbrel spatially coherent" speakers (such as the ones I'm designing) it is usually not necessary to EQ for the room at all, from about 120Hz on up. (We still may need to correct for the room's low bass response though)
OK, so where does the sim come in?
Well, with the OB or Omni as the platform, a good first step would be to "anechoically sim-design" the speakers to obtain get uniform freq response and power response. This gives us good timbrel image coherence as the INPUT to the room.
When there is almost no timbrel discontinuity, the room effect is less perceivable to your auditory system, as it "locks" onto the main image and screens out or "disconnects" from the room sound. It can actually sound like the speakers and the room have "disappeared" and with good recordings you often get an amazingly real sounding facsimile of the acoustic space on the recording. A hologram that sounds astonishingly real!
AND.... when timbrel images are coherent, it also becomes much EASIER to eq in a way that correlates well with the measurements near or at the listening location.
So, replying to your question:
1) the sim is extremely useful to provide the proper equi-timbrel input into the room.
2) If the design is "equi-timbrel" in space, the room is less of an issue.
3) If the design is "equi timbrel" it is also easier to measure and EQ at the listening location, and come up with valid correlation between measured and auditory impressions.
BTW, with the equipment you have listed, I would wager to say you have come close to what I've described for the OB designs!
Your Dayton-Wrights, are fairly directional at low, mid and higher frequencies... being ESL "open baffle" they are fairly directional in the lower frequencies, and so they may come closer to the "equi timbrel" controlled directivity criteria described above. (way ahead of most direct radiator speakers, that's for sure!)
Their interaction with the room is such that the side to side and floor to ceiling axial modes of the room remain virtually unexcited. They are also very "flat frequency response".
Because your DaytonWright speakers go farther than most in meeting the criteria for a good controlled directionality OB, what you get at your listening position is more of the timbre correct variety, and this indeed makes it much easier to EQ by ear and get pleasing results...
And with a setup such as yours, it may well be that what sounds good would also measure (and simulate) fairly well.
And now to argue against the contention that you "can't do it by ear". With OB speakers similar to what Ben has (DaytonWright ESLs), it is INDEED possible to eq by ear and get results that would correlate fairly well with what we could attain by measuring. But I would suggest that this holds true only for speakers with truly well controlled dispersion or true omnis. With variable directionality systems it's possible but not probable!
So there you have it, the world view issue may not be as far apart as some have thought it was, it's just that the spatial/timbrel uniformity + psychoacoustics combo plays a much larger role in this than most people have heretofore realized.
A reductive measurements approach, as part of a well thought out plan that includes a deeper understanding of speaker/room interactions AND psychoacoustics can indeed deliver a solution that satisfies on the broad scale level that Ben prefers to operate on.
So Ben, in your unique setup, it may well be that the system is performing admirably with nothing but tuning by ear, but that is probably because the speakers you are using are closer to the OB/uniform directivity criteria.
If you are able to come to RMAF October 15/16/17, you will be able to hear some of the solutions we are proposing for this issue. We think they sound pretty good. It would be great to get your impressions. Look for us as Holographic Audio Arts in Room 8030.
All the Best
Hi Ben,
I'd like to give just a little bit more of an overview to the issue you were bringing up at the end of your previous post, i.e. the room variability issue. Yes rooms are infinitely variable and it seems pretty much impossible (improbable?) to mathematically define all of the variables.
BUT...
when the speakers being used have very uniform directionality characteristics, whether because it's a well designed OB like the new NaO offering and a few others, or because it's a well designed omni like what I'm about to show at RMAF, much of the EFFECT of the room variability diminishes.
With "regular" loudspeakers (i.e. most direct radiators) where the power response is changing with frequency, the room has a much greater PERCEIVED influence. Their timbrel image is very different off axis vs. on axis, and so the reflected images have a hugely different timbrel signature.
It's a psychoacoustic thing related to non-coherent timbrel images bouncing around the room vs coherent ones.
Let me elaborate on this just a bit: with either the uniform directionality speakers or the omni's, the ACTUAL room resonances are NOT disappearing, we just hear them much less than before...
Why? Because the timbrel images of the direct response vs the reflected responses are much more similar in frequency and in time. They are timbre-coherent. And this makes it much easier for our hearing to "ignore the room" and focus on the main image.
The perceived difference is huge. So much so that with "equi-timbrel spatially coherent" speakers (such as the ones I'm designing) it is usually not necessary to EQ for the room at all, from about 120Hz on up. (We still may need to correct for the room's low bass response though)
OK, so where does the sim come in?
Well, with the OB or Omni as the platform, a good first step would be to "anechoically sim-design" the speakers to obtain get uniform freq response and power response. This gives us good timbrel image coherence as the INPUT to the room.
When there is almost no timbrel discontinuity, the room effect is less perceivable to your auditory system, as it "locks" onto the main image and screens out or "disconnects" from the room sound. It can actually sound like the speakers and the room have "disappeared" and with good recordings you often get an amazingly real sounding facsimile of the acoustic space on the recording. A hologram that sounds astonishingly real!
AND.... when timbrel images are coherent, it also becomes much EASIER to eq in a way that correlates well with the measurements near or at the listening location.
So, replying to your question:
1) the sim is extremely useful to provide the proper equi-timbrel input into the room.
2) If the design is "equi-timbrel" in space, the room is less of an issue.
3) If the design is "equi timbrel" it is also easier to measure and EQ at the listening location, and come up with valid correlation between measured and auditory impressions.
BTW, with the equipment you have listed, I would wager to say you have come close to what I've described for the OB designs!
Your Dayton-Wrights, are fairly directional at low, mid and higher frequencies... being ESL "open baffle" they are fairly directional in the lower frequencies, and so they may come closer to the "equi timbrel" controlled directivity criteria described above. (way ahead of most direct radiator speakers, that's for sure!)
Their interaction with the room is such that the side to side and floor to ceiling axial modes of the room remain virtually unexcited. They are also very "flat frequency response".
Because your DaytonWright speakers go farther than most in meeting the criteria for a good controlled directionality OB, what you get at your listening position is more of the timbre correct variety, and this indeed makes it much easier to EQ by ear and get pleasing results...
And with a setup such as yours, it may well be that what sounds good would also measure (and simulate) fairly well.
And now to argue against the contention that you "can't do it by ear". With OB speakers similar to what Ben has (DaytonWright ESLs), it is INDEED possible to eq by ear and get results that would correlate fairly well with what we could attain by measuring. But I would suggest that this holds true only for speakers with truly well controlled dispersion or true omnis. With variable directionality systems it's possible but not probable!
So there you have it, the world view issue may not be as far apart as some have thought it was, it's just that the spatial/timbrel uniformity + psychoacoustics combo plays a much larger role in this than most people have heretofore realized.
A reductive measurements approach, as part of a well thought out plan that includes a deeper understanding of speaker/room interactions AND psychoacoustics can indeed deliver a solution that satisfies on the broad scale level that Ben prefers to operate on.
So Ben, in your unique setup, it may well be that the system is performing admirably with nothing but tuning by ear, but that is probably because the speakers you are using are closer to the OB/uniform directivity criteria.
If you are able to come to RMAF October 15/16/17, you will be able to hear some of the solutions we are proposing for this issue. We think they sound pretty good. It would be great to get your impressions. Look for us as Holographic Audio Arts in Room 8030.
All the Best
Credit for Martin J King
Hi Dennis, when I wrote
snip
they have been getting closer and closer to the real thing as Martin has continued to refine his modeling. His work thus far is excellent, a true advancement in speaker/room interaction modeling, and in its current level does give fairly accurate data, enough to get a very good idea....
snip
in what way does THAT seem like I'm not giving him enough credit?
I thought I was indeed explaining to Ben that Martin's early work was already pretty great, but it has gotten much more accurate!
If words like "a true advancement in speaker/room interaction modeling" aren't good enough, what words would you suggest I employ?
And I still stand by my comment that his current offering is much more accurate than his earlier ones, and I think Martin would agree with that.
BTW, while I've been commenting mostly about his OB sims, his models for T-lines and TQWTL are the best I've seen by far.
Best regards, Jack
Hi Dennis, when I wrote
snip
they have been getting closer and closer to the real thing as Martin has continued to refine his modeling. His work thus far is excellent, a true advancement in speaker/room interaction modeling, and in its current level does give fairly accurate data, enough to get a very good idea....
snip
in what way does THAT seem like I'm not giving him enough credit?
I thought I was indeed explaining to Ben that Martin's early work was already pretty great, but it has gotten much more accurate!
If words like "a true advancement in speaker/room interaction modeling" aren't good enough, what words would you suggest I employ?
And I still stand by my comment that his current offering is much more accurate than his earlier ones, and I think Martin would agree with that.
BTW, while I've been commenting mostly about his OB sims, his models for T-lines and TQWTL are the best I've seen by far.
Best regards, Jack
More about Martin's sims
I' ve been a user of Martin's TQWLT sims for several years, so my previous comments were not based on his papers, rather on what I found in my experiments.
As they stand now, Martin's simulators are phenomenally useful. So there!
I' ve been a user of Martin's TQWLT sims for several years, so my previous comments were not based on his papers, rather on what I found in my experiments.
As they stand now, Martin's simulators are phenomenally useful. So there!
And the "spatial/timbrel non-coherence" is what makes
the loudspeaker itself detectable as a sound source having
an own "character", may it be pleasing or disagreeable to
one or the other listener.
It will hamper the stereophonic illusion, by drawing
attention to the speakers. Phantom sources will blurr
like an image on a silent water surface, when a stone
is dropped into the water ...
Best
Sorry Jack, I misunderstood what you were saying. I still had my back up about Ben's previous unfair Martin bashing and didn't read carefully enough. 🙂
Aside from the tempers, very good thread.
I would like to add that I think SL and others mentioned here have made quite significant contributions that are very often significantly understated... so a big thank you SL and everyone else who has been so generous sharing their wealth of knowledge. I also think everyone, on this tread and elsewhere in these forums, have made many useful observations that many of use have learned a lot from. Sims, testing data, listening observations and so on have all have been of value to a great many of us. I suspect that who might pretend they haven't been learning from each other just have big egos.
With regard to the question of the possible notion of an optimal frequency response curve; I would offer that perhaps it is simply easier for us to compare notes using the gated/free field response curves. Most of you probably don't care as much about the way some room might sound nearly as much as you are interested in how a particular speaker design concept might sound. But at the same time, having an idea what the room might be adding to the response is also helpful because that is where we all prefer to listen to them and this is what we base our subjective experience upon.
Many of have to contend with a decidedly non-scientific WAF, so the perfect room just isn't a reality. As a result, it seems many have moved toward speakers that can minimize room effects and in the end we rely on our subjective evaluations. At this time, I've settled on a downward slope very much like that described by SL. To me and my ears, I feel it provides me with a more realistic "stage" than my previously "flat" setup. Obviously, your mileage will vary depending on a great number of factors.
But I've always found it particularly helpful to have other people listen to the speakers I've built and be open to their feedback. Sometimes they can notice little things that I have not. Perhaps our brains become too acclimatized to our rooms and setup. I have a relative who is a recording engineer and when he comes by, I ask him to listen to my system and compare his mental notes of what he heard in the studio to what he hears in my room with my speakers. So the next time I can have a recording engineer come over for a listen, it is entirely possible that I'll end up making a few changes to see if I can find something that I might like a little better.
It sounds like SL gets his kicks out of "building a transducer". To me, the experience was very different... more like "building an instrument". But somehow I've ended up with something that looks alot like what SL calls a transducer. 😉
Certainly as I continue to pursue the hobby I'll try other ideas as well.
In the end, as others have said, it will always depends on what you think is best and this will be most pleasing to you. I think the only thing we can all agree on is that building our own gear provides great enjoyment
Josh
I would like to add that I think SL and others mentioned here have made quite significant contributions that are very often significantly understated... so a big thank you SL and everyone else who has been so generous sharing their wealth of knowledge. I also think everyone, on this tread and elsewhere in these forums, have made many useful observations that many of use have learned a lot from. Sims, testing data, listening observations and so on have all have been of value to a great many of us. I suspect that who might pretend they haven't been learning from each other just have big egos.
With regard to the question of the possible notion of an optimal frequency response curve; I would offer that perhaps it is simply easier for us to compare notes using the gated/free field response curves. Most of you probably don't care as much about the way some room might sound nearly as much as you are interested in how a particular speaker design concept might sound. But at the same time, having an idea what the room might be adding to the response is also helpful because that is where we all prefer to listen to them and this is what we base our subjective experience upon.
Many of have to contend with a decidedly non-scientific WAF, so the perfect room just isn't a reality. As a result, it seems many have moved toward speakers that can minimize room effects and in the end we rely on our subjective evaluations. At this time, I've settled on a downward slope very much like that described by SL. To me and my ears, I feel it provides me with a more realistic "stage" than my previously "flat" setup. Obviously, your mileage will vary depending on a great number of factors.
But I've always found it particularly helpful to have other people listen to the speakers I've built and be open to their feedback. Sometimes they can notice little things that I have not. Perhaps our brains become too acclimatized to our rooms and setup. I have a relative who is a recording engineer and when he comes by, I ask him to listen to my system and compare his mental notes of what he heard in the studio to what he hears in my room with my speakers. So the next time I can have a recording engineer come over for a listen, it is entirely possible that I'll end up making a few changes to see if I can find something that I might like a little better.
It sounds like SL gets his kicks out of "building a transducer". To me, the experience was very different... more like "building an instrument". But somehow I've ended up with something that looks alot like what SL calls a transducer. 😉
Certainly as I continue to pursue the hobby I'll try other ideas as well.
In the end, as others have said, it will always depends on what you think is best and this will be most pleasing to you. I think the only thing we can all agree on is that building our own gear provides great enjoyment
Josh
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Jack - any lessons from RMAF? (Well, I did pass once through Denver with wife on a memorable motorcycle trip to LA... but Oct is a bit late in the season!)
The consequences of room modes, cancellations (a related but separate matter as far as a mic is concerned), and room gain (urban myth?) are really complicated. Just looked at a comparison of a mic test with one of those room-mode simulators and (like my own recent simple efforts) straaaange bumps where dips should be, shifts in frequency, etc. So, all credit to King if he is making progress taming these factors in theory.
Since the room modes do not go away without serious acoustic interventions, it would be good to catalog the tricks to combat their effects*. Perhaps another shot at explaining your "equi-timbrel spatially coherent" speakers would help many of us.
Thanks.
* You mentioned some virtues inherent in the meter-square dipole curved Dayton-Wrights. Yes, I'm lucky but also stuffed arm-chairs, bookcases, clothes closets (filled with thick motorcycle winter clothes), thick carpet, and now a giant OB mid-wall sub to complement the korner Klipsch. Dead is good, in home music rooms.
The consequences of room modes, cancellations (a related but separate matter as far as a mic is concerned), and room gain (urban myth?) are really complicated. Just looked at a comparison of a mic test with one of those room-mode simulators and (like my own recent simple efforts) straaaange bumps where dips should be, shifts in frequency, etc. So, all credit to King if he is making progress taming these factors in theory.
Since the room modes do not go away without serious acoustic interventions, it would be good to catalog the tricks to combat their effects*. Perhaps another shot at explaining your "equi-timbrel spatially coherent" speakers would help many of us.
Thanks.
* You mentioned some virtues inherent in the meter-square dipole curved Dayton-Wrights. Yes, I'm lucky but also stuffed arm-chairs, bookcases, clothes closets (filled with thick motorcycle winter clothes), thick carpet, and now a giant OB mid-wall sub to complement the korner Klipsch. Dead is good, in home music rooms.
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