I'm wasting DIY? Nobody can dut? Apparently, not only is your keyboard defective, with the Caps Lock stuck on (wasting quite a bit of surface area), but so is your grammatical ability.
An externally hosted image should be here but it was not working when we last tested it.
abzug- just curious, why should I care about THD for signals above 7.5kHz, half the limit of my hearing?
I can hear to 19, but that's beyond the point. The argument that THD20k should be used I initially saw by Bob Cordell in one kof the various sticky threads in his name here. Since THD usually rises with frequency, it's best revealed at a test near the upper range of what frequency is to be reproduced. If you really can only hear to 15 kHz, then sure, measure at that frequency.
I'll remind people of the Japanese study that showed there were definite effects of > 20 kHz sound on mental state:
T. Oohashi, E. Nishina, M. Honda, Y. Yonekura, Y. Fuwamoto, N. Kawai, T. Maekawa, S. Nakamura, H. Fukuyama, and H. Shibasaki. Inaudible high-frequency sounds affect brain activity: Hypersonic effect. Journal of Neurophysiology, 83(6):3548–3558, 2000.
Also, http://en.wikipedia.org/wiki/Ultrasonic_hearing
Note the 120 kHz (!) number quoted.
I'll remind people of the Japanese study that showed there were definite effects of > 20 kHz sound on mental state:
T. Oohashi, E. Nishina, M. Honda, Y. Yonekura, Y. Fuwamoto, N. Kawai, T. Maekawa, S. Nakamura, H. Fukuyama, and H. Shibasaki. Inaudible high-frequency sounds affect brain activity: Hypersonic effect. Journal of Neurophysiology, 83(6):3548–3558, 2000.
Also, http://en.wikipedia.org/wiki/Ultrasonic_hearing
Note the 120 kHz (!) number quoted.
http://www.gedlee.com/distortion_perception.htm
If you build your own loudspeakers, his Audio, Acoustics and Perception is a must read also. Unless of course, you reject the notion that measurements are useful/applicable for sound waves too 😉.
cheers,
AJ
If you build your own loudspeakers, his Audio, Acoustics and Perception is a must read also. Unless of course, you reject the notion that measurements are useful/applicable for sound waves too 😉.
cheers,
AJ
bear said:
http://www.gedlee.com/downloads/THD_.pdf
It was a little hard to find (from the main page, click 'sound quality', then click 'this paper is available here').
I read the link, and although somewhat impressive, I wouldn't call it definitive at all. This is one couple's hypothesis, and really needs way more evidence to be deemed useful. I was disappointed by the lack of hard evidence/documentation/explanation on Earl's website. The above link is just a magazine article someone wrote on Earl's ideas, and seems to be the bulk of what he has to offer on the subject, which is unfortunate, because he has obviously put a lot into it...
The bottom line here is that we know so little about how humans perceive the sound quality
of an audio system, and in particular the loudspeaker, that one should question almost everything
that we think we know about measuring it. From what we have found most of what is being done
in this regard is naive.
Earl geddes
hm WHAT DID MY EX HAG SAY ABOUT HOW HUMANS HEAR??
That what we percieve (our brain has processed) is what we actually hear and no scientific study can tell us otherwise!!
we still have no real clue how the AD converision takes place in humans only theories that are getting close approximations
BTW she pissed off alot of psycho babble types in her doctoral thesis!!
of an audio system, and in particular the loudspeaker, that one should question almost everything
that we think we know about measuring it. From what we have found most of what is being done
in this regard is naive.
Earl geddes
hm WHAT DID MY EX HAG SAY ABOUT HOW HUMANS HEAR??
That what we percieve (our brain has processed) is what we actually hear and no scientific study can tell us otherwise!!
we still have no real clue how the AD converision takes place in humans only theories that are getting close approximations
BTW she pissed off alot of psycho babble types in her doctoral thesis!!
IMSTOOPID said:
Put the whiskey down, Captain Cruise Control... we're not interested in drunken raging stories about exes.
I thought we were talking about amps?
That is false. What you perceive is not just what you hear, but also your psychological biases. Only a carefully controlled blind test can eliminate those, not the average amateur's experiment.
They're close approximations, and getting closer yet, in terms of both otophysiology and neurology. The room left for audiophile BS is becoming ever more narrow. The fact is there is a pretty good idea how conversion happens (and calling it AD makes no sense, because rate coding is not digital--the timing of neuron firing is still an analog quantity).
When I was younger I had an old color 25" console TV. I used to hear it make a real high tone that most could not hear, I hated it. I think it was the tube doing it, or associated hardware. It was very irritating. Sometimes I had to move around the room until I could not hear it, and some days it did not make the tone. IIRC it did it when shut off as well as the tube died out.
. Only a carefully controlled blind test can eliminate those, not the average amateur's experiment.
TELL MY EX THAT..SHE GOT HE DOCTORAL THESIS ON THIS..
bTW BLIND TEST INDUCE STRESS,. stress makes errors..
there is no way to do a blind test (if the subject knows they are being tested) and get accurate resutls!!!
that was part of her thesis..ask the DR. herself..
I could be an azzzzzzzzzz and pos her Phone #>>LMAO
hey're close approximations, and getting closer yet, in terms of both otophysiology and neurology. The room left for audiophile BS is becoming ever more narrow. The fact is there is a pretty good idea how conversion happens (and calling it AD makes no sense, because rate coding is not digital--the timing of neuron firing is still an analog quantity
that;'s only one theory.. and they are still arguing about that.!!..
got to check with the los almos guys
TELL MY EX THAT..SHE GOT HE DOCTORAL THESIS ON THIS..
bTW BLIND TEST INDUCE STRESS,. stress makes errors..
there is no way to do a blind test (if the subject knows they are being tested) and get accurate resutls!!!
that was part of her thesis..ask the DR. herself..
I could be an azzzzzzzzzz and pos her Phone #>>LMAO
hey're close approximations, and getting closer yet, in terms of both otophysiology and neurology. The room left for audiophile BS is becoming ever more narrow. The fact is there is a pretty good idea how conversion happens (and calling it AD makes no sense, because rate coding is not digital--the timing of neuron firing is still an analog quantity
that;'s only one theory.. and they are still arguing about that.!!..
got to check with the los almos guys
Many CRT TVs have that high pitched hum. I think it's the horizontal scan rate at 15.75 kHz for NTSC--not that high and most people would hear it, except the old ones.
If she's Asian by any chance, hook me up. I'm about done with white women 😀IMSTOOPID said:
I jest
Subjective - definition 1: The ability to convince yourself things are different when in fact they are the same.
Subjective - definition 2: The ability to convince yourself things are the same when in fact they are different.
Why does one definition take precedence over the other? i.e. The posts I've read by the believers that all properly made amplifiers sound the same, automatically assume that their judgment is not subjective. They feel that those people who claim to hear a difference have a judgment that is both subjective and suspect.
Many tests have been made about the threshold of audible detection, according to all of these I've ever read no one could tell a difference between Redbook CD and SACD. Can you?
The subject, the tests, the criteria are complex enough that it's is quite unlikely it could be dealt with in a forum where the average post runs 50 words or so and is composed in a few seconds on the fly while responding to another contributor.
Thousands of words about this issue are available on the internet. Many people have devoted real effort in an attempt at understanding this issue. If you read many of these papers you are left with a feeling that the sum total of all results are can best be summed up as "inconclusive".
Luckily for me I only have to make myself happy with my hobby. If you ask me what I think, I'll happily tell you. But I'm just as certainly going to continue doing what I'm already doing.
Subjective - definition 2: The ability to convince yourself things are the same when in fact they are different.
Why does one definition take precedence over the other? i.e. The posts I've read by the believers that all properly made amplifiers sound the same, automatically assume that their judgment is not subjective. They feel that those people who claim to hear a difference have a judgment that is both subjective and suspect.
Many tests have been made about the threshold of audible detection, according to all of these I've ever read no one could tell a difference between Redbook CD and SACD. Can you?
The subject, the tests, the criteria are complex enough that it's is quite unlikely it could be dealt with in a forum where the average post runs 50 words or so and is composed in a few seconds on the fly while responding to another contributor.
Thousands of words about this issue are available on the internet. Many people have devoted real effort in an attempt at understanding this issue. If you read many of these papers you are left with a feeling that the sum total of all results are can best be summed up as "inconclusive".
Luckily for me I only have to make myself happy with my hobby. If you ask me what I think, I'll happily tell you. But I'm just as certainly going to continue doing what I'm already doing.
That's a fascinating hypothesis. Are you saying that ALL perceptual studies in ALL fields are invalid because of this? Is that the claim of the much-glorified thesis?IMSTOOPID said:
I suspect, however, that you are a troll, and no such thesis exists.
That would be most interesting.planet10 said:
One of the problems with the ABX protocol is that it can only disprove (1), and not (2). Other test protocols are available which can get a start on addressing (2). This doesn't, however, make ABX useless - blind tests of this type are still one of the best tools we have for controlling for perceptual bias.hermanv said:
I wonder how many of the audio blind test deniers here would be happy if pharmaceutical companies stopped blind testing of drugs for safety and simply released them to the market when someone that took them said they felt better.
abzug said:
If there was a blind test for audio that was comparable in quality to the tests the pharmaceurtical companies use, then we might be talking.
dave
Re: Hi-fi is a dead subject.
Oh good. Someone else remembering that we are using the technology as a means and not an end. Thanks.
If you can't make the effort to do play an instrument, then try singing - one of the middle parts of a choir. Then you begin to listen to what happens within the harmony. Then the lower the distortion, and the better the frequency response of your amplifier, the more of the MUSIC you will hear.
Once you can hear the individuals (usually because they have cocked it up somehow: poor intonation; bad timing) then your system is getting somewhere.
Andy
Ps: Al, caps. intentional
wakibaki said:
Oh good. Someone else remembering that we are using the technology as a means and not an end. Thanks.
If you can't make the effort to do play an instrument, then try singing - one of the middle parts of a choir. Then you begin to listen to what happens within the harmony. Then the lower the distortion, and the better the frequency response of your amplifier, the more of the MUSIC you will hear.
Once you can hear the individuals (usually because they have cocked it up somehow: poor intonation; bad timing) then your system is getting somewhere.
Andy
Ps: Al, caps. intentional
Just a silly question:
IF all amps sound the same, then why DIY? Just for fun? To penny pinch? For the cool factor?
It's pretty easy these days to buy an amp with impeccable specs for not much money. If you need a powerhouse, get a pro amp, even used. It sounds the same as any other amp, right?
Why bother to build, and why so many different designs?
Not arguing that sonic differences exist because of all the different amp commercial types and DIY, but it does make you scratch your head.
IF all amps sound the same, then why DIY? Just for fun? To penny pinch? For the cool factor?
It's pretty easy these days to buy an amp with impeccable specs for not much money. If you need a powerhouse, get a pro amp, even used. It sounds the same as any other amp, right?
Why bother to build, and why so many different designs?
Not arguing that sonic differences exist because of all the different amp commercial types and DIY, but it does make you scratch your head.
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