Lumba Ogir said:
Lumba,
I did read most of it but found nothing. Only plenty with missunderstandings and lack of connection to facts and the real world.
I guess you have made up your mind and want to continue beliveing what you do. If you perform some proper blind tests you will learn a whole lot of new things though. Unless you are willing to walk the walk I see no use in discussing this further.
There is nothing whatsoever to back up anything of what you say. I had my gut feeling that this whas the case when you never really adressed my points but instead started to talk about apes and worms and stuff.
Hope you don't take it to personally, I'm just straight and honest. 🙂
/Peter
Pan said:
Peter, that is one of the most cogent and coherent posts I've read in a while. It's obviously informed by heavy experience. If I were to quibble, it would be comparing anything to a Rode (never met one I liked) and discounting transformers. Some I've measured have astonishingly low distortion, two leading zeros stuff at 1 volt. At mic level it would be unmeasurable.
Sorry I know this has gone off topic but I have to say one more thing. There are good mics that dont have proximity(and are still directional), but most peoople who record vocals dont use them becuase they want to add some color (low end). And most people do EQ and compress Vocals (and alot of the other instruments) (even classical music) if not while recording then while mixing. (how much have you actualy worked in a recording studio and who taught you?) The recording/mixing procces "is" manipulating, shaping the sound, starting with the mic. You said the mic is the weakest link, and I agree if your doing acoustical testing. If your recording music its your best tool.(one example:useing a mic thats not flat to EQ an instrument without the phase errors introduced by electronic EQ. For the kind of recordings you seem to like use a dummy head mic (this will get you as close to the original as possible) Most people hate the sound of these.
Originally posted by mfc
--------------------------------------------------------------------------------
I think it was Hiraga who first proposed the most "natural"
distortion pattern is one of decreasing level with increasing
order. The delta between one harmonic and its
immediate predecessor had to be somewhere between
10-25db.
As I recall the reason for this pattern was that the brain had to
make the same adjustment for naturally occurring ear
non-linearities.
Any device (amplifier) that could emulate this pattern would be
perceived by a listener as sounding "neutral" because the
ear/brain could not distinguish this pattern from its own internal processing.
Similiar to how the eye has a blind spot that is filled in and we don't even perceive it.
So their may actually be two ways to make a natural sounding
system. 1) Emulate this pattern, or 2) Eliminate distortion all
together.
Tube amps seem to have success because they try and do 1).
The hard part about 1) is that the delta between a harmonic
and its immediate predecessor may depend on level and
harmonic order.
--------------------------------------------------------------------------------
mfc
thanks for your post 🙂
Hiraga maybe, you say, suggested we would try to get a succesively decreasing of dist by order.
Would be interesting to see if he wrote about this.
=============================================
Maybe the main thinking of my topic could be changed to:
Just going for minimum THD % is no guarantee for best amplifier.
Because two identical 0.1 % THD values
can be very different in the individual harmonics content.
=============================================
Like I show in my IRF610 bias FFT diagram,
where the IRF610 is a buffer within feedback loop.
THD will not tell the magnitude of 3rd, 4th, 5th etc.
------------------------------------------------------------------------------------
It is like when you will go buy green apples and apples are in bags.
There can be any number of red, yellow or green in those bags.
On each bag is told the number of apples 10, 30 apples, 60 apples.
So which one would you buy in order to get most green apples 😀 😀
There might be 10 green apples in the 10-bag but only 1 green apple in the 60-bag.
The THD % is one total quantity. Tells not about specific harmonics & details, qualities.
But what kind of low distortion?
This is where our opinions are bit different.
Lineup
--------------------------------------------------------------------------------
I think it was Hiraga who first proposed the most "natural"
distortion pattern is one of decreasing level with increasing
order. The delta between one harmonic and its
immediate predecessor had to be somewhere between
10-25db.
As I recall the reason for this pattern was that the brain had to
make the same adjustment for naturally occurring ear
non-linearities.
Any device (amplifier) that could emulate this pattern would be
perceived by a listener as sounding "neutral" because the
ear/brain could not distinguish this pattern from its own internal processing.
Similiar to how the eye has a blind spot that is filled in and we don't even perceive it.
So their may actually be two ways to make a natural sounding
system. 1) Emulate this pattern, or 2) Eliminate distortion all
together.
Tube amps seem to have success because they try and do 1).
The hard part about 1) is that the delta between a harmonic
and its immediate predecessor may depend on level and
harmonic order.
--------------------------------------------------------------------------------
mfc
thanks for your post 🙂
Hiraga maybe, you say, suggested we would try to get a succesively decreasing of dist by order.
Would be interesting to see if he wrote about this.
=============================================
Maybe the main thinking of my topic could be changed to:
Just going for minimum THD % is no guarantee for best amplifier.
Because two identical 0.1 % THD values
can be very different in the individual harmonics content.
=============================================
Like I show in my IRF610 bias FFT diagram,
where the IRF610 is a buffer within feedback loop.
THD will not tell the magnitude of 3rd, 4th, 5th etc.
------------------------------------------------------------------------------------
It is like when you will go buy green apples and apples are in bags.
There can be any number of red, yellow or green in those bags.
On each bag is told the number of apples 10, 30 apples, 60 apples.
So which one would you buy in order to get most green apples 😀 😀
There might be 10 green apples in the 10-bag but only 1 green apple in the 60-bag.
The THD % is one total quantity. Tells not about specific harmonics & details, qualities.
There is no question about we all want low distortikon.
But what kind of low distortion?
This is where our opinions are bit different.
Lineup
Attachments
To Pan and Lumbe
How can the main process of distortion in the ear be compression since compression of a sound if it's mostly symetrical leads to 3rd harmonic and the main harmonic in the ear is 2th? Something is not right in here! Typically a membrane would have a symetrical distortion pattern and it would be mostly 3rd harmonic too.
Amazingly enough the main harmonic is the 2nd, the one being preponderant in a pipe type harmonic generation like the cochlea.
Amazingly enough the harmonic pattern the ear finds natural is looking like the one of a resonant closed pipe. But maybe that's not enough for you...
So I think the cochlea is dominant in the distortion process. I don't know why it is so hard to accept for you guy. Moreover several theries about the physiology of the ear present it as a resonator and a resonator produces harmonics, that's life.
I won't argue anymore, I guess it's no use.
How can the main process of distortion in the ear be compression since compression of a sound if it's mostly symetrical leads to 3rd harmonic and the main harmonic in the ear is 2th? Something is not right in here! Typically a membrane would have a symetrical distortion pattern and it would be mostly 3rd harmonic too.
Amazingly enough the main harmonic is the 2nd, the one being preponderant in a pipe type harmonic generation like the cochlea.
Amazingly enough the harmonic pattern the ear finds natural is looking like the one of a resonant closed pipe. But maybe that's not enough for you...
So I think the cochlea is dominant in the distortion process. I don't know why it is so hard to accept for you guy. Moreover several theries about the physiology of the ear present it as a resonator and a resonator produces harmonics, that's life.
I won't argue anymore, I guess it's no use.
lineup said:
It seems to me that it's not obvious at all. Many people want their coloration as we can see in this thread.
You ask what kind of distortion.. My answer (as an outspoken american may have phrased it 🙂 = I don't give a rat's a__ what kinds of distortion products I see popping up above the noise floor 140dB down as long it's not audible. And when we are talking 110-120dB down, I don't hear any distortion as I can judge from the tests I've done.
I think that some margin is wise though since even if one link (such as a global feedback amp *cough cough*) is shwon to be audible errorsa ccumulate in the chain and what I want is transparency from mic preamp to power amp.
The electroacoustical transducers I want as low distortion and low noise as possible. The polar patterns of mic's and speakers is always an art to some degree and IMO there's room for subjectivity there.
🙂
/Peter
rdf said:
Thanks!
Well the Röde and QT1's where at hand and what we tried. I guess there are better LDC mic's around even though this was their top of the line. More than that I hear lots of different anecdotes such as the MKH8040 vs. C12.
I also did some other tests and performance often is better with smaller capsules (if we disregard noise).
I guess I have to back on the transformer thing a bit. The distortion is there but as you say it may be low enough not to be audible if it's a good one. Reports pointing to TL mic's having a slight advantage though. I have not measured any trafos or trafo mic's and have not done any kinds of controlled listening tests either.
My remaining questions is, did you measure the trafo at high and low frequencies as well or at the typicall 1kHz? And then we have the bandwith which of course could be EQ'd if shown to be problematic in a given situation.
/Peter
cbdb said:
No. All directional mic's (pressure gradient) have proximity effect affecting the low end. Pressure mic's (omins) are free from it though.
Yes, and many don't. 🙂 I don't know where we are heading with this discussion but correcting EQ is not something I see as distortion but more like "distortion removal".
It's a matter of philosophy and it depends on what you want to do. I'm all for supercool subjectively pleasing but very non realistic music as much as I love purist recordings with the aim of capturing and playback a musical event as unaltered as possible.
Actually the opposite. There's "always" ways to adapt and use measurement mic's to study acoustics by optimizing the relevant parameters. Music is another story and in particular noise is a big problem.
I would pay 5000-10000$ for a pair of small omnis (QTC1, QTC50) with 5dBA selfnoise.
Well, I can't really argue with that. No mic = no music! ;-)
And that's a very common missunderstanding. Mic's, speakers (exception the crossover in some speakers) and analog electronics (and even room resonances) are basically minimum phase devices. This means that phase follow frequency response.
If you have a mic that has non flat response it will have phase distortion. All mic's and speakers has a roll off at both ends of the spectrum meaning they are bandpass devices and this always means phase distortion. Now, if you have a bump in the middle of a mic's range (or a lift up high) and correct the frequency response with EQ you will restore the frequency resposne AND phase response. Beatiful eh? 🙂
No for heavens sake!! Dummy head recordings are intended for headphone listening (which I enjoy as well of course). The head encodes the HRTF into both channels compensating for the fact that headphones fire straight into the ears and side steping this natural process.
With stereophony you don't want to encode HRTF into the record since that would mean the signal has been encoded two times before it reach the brain. That does not work out very well.
Sterephony is not about capturing a sound at the mic's as the ears would have done in the recording hall/venue. It's about capturing a wavefront and pack that up with the help of the speakers on the other side of the chain.
And writing this I begin to wonder if you actually meant that I should stick to headphones if I want accuracy and life like reproduction?
I'll answer that, headphone listening is nice and really cool with binaural recordings but IMO it does not come close to the realism of good stereophony.
/Peter
darian said:
First, I never said i have a grip on this. Second a symetrical membrane with equal loads on both sides will have symmetrical distortion (odd order). The eardrum.. is it symmetricall? Does it see equal impedances on both sides? What abou the mechanicall attachments to the small bones in the middle ear?
I don't know, just speculating and asking.
No, that's certainly not "enough for me"! 🙂
You think? You seemed so sure just a second ago.
Now you're loosing me. Do you mean that your speculations (partly erroneous) is something that we should take as fact and scientificall evidence??
Loosen up man, this is a discussion board. 🙂
/Peter
So many theories. Why make it hard, when it's all very simple. Just compare the amp to nothing. The less you can "hear it", added to a system, the better.
Pan said:
Always. Varies wildly by transformer, and frequency response aberrations remain of course. The best in my stock is tiny OEM output pulled from a SS tape machine, distortion performance rivaling the ability of an M-Audio running 24-bit to measure. Going from memory, it rose at the low end but didn't exceed 0.01% at 1 volt.
Pan said:
Pan 😀
I can't argue with that one.
As long as I can not hear dist
I do not care whatever kind of distortion it is there ..
Very good 🙂
To Pan,
Well, for sure the ear drum is not equaly loaded on both sides but the movements are really little so unless very high sound levels it shouldn't go into serious "clipping". As Lumba said "The ear drum turns sound waves into vibrations quite linearly over sound pressures of 40 to 110 dB SPL" and that's what I read in some medical article too a long time ago.
By the way, if one of you has an article explaining that the main source of distortion is not the cochlea, feel free to post.
The problem here is that I bring some well proven arguments when I talk, some being theories more than a century old and still trusted (like the cochlea being seen as a resonant sytem and obviously creating harmonics in a fair amount).
But when you dismiss my theory, you only say "That's how it is".
This is not easy to have a constructive discussion in these conditions. Maybe you could post an article yourself or a reference.
And when I say "I think", it's to be less definitive and less agressive in my writing. Why do you say I am "erroneous" without bringing any other explaination? As you may know, there is a technic in physiological exploration of the ear using bone conduction and shortcuting the eardrum and beside the obvious attenuation of the low frequencies, as far as I know there is no sudden "clarity" feeling even if we shorcut all these nasty membrane and ear bones...
Regards
Well, for sure the ear drum is not equaly loaded on both sides but the movements are really little so unless very high sound levels it shouldn't go into serious "clipping". As Lumba said "The ear drum turns sound waves into vibrations quite linearly over sound pressures of 40 to 110 dB SPL" and that's what I read in some medical article too a long time ago.
By the way, if one of you has an article explaining that the main source of distortion is not the cochlea, feel free to post.
The problem here is that I bring some well proven arguments when I talk, some being theories more than a century old and still trusted (like the cochlea being seen as a resonant sytem and obviously creating harmonics in a fair amount).
But when you dismiss my theory, you only say "That's how it is".
This is not easy to have a constructive discussion in these conditions. Maybe you could post an article yourself or a reference.
And when I say "I think", it's to be less definitive and less agressive in my writing. Why do you say I am "erroneous" without bringing any other explaination? As you may know, there is a technic in physiological exploration of the ear using bone conduction and shortcuting the eardrum and beside the obvious attenuation of the low frequencies, as far as I know there is no sudden "clarity" feeling even if we shorcut all these nasty membrane and ear bones...
Regards
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