Seems to me there is too much focus on the top end of FR when talking about hearing loss.
Losses down lower seem more important to me. A loss at 6K or 3K can make quite a difference, even if your hearing does extend to 16Khz.
Upper mid-range losses can be caused by noise or ear infections. They will affect you hearing ability much more than the "I can't hear 18Khz any more" losses.
Losses down lower seem more important to me. A loss at 6K or 3K can make quite a difference, even if your hearing does extend to 16Khz.
Upper mid-range losses can be caused by noise or ear infections. They will affect you hearing ability much more than the "I can't hear 18Khz any more" losses.
No such thing as the audibility threahold of THD. Like, no such threshold of healtahibility of average temperature of patients in a clinic. Like temperature of each patient means different things according to his/her diagnosis, audibility of distortions depend on many factors, like loudness, order, dynamic behavior.
Oh, I have ambitions of doing some "high-end" things I guess, but as well it would be nice to be able to recommend parts to people and have some confidence that I'm giving out reliable information. I spent years designing the electronics for cheap powered speakers that shipped in the millions, and enjoyed providing the best quality that could be accomodated by the cost target. Been there, done that, but unfortunately behaved in my expenditures as if it would go on forever*. Now things, almost impossibly, have gotten not so much cheaper but a good deal poorer, as essentially no one seems to mind
The tide may turn in time. At least the nonsense that youth prefer MP3 over higher-resolution audio, put forth on the basis of very poorly-controlled experiments by some professor, has been debunked by Sean Olive in better tests. So I think there is some hope.
Brad
*so my ambitions are thwarted if they are to make a small fortune, since I don't have a large one to start with.
Yes, due to a rule violating layout. They are way smaller than most equivalent parts. But remember now there are several parts with sub-nanoVolt noise due to the sub-micron geometries that are available.
Yes it's remarkable what is going on. I remember when Barrie G. told me about experimental devices at AD with complex structures that, among other things, were showing beta's of order 100k. A curiosity, although it makes finite beta less of a nuisance for translinear designs I suppose.
And in switchmode we have the advent of GaN, more things to grey the hairs of what Bruce H. has left
, with switching frequencies posited as in the offing of ~50MHz. I think the magnetics lag a bit, although I saw a little 20MHz power supply the other day.
This is a cute circuit for a modified WM61 or equivalent. The distortion will be from the capsule only.
Attachments
For those who care about speaker distortion, Soundstage, in their speaker reviews, provides data from the NRC on speaker distortion and specify the SPL. It is interesting that some highly touted speakers have relatively high levels of distortion. The spectrum of the distortion is also interesting. I assume it is THD only. Regards
Is the capsule cold side referenced to ground? Is there a gate resistor, and if so to what is it referenced?
When you say it is THD only, do you mean that they don't attempt to measure IM?
I like it. The loading effects of the FET capacitances are almost entirely bootstrapped out, both at source (which looks like it's being fed from about a megohm or so) and at drain, and with that their propensity to distort is removed. Output Z is fairly low, and who cares if you don't have voltage gain as you can supply that readily enough afterwards. Power consumption is low.
Sometimes capacitors are our friends.
Nice. The same trick like in my Tower class A output stages, where I used bootstrapped source follower loaded on modulated current source. 600W per channel of heat manufacturing.
Hi,
The Grado has a moderate lift around 2KHz (you might call that the "Anti-BBC Peak" and a 6dB peak around 10KHz. No wonder it punches holes into ones eardrums. I never brought a Grado, but we had a SR60 at the factory (together with others) to be able to go around the burn in racks and jack into each machines output, to check is everything was ok.
I hated the Grado.
Ciao T
The Grado has a moderate lift around 2KHz (you might call that the "Anti-BBC Peak" and a 6dB peak around 10KHz. No wonder it punches holes into ones eardrums. I never brought a Grado, but we had a SR60 at the factory (together with others) to be able to go around the burn in racks and jack into each machines output, to check is everything was ok.
I hated the Grado.
Ciao T
On ears and cotton buds:
Obviously, different schools of thought exist. Not the first time, and in medicine, the most common of all things. Like butter - in 1975, butter was death itself, in 1977, it was a cure-all, then again a killer, then ....
I don't use them on feeling only, I did ask my doctor to teach me on how to use them. I am not of the modern persuasion which has it that when everything else fails, read the manual, rather, I am an old timer who likes to ask and reads the manual beforehand.
On High End:
Brad, what do you call "High End"? Where does Mid Fi give way to High End? What determines the High End?
As far as I am aware, there is no universal definition, people mostly relate to price, when it goes up high enough then you're in the High End territory, but my experience teaches me that that for quite some time, higher price was not a guarantee of high quality, rather just a probability for it.
Obviously, different schools of thought exist. Not the first time, and in medicine, the most common of all things. Like butter - in 1975, butter was death itself, in 1977, it was a cure-all, then again a killer, then ....
I don't use them on feeling only, I did ask my doctor to teach me on how to use them. I am not of the modern persuasion which has it that when everything else fails, read the manual, rather, I am an old timer who likes to ask and reads the manual beforehand.
On High End:
Brad, what do you call "High End"? Where does Mid Fi give way to High End? What determines the High End?
As far as I am aware, there is no universal definition, people mostly relate to price, when it goes up high enough then you're in the High End territory, but my experience teaches me that that for quite some time, higher price was not a guarantee of high quality, rather just a probability for it.
They don't mix if you wanna keep your hearing sharp. I was told by a nurse who syringed my ears out many years ago that cotton buds shed minute amounts of fibre which tend to form (over time) solid plugs when mixed with ear wax.
<edit> Ah I now see SoNic has had what seems to be similar advice
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They don't mix if you wanna keep your hearing sharp. I was told by a nurse who syringed my ears out many years ago that cotton buds shed minute amounts of fibre which tend to form (over time) solid plugs when mixed with ear wax.
<edit> Ah I now see SoNic has had what seems to be similar advice
With all respect, I very much doubt such an explanation. This would make cotton buds extremely dangerous to babies, and I just don't see governments letting something like that happen.
Of course, if one uses cotton buds, one does not need to visit the doctor as often, which does reduce the doctor's income for an easy, no risk service, perhaps that may be relevant to an extent ...
You know, whenever I hear an explanation which just doesn't make sense, or when I'm baffled by an event, I always ask myself the magical question which provides an answer when all else fails - which way does the money flow? And suddenly, lo and behold!, everything becomes much clearer.
You have a lot more faith in government than I. I'm old enough to remember a drug called 'Thalidomide' which was used in UK
But in UK the service was, at that time, 'free at the point of delivery'. So whilst I agree wholeheartedly with the notion of 'follow the money trail', it fails quite miserably here. I'd rather bet the nurse didn't really want to syringe so many people's ears so was altruistic in giving advice.
Yes, there's that too.
Not that I can complain; I needed medical service while in the UK just once, in summer of '69, when I was riding a bike down a slope in Somerset at around 30 mph, only to discover that the foldable bike had become two half bikes because the connector broke off. I lived, jumping onto the grass lawn by the roadside, narrowly missing an Austin I would have collided with, and suffered only a minor cut on the arm. Jack, the local Over Stowey cop (pop. about 200), actually gave me a ride on his official motorcycle to the local doctor, who patched me up so well that there is no trace of it even using a magnifying glass. Outstanding!
In those days, local authorities had an impressive performance record, with no loose ends. And people ask me why I remember my years in the UK so fondly.
When I wanted to pay, I was told that even if I was a stranger in a strange land, I did have medical insurance paid for as a part of my school tuition fees and I had nothing to pay for.
My sticker says "Made in 1953", what's yours?
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