So then finally got your high bit rate super tweeted ultrasonic stereo going.
Is this thing in your room by means of your partner's hobby.
Ecuadorian Cactus Absorbs Ultrasound, Enticing Bats to Flowers | The Scientist Magazine(R)
Seriously, does anyone realize how much ultrasound is attenuated in air and pretty much impossible to generate in anything but a quite restricted beam.
Is this thing in your room by means of your partner's hobby.
Ecuadorian Cactus Absorbs Ultrasound, Enticing Bats to Flowers | The Scientist Magazine(R)
Seriously, does anyone realize how much ultrasound is attenuated in air and pretty much impossible to generate in anything but a quite restricted beam.
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People hearing things that nobody else can hear reminds me of people with a firm believe that they are clairvoyant and see things that others don’t.
The Dutch police have asked numerous times for their assistance in murdercases where they did not have a single clue.
However, it never ever resulted in solving a case !
Hans
The Dutch police have asked numerous times for their assistance in murdercases where they did not have a single clue.
However, it never ever resulted in solving a case !
Hans
Why?
The smaller number just seems more realistic ime......conjecture of course.
Yes, I’ve come to realize my bias against bias.....therefore I am not bias free!
Edit.....
Hans I’m not saying nobody else hears these things, it just seems correct to me there is a small percent that may have a better perception,connection, interpretation.......whatever one wants to label it as.
Some have natural affinities in this area that when nurtured can turn into a skill set......I’m sure most others could be trained, some others probably not.
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Thanks Dreamth for bringing this up. I must admit to INTRODUCING the AD712 to the Parasound engineers by both recommending it for servos in many products, and originally, (more than 25 years ago) recommended it for the INPUT BUFFER for the HCA2200 power amp, my first amp contribution to Parasound. It FAILED in that application, and perhaps any similar op amp would also as a substitute for the input buffer. Once this design failed, and I designed out the IC op amp in the input buffer, and used an alternate discrete approach, I don't remember recommending the AD711,712 for any in path audio application since. Now, what I was showing in what you put up is how to NOT design a preamp, which includes lots of cap coupled IC's, and indifferent selection of the IC type.
This was done by engineers that I have never met personally. Nor had any direct communication with.
Of course, I was completely behind using the AD712, initially. But once I had a problem, I would not recommend it further for anything but servos. Was I unfair about this? Maybe. But I was showing an example of MID-FI design, not what I have actually designed, even for Parasound.
This was done by engineers that I have never met personally. Nor had any direct communication with.
Of course, I was completely behind using the AD712, initially. But once I had a problem, I would not recommend it further for anything but servos. Was I unfair about this? Maybe. But I was showing an example of MID-FI design, not what I have actually designed, even for Parasound.
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Story is, it FAILED because a review chimp from a well known magazine popped the lid, got horrified by the eight legged monster he saw inside, and as a result he chastised the entire amp. There was never any technical argument against that IC input buffer, but then of course, magazine review chimps are the guiding light of any audio professional involved in high end audio development.
That assumes a normal distribution, which depends on the population, and a decent amount on confounding variables. I did a quick look at the normality of athletic performances as a proxy to hearing and this blog highlights some of the issues at play when looking at populations.
OR in an OB World: The Normal Density Is Not A Fractal
People are defined more by their failures than by their successes ...as only through repeated failures you learn how to be successful? Didn't you hear that before?
Now i'm curious why you're actually loosing your time in this vanity war?Are you having so much to gain out of it?
The real problem that you have is that you're loosing yourself here. You're not the only one though...
No, Syn08, I don't think that the amp was subjectively reviewed AFTER looking inside. The main reviewer told me this, and I believe him. Certainly more than you
In fact, after this fiasco, where I almost got fired, I removed that AD712 from MY personal power amp and it improved the sound quality. It was easy to just jumper it out. Others, including Brian Cheney, who I shared an office with at the time, and my associate Carl Thompson, also tried the change, and got an improvement.
In fact, after this fiasco, where I almost got fired, I removed that AD712 from MY personal power amp and it improved the sound quality. It was easy to just jumper it out. Others, including Brian Cheney, who I shared an office with at the time, and my associate Carl Thompson, also tried the change, and got an improvement.
To be a little more serious than usual, let me tell you that we live in a human society and invite you to think about what it entails.
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I'd even go deeper...I never heard of a properly designed amplifier to fail because of an input capacitor ...that slew rate misleading story it's finding a way in the "high end" mythical audio world every now and then when the high-end reviewers that spent 3 years in a prestigious literature university starts writing about electronics...
I told that before just by quoting others with a better CV than mine in electronics : it's not too much physics about that, but a sinus wave signal slew rate is maximum at zero crossing where the capacitance has no distortions and it's minimum at the signal's maximum amplitude so again, it's impossible to have slew rate induced distortions due to capacitors.
Virtually every audio fet transistor has a big capacitance on the input and it's considered beneficial for circuits stability in general.
At the time JC-Otalla study came on the market the higher value capacitor's quality was really bad compared to today's technology, yet if somebody took the decision to use a "highly praised audiophile capacitor" in their designs than that might be just another Vanity fair...
On the other hand i recall JC designs having fet input...so capacitors weren't needed at all while you could use very low capacitance anyway, and for low values there were always good capacitors on the market.
The most linear amplifier i heard (0.005% 110w/ 4ohm/20hz-20khz) had an AC/DC switch and i couldn't hear a damn thing in switching between the two positions , nor the technical reviewers in Netherland could measure anything different.
I am using capacitors in any of my amps and can't hear a difference . I have a Realistic STA2250 amp, and old but relatively good amp, and i modified the tape monitor switches to be able to bypass the eq section. I was astonished by the fact that i couldn't hear any meaningful difference in between having this eq with the OLD original electrolitics inside the audio chain and without it...It has 10 electroltics , 50 years old in the audio chain! I managed to make Its amp work in class A as it had a 480w transformer and still couldn't hear a difference!
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It depends what the population data you have actually represents.
Say you measure hearing ability of 300 people, they are a sample of 300 out of a population of 7.5 billion. What are the chances of randomly selecting 300 test subjects, and having them not be very statistically representative? The chances are extremely high they will not be very representative. (Not to mention the chances you will not correctly measure what you are trying to measure, you may actually be measuring more of something else like the false negative chances of ABX DBT.)
Getting back to the example above, even if you think you know the demographics of a smaller population pretty well so you can improve the odds of selecting a representative sample, they may vary wildly in terms of the parameter you want to measure. If the reasons for wild variation are genetic, you may find all kinds of patterns among them that may look very causal based on what you know about the population demographics, but which are in fact totally random due to reasons you don't know about and never suspected. You are likely to (incorrectly) infer your measurements results reliably correlate with the demographics you do know about.
Its for reasons like the above and other complications that make accurate research on humans so hard.
The whole subject of biostatistics and the concerns expressed by Ioannidis is at least another semester course after statistics 101.
I will stop here.
Or somebody clued him in advance about the eight legged monster inside. Otherwise, it would be interesting to find out how you (or the reviewer) figured out it's the op amp that affected the sound, without knowing there's one inside and without peeking. Finding out would be a true progress, but then of course I am not holding my breath.
BTW, I don't need your trust, keep it for those appreciating it.
Good idea, since you are again in a swamp... You are confused (as many others, some of them are playing dumb o purpose) by not specifying exactly the hypothesis to test. Do you want to find out if X is audible for the average human in a certain demographics (usually those that are planned to be targeted by an ad campaign)? Or do you want to figure out if there is anybody/how many on this planet that are able to hear X?
These are two vastly different hypothesis, triggering completely different test plans, sample selection, etc... It is not unusual to hear from pros with an agenda that it doesn't matter that N-1 subjects are confirming the null hypothesis (that is, pure guessing), as long as there is one subject that hit say 16 out of 20, this confirms X is audible. It confirms ****, and the right answer to such events is to get that guy and run more tests to figure out if he was a lucky guess or he is indeed an extraordinary exception (and figure out how come) - which, of course, never happens, to the convenience of the "audio professionals".
As a continuation of our previous discussion about the different appreciation of "sighted" listening results.
I mentioned it only because of the again different appreciation, as I'm sure that the statement was accepted without asking for measured numbers or for rigorous controlled listening tests (including "blinding") .
The original arguments followed the line that measurements must show differences above the established thresholds of hearing; if that perequisite was dropped, the question arises what are we debating now wrt audible differences or the impossibility of audible differences?
It is enough to consider how, in the course of our own life, our sense of taste, our sight and our hearing has changed to conclude, with a minimum of logic, that it is simply stupid to generalize our own perceptions and to deny the possibility of differences between us.
The perception of the world around us passes through our senses and our culture. Our intellectual functioning is as varied as our perceptions, and wanting to impose our points of view on others is simply proof of a very limited intelligence (to remain polite).
We will have (almost) all noted also that perfection is not of this world, and that no natural or manufactured object is exactly the clone of another.
The perception of the world around us passes through our senses and our culture. Our intellectual functioning is as varied as our perceptions, and wanting to impose our points of view on others is simply proof of a very limited intelligence (to remain polite).
We will have (almost) all noted also that perfection is not of this world, and that no natural or manufactured object is exactly the clone of another.
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Ovi, it was always obvious it depends on the hypothesis. I don't have time to explain the obvious in every post that someone otherwise might misconstrue.
Congratulations on understanding the obvious, too bad you were too confused to avoid misconstruing once again. Maybe ask your wife or someone to read posts first so they can explain it to you.
Other than that, if you don't like hearing about known problems with medical research, complain to Ionaddis not me.
As far as I remember, I realized that it had to be the IC, because everything else in the circuit path was discrete. When I bypassed it, the sound got better.
When they told me that the amp had problems, they did not tell me that it was because of an IC at the input. I did talk to some later (different reviewer) many months later by phone and he asked ME why the MK2 version was better. I asserted that it was because I had removed the IC from the front end. I should have never said anything, but I did at the time. Perhaps it was some other changes in the amp that were just as important. I PRESUMED it was the IC, since that was the first thing that came to me and the only thing that I personally had changed between the MK1 and the MK2.
When they told me that the amp had problems, they did not tell me that it was because of an IC at the input. I did talk to some later (different reviewer) many months later by phone and he asked ME why the MK2 version was better. I asserted that it was because I had removed the IC from the front end. I should have never said anything, but I did at the time. Perhaps it was some other changes in the amp that were just as important. I PRESUMED it was the IC, since that was the first thing that came to me and the only thing that I personally had changed between the MK1 and the MK2.
Not sure anyone is still interested in the last discussion concerning the cymbal soundfile. To my surprise removing the content > 22.05kHz effects the amplitude envelope more than I thought. By amplitude envelope I meant the magnitude of the analytic signal from the Hilbert transform. When you simply mix (add) two sines the envelope is perceptible, I don't know why the conversation got so derailed.
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