The question I asked & you dodged - have you ever designed & conducted a DBT? If you haven't done this then you can just post exactly all the criteria you consider will qualify it as scientifically rigorous? Hint, a link will not do & will be considered just dodging the question again.
No.
No - as I have no experience of designing audio tests or any other subjective tests any criteria I propose would be just guesswork. There are people on here with extensive experience of this, so I will leave such matters to them.
n/a.
I didn't dodge your question. I merely regarded it as irrelevant. Is it now necessary to have experience of designing and conducting DBT before it is permitted to make any comment on them or related matters? This is a most unscientific way of approaching things; in real science the truth of a statement does not depend on who said it.
I thought we were having a discussion, not an interrogation.
No - as I have no experience of designing audio tests or any other subjective tests any criteria I propose would be just guesswork. There are people on here with extensive experience of this, so I will leave such matters to them.
n/a.
I didn't dodge your question. I merely regarded it as irrelevant. Is it now necessary to have experience of designing and conducting DBT before it is permitted to make any comment on them or related matters? This is a most unscientific way of approaching things; in real science the truth of a statement does not depend on who said it.
I thought we were having a discussion, not an interrogation.
I see, so you are suggesting a test that you claim is scientifically rigorous but know nothing about it! Not a very scientific way of approaching things!
I asked for DBT advice on this forum before I conducted one but soon realised, after reading a number of the replies, that it would be impossible to satisfy the criteria demanded unless one had a big budget or could convince a university to conduct it on one's behalf.
My point is that anything which isn't scientifically rigorous is actually no better than anecdotal evidence. A view you will no doubt concur with based on your requirement for such rigour.
I asked for DBT advice on this forum before I conducted one but soon realised, after reading a number of the replies, that it would be impossible to satisfy the criteria demanded unless one had a big budget or could convince a university to conduct it on one's behalf.
My point is that anything which isn't scientifically rigorous is actually no better than anecdotal evidence. A view you will no doubt concur with based on your requirement for such rigour.
It's not nearly as difficult and expensive as you fear. My last several rounds cost next to zero. They DO take some time and effort, but nothing overwhelming if you decide that it's something you actually want to do. Jack's tests, for example, could easily be made rigorous, though he hasn't followed up on my offer to help him design it.
Stay tuned for the next issue of Linear Audio.
Stay tuned for the next issue of Linear Audio.
I used the phrase "scientifiically structured". You have introduced the idea of rigour. You now claim that I "know nothing" about DBT, because I refuse to submit to your interrogation. It may well be true, as you say, that rigorous DBT requires a lot of money and resources. I am not suggesting any test; it is others who are suggesting tests, and I am merely making some remarks about what I perceive as a cultural clash between these tests and the tests which they normally prefer.
I disagree with your claim that there is nothing between full DBT and anecdotes. It seems to me that there is a spectrum there, with wilder claims requiring better experimental support.
It feels like I have accidentally touched one of your hot buttons. Please calm down, and stop jumping to conclusions.
I disagree with your claim that there is nothing between full DBT and anecdotes. It seems to me that there is a spectrum there, with wilder claims requiring better experimental support.
It feels like I have accidentally touched one of your hot buttons. Please calm down, and stop jumping to conclusions.
So what is your criteria for testing? Rigour is unimportant?
What's the point of experimental support that has no rigour - how is it any better than "wilder claims". I can't fathom your logic?
Don't worry, I'm using a GSR to provide me with feedback on my internal stress levels
Why all this lurching from one extreme to the other? First you accuse me of requiring rigour (a word I did not use), now you accuse me of dismissing rigour. Do you live in a binary world where everything has to be either one extreme or the other? Maybe that is why you can't fathom my logic. I refuse to play your games.jkeny said:
Ah, you find your position indefensible - fine! Maybe you should be less bullish about what tests people can or should do? As you have already stated "any criteria I propose would be just guesswork" & even refuse to say what you consider is important in testing
Not my first choice for clever marketing!
And you know what else? Further validating the first set of my findings would even make sense from the long-term commercial point of view, as it would add to the "legitimacy" of the final product.
However, I feel that I've proven the point with sufficient rigor for my purposes. So, I jumped in and built product to meet the subliminal criteria I developed, but also performs and measures extremely well by conventional standards. But I overspent. Now my focus has to be on growing the business to try and cover my expenses, then to recover my investment, and then hopefully a little more.
Then, at a later time, when time and finances permit, I'm all for providing the controlled follow-up you suggest is necessary.
However:
- At the moment my main priority is to convince paying clients to listen to the product. The few that have have come to listen to it have liked it and purchased it. Now I need more exposure to sell more products.
But, to be honest, I didn't come here thinking this forum is going to generate many (or any) sales. I thought maybe I could contribute something of value and hopefully help us all get a more complete picture of what objective measurements correlate with a better listening experience.
Jan, if clever marketing is to offer information to people who are not likely buyers, but who could take that information, do their own tests, and possibly become competitors, then yes, I guess it's marketing.
Only, could you please please tell me what is so clever about it?
Hi Jan, yes, of course it would great to button it all down in a way that's fully accepted as you suggest. And, it would even be nice to get a great reputation like that of Linkwitz or Geddes, (who last time I checked, also appear to have commercial interests in selling their products, and have much presence on these forums).
And you know what else? Further validating the first set of my findings would even make sense from the long-term commercial point of view, as it would add to the "legitimacy" of the final product.
However, I feel that I've proven the point with sufficient rigor for my purposes. So, I jumped in and built product to meet the subliminal criteria I developed, but also performs and measures extremely well by conventional standards. But I overspent. Now my focus has to be on growing the business to try and cover my expenses, then to recover my investment, and then hopefully a little more.
Then, at a later time, when time and finances permit, I'm all for providing the controlled follow-up you suggest is necessary.
However:
- At the moment my main priority is to convince paying clients to listen to the product. The few that have have come to listen to it have liked it and purchased it. Now I need more exposure to sell more products.
But, to be honest, I didn't come here thinking this forum is going to generate many (or any) sales. I thought maybe I could contribute something of value and hopefully help us all get a more complete picture of what objective measurements correlate with a better listening experience.
Jan, if clever marketing is to offer information to people who are not likely buyers, but who could take that information, do their own tests, and possibly become competitors, then yes, I guess it's marketing.
Only, could you please please tell me what is so clever about it?
Good info, thanks
This is particularly relevant to the use of force-canceling in speakers. Floor-borne vibration, conducting through the bones in the body and then to the hearing apparatus is a major source of "coloration" even when it isn't producing much of an audible acoustic wave, and more so when it is.
It is especially problematic (from a perceptible effect) when it arrives at our hearing/processing before the acoustic wave (from the speaker), and thus creates disturbances in our localization process.
It's no surprise more and more speaker designers are opting to use force-canceling woofers and subs. It sounds much better, and from the subliminal point of view, it allows for easier, less stressful localization of the apparent image.
This corroborates some of what we've found in our research.
This is particularly relevant to the use of force-canceling in speakers. Floor-borne vibration, conducting through the bones in the body and then to the hearing apparatus is a major source of "coloration" even when it isn't producing much of an audible acoustic wave, and more so when it is.
It is especially problematic (from a perceptible effect) when it arrives at our hearing/processing before the acoustic wave (from the speaker), and thus creates disturbances in our localization process.
It's no surprise more and more speaker designers are opting to use force-canceling woofers and subs. It sounds much better, and from the subliminal point of view, it allows for easier, less stressful localization of the apparent image.
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Probably so...
The big advantage of a concrete slab on hard ground is that it does not generate as much acoustical output as a suspended wood or concrete floor, which will resonate and "sing". (or is it dance?)
Suspended concrete will probably resonate at a lower frequency than wood.
Otherwise, both Wood and Concrete (supended or in slabs) slabs, whether suspended or laid on a bed of compacted rocks on the ground, transmit the energy much faster than air:
quoting from Speed of Sound in some common Solids
the speed of sound through concrete is in the range of 3200 to 3600 meters per second, similar to that of wood & hardwood which is between 3200 and 3960 m/s.....the attenuation is very low, meaning most of the conducted energy gets through.
For bone: A Method for the Measurement of Acoustic Impedance and Speed of Sound in a Smal
I quote from their study: "The speed of sound propagated through bone-conduction is about 3780± 250 m/s, and attenuation constant; 2.70± 0.50 Np/m."
The attenuation of bone itself is very low, but we have to factor in the joints, etc. so by the time it reaches our auditory apparatus, it has somewhat attenuated... but I haven't yet found studies that quantify it.
So, gathering wood or concrete and bone, we have a conducted wave velocity which is roughly X10 faster than the acoustic wave.
If you are sitting at 3.44 m from your speakers, the acoustic wave will get to your ears in 10mS.
If we assume the conducted wave speed between floor and body/bones is 3440 meters per second, and the conducted wave has a path length of 3.44 + 1.72 m (internal body length from feet to ears), it will arrive in 5.12/3440= 1.5mS, roughly 8.5 mS before the acoustic wave.
8.5mS.....that's a BIG difference in arrival time !
Granted, there will be an amplitude difference between the initial conducted wave and the initial direct acoustic wave...
but the acoustic wave will arrive attenuated by about -10dB, while the conducted wave will not have much attenuation at all...
i.e. if they start with a 60dB difference, they will arrive with maybe 50 dB difference, and perhaps much less than that if the floor has any major peaks in its conducted frequency response.... it's not uncommon to see a 20dB resonant peak... so, depending on the material, weight and construction, in practice it's pretty easy to get a mechanically conducted signal that is only 30 dB or so lower amplitude than the acoustic wave.
And since the conducted wave arrives so much earlier, its audibility/perceptibility increases substantially.
In sum:
The concrete slab, laid on the ground will still have a similar arrival time, but because it is much less resonant, and because the substrate under it (compacted rocks, gravel and ground) exerts some damping, its audible effects will be much less obvious than the suspended floors.
So, yes your room would have a built-in advantage over those with suspended floors.
Subjectively, using our H1 speakers which do not have force cancellation, the sound is much clearer in rooms with on-ground concrete slab than in rooms with suspended floors.
Conversely when we use our (force canceling) H3 speakers in the same rooms, the floor contribution is minimized and the clarity of reproduction is much higher in either type of room. It's a very substantial difference in clarity in both cases, but especially so in rooms with suspended floors. THe H3 sounds remarkably similar in any room, while the H1 sound is more variable. Most of this is due to conduction!
The biggest difference on the H3 is heard with percussive bass transients, where the impact is subjectively much greater and much more "surprising" due to the lack of floor-borne "advance notice".
This difference would apply to any force canceling system, not just ours. Except we have designed the force canceling to go way up in frequency, and the subjective benefits are very good.
Yes and no.
The big advantage of a concrete slab on hard ground is that it does not generate as much acoustical output as a suspended wood or concrete floor, which will resonate and "sing". (or is it dance?
)Suspended concrete will probably resonate at a lower frequency than wood.
Otherwise, both Wood and Concrete (supended or in slabs) slabs, whether suspended or laid on a bed of compacted rocks on the ground, transmit the energy much faster than air:
quoting from Speed of Sound in some common Solids
the speed of sound through concrete is in the range of 3200 to 3600 meters per second, similar to that of wood & hardwood which is between 3200 and 3960 m/s.....the attenuation is very low, meaning most of the conducted energy gets through.
For bone: A Method for the Measurement of Acoustic Impedance and Speed of Sound in a Smal
I quote from their study: "The speed of sound propagated through bone-conduction is about 3780± 250 m/s, and attenuation constant; 2.70± 0.50 Np/m."
The attenuation of bone itself is very low, but we have to factor in the joints, etc. so by the time it reaches our auditory apparatus, it has somewhat attenuated... but I haven't yet found studies that quantify it.
So, gathering wood or concrete and bone, we have a conducted wave velocity which is roughly X10 faster than the acoustic wave.
If you are sitting at 3.44 m from your speakers, the acoustic wave will get to your ears in 10mS.
If we assume the conducted wave speed between floor and body/bones is 3440 meters per second, and the conducted wave has a path length of 3.44 + 1.72 m (internal body length from feet to ears), it will arrive in 5.12/3440= 1.5mS, roughly 8.5 mS before the acoustic wave.
8.5mS.....that's a BIG difference in arrival time !
Granted, there will be an amplitude difference between the initial conducted wave and the initial direct acoustic wave...
but the acoustic wave will arrive attenuated by about -10dB, while the conducted wave will not have much attenuation at all...
i.e. if they start with a 60dB difference, they will arrive with maybe 50 dB difference, and perhaps much less than that if the floor has any major peaks in its conducted frequency response.... it's not uncommon to see a 20dB resonant peak... so, depending on the material, weight and construction, in practice it's pretty easy to get a mechanically conducted signal that is only 30 dB or so lower amplitude than the acoustic wave.
And since the conducted wave arrives so much earlier, its audibility/perceptibility increases substantially.
In sum:
The concrete slab, laid on the ground will still have a similar arrival time, but because it is much less resonant, and because the substrate under it (compacted rocks, gravel and ground) exerts some damping, its audible effects will be much less obvious than the suspended floors.
So, yes your room would have a built-in advantage over those with suspended floors.
Subjectively, using our H1 speakers which do not have force cancellation, the sound is much clearer in rooms with on-ground concrete slab than in rooms with suspended floors.
Conversely when we use our (force canceling) H3 speakers in the same rooms, the floor contribution is minimized and the clarity of reproduction is much higher in either type of room. It's a very substantial difference in clarity in both cases, but especially so in rooms with suspended floors. THe H3 sounds remarkably similar in any room, while the H1 sound is more variable. Most of this is due to conduction!
The biggest difference on the H3 is heard with percussive bass transients, where the impact is subjectively much greater and much more "surprising" due to the lack of floor-borne "advance notice".
This difference would apply to any force canceling system, not just ours. Except we have designed the force canceling to go way up in frequency, and the subjective benefits are very good.
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Well, let's take that farther. You have a concrete slab on the ground (the way almost all houses in California and this part of Texas, at least, are built). So the transverse component of any vibration will be near zero- the flexure is constrained. What's the magnitude of the remaining longitudinal component? How will that couple to the listener?
Putting aside the advertising, what data do you have to support the notion of vibration from the speakers being coupled to the listener?
Putting aside the advertising, what data do you have to support the notion of vibration from the speakers being coupled to the listener?
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