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[Nika Aldrich]

Johnny B wrote on Thu, 24 June 2004 23:02

Nika, We are not lkimited here to looking at only the highs, but rather, we can look at the entire freq. spectrum. Now that you mention the ear, how does your understanding of the ear's biology explain our ability to sense extreme low freq. content? Say around 8.5Hz?

It doesn't happen in the ear at all.  The lowest frequency that the basilar membrane can resonate at is right in the area of 20Hz.  If it can't resonate any lower than that then it can't convey neurological synapses to the brain.  If it can't do that then we can't hear it.  

We FEEL 8Hz as was explained above.

Nika.

[RobertRandolph]

Nika Aldrich wrote on Thu, 24 June 2004 23:47

Johnny B wrote on Thu, 24 June 2004 23:02 Nika, We are not lkimited here to looking at only the highs, but rather, we can look at the entire freq. spectrum. Now that you mention the ear, how does your understanding of the ear's biology explain our ability to sense extreme low freq. content? Say around 8.5Hz?   It doesn't happen in the ear at all.  The lowest frequency that the basilar membrane can resonate at is right in the area of 20Hz.  If it can't resonate any lower than that then it can't convey neurological synapses to the brain.  If it can't do that then we can't hear it.   We FEEL 8Hz as was explained above. Nika.

Actually there is research that indicates a 10hz sine wave can cause the ear to vibrate at near perfect harmonic intervals. Thus causing us to "hear" the sound. We certainly in no way are hearing 10hz. We are hearing 20hz and more harmonics, at the very least.. and it still needs to be VERY loud, to the point where when you hear it... you're about to go deaf anyways.

And of course, the inability of most tranducers to cleanly reproduce these frequencies leads to many harmonics, in the audible range, to be heard by our ears. Even when the medium does pick it up, we are not hearing it. Though it can have effect on the recording... it is certainly a negative effect for reason listed above.

[Johnny B]

Robert,

You raised an good point.  

I've been told that in the 30's, 40's, 50's or 6o's, (forgot which) they supposedly made a 24- or 28-inch bass speaker which I was also told was extremely efficient. They said it worked at low watts and did not require huge volume. I do not remember what I was told about its freq. response range.

I've also been told that many of today's bass speaker drivers require lots of power to move extremely stiff cone material made from kevlar and whatnot. I'd imagine that particular application would work well in the sound reinforcement field, say, at an outdoor shed venue where massive volume may be desired.

But Robert, do you think it is just possible to design a super efficient bass driver that goes down to 8.5Hz and does not require huge watts or SPLs? Just possible?

[RobertRandolph]

Johnny B wrote on Fri, 25 June 2004 00:01

But Robert, do you think it is just possible to design a super efficient bass driver that goes down to 8.5Hz and does not require huge watts or SPLs? Just possible?

Im talking about the physical air that needs to be moved for the human to experienced. Sure you can move enough air... but this is what SPL is. When you move so much air, even if it isnt "loud"... the spl will still be extreme. You can have SPL's well into 200db, with no audible sound at all... many high-tech refridgeration units and compressors acheive this.

wattage is an entirely different matter... related to the tranducer, not the human experience directly. Im pretty sure we're talking about the human experience, until the inssue of "recording" it came into play.

[Johnny B]

Robert,

Ok, I'm just trying to say the old 24- or 28-inch speakers
did move more air because they were bigger and made from lighter materials making them more efficient to some degree. My second point being, with better designed bass drivers, perhaps we can get around the problems you raised. Should we not do this if we want to give people a more true-to-life experience?

I also found your point on the harmonic interaction of the lows to be very interesting indeed.


 

[RobertRandolph]

Johnny B wrote on Fri, 25 June 2004 00:15

Robert, Ok, I'm just trying to say the old 24- or 28-inch speakers did move more air because they were bigger and made from lighter materials making them more efficient to some degree. My second point being, with better designed bass drivers, perhaps we can get around the problems you raised. Should we not do this if we want to give people a more true-to-life experience? I also found your point on the harmonic interaction of the lows to be very interesting indeed.

I do not think you understand SPL and volume are not related in this context. In order to create sub 20hz waves, that can be felt by a normal individual, it MUST have a high SPL. There is no getting around it. Better designed drivers wont matter. The transducer will always exhibit some audible harmonics due to various physical forces. A theoretically perfect transducer, reproducing a complex signal will even have some harmonic content not present in the original.

[Eliott James]

Let's approach it this way. You have the time. You have the funding. You are  commited to maintaining an open mind, and you are excitied because you are given a clean sheet of paper to develop a recording and playback system that will reproduce the source recorded, just as if you were in the room with the musicians.

We all know what we have now does not do this. When we playback the recording we are not hearing the string quartet that was playing in front of us in the studio.

So why?

How do we make mics better, converters better, recording medium better, DAs better, amps better, and speakers better?

We've got various opinions on the math and science, but who can put this goal into realization? Why do we accept boundries?

Forget about making money. It's about re-creating the source material.

How do we do it?

[RobertRandolph]

EJ wrote on Fri, 25 June 2004 00:22

We've got various opinions on the math and science, but who can put this goal into realization? Why do we accept boundries? Forget about making money. It's about re-creating the source material. How do we do it?

We accept boundaries because our physical bodies have boundaries. As much as humans like to think we are not, we are VERY limited creatures. Certainly we are more advanced than our creations (computers), but we are indeed limited.

Thus, it is in the interest of progression to limit reproduction to the limits of our senses. Otherwise, progress would never be made. We'd spend 100's of years making faster sampling rates rather than making better guitar strings.

As for the comment on math and science... If it is an opinion on math, then it is not math.

[Johnny B]

Robert.

I know it only takes one good shock to damage your ears,
I think I learned that from H.E.A.R.

But are you saying that the ONLY way to reproduce those low,
lows is by risking your health?

If so, do you have a health study
or article or something else you know which underpins this?



 

[RobertRandolph]

Johnny B wrote on Fri, 25 June 2004 00:31

Robert. I know it only takes one good shock to damage your ears, I think I learned that from H.E.A.R. But are you saying that the ONLY way to reproduce those low, lows is by risking your health? If so, do you have a health study or article or something else you know which underpins this?

Thus bringing us to the first post. If you can find a good research article showing we can feel 8hz (or hear) at low SPL's, then I will be obligated to prove this wrong. Until then, this is physical fact and common sense.

You can reproduce those lows at a resonable level. But you cannot experience them at a reasonable leve, therefore trying to reproduce them at a reasonable level is completel futile and a waste of time and effort.

[djui5]

here we go....

For starters...I've always though it was (or seems to be) hard for people to differentate between heard sound and felt sounds...

Sure..you can feel 10hz....the speaker moves air and causes vibrations that your bodys nerves picks up and  translates to the brain...ahhh  massages...
Sure..you can hear 20hz...but can you really hear anything below that?...I believe not. I believe anyone who says you can is confusing feeling with hearing.
Can you feel freq's about 20Khz...sure....can you hear them..I'd say no...anyone who disagrees is feeling them..not hearing them.
You can talk harmonics and math crap all you want....but do a hearing test.. I'll bet you can't hear past 20K...hell..most AE's can't hear past 17K....

I also think it would be best to differentate between freq ranges of equipment and hearing. If we're talking about freq response of gear...keep it that way and don't involve your hearing or feeling into the equation.

Me...

I'm sticking to 20-20K

As for gear...that's a different story and I have no idea how high that goes...never tested it. We also run into another problem when testing freq response of gear as theres limitations on the test equipment also..after all..it's just a piece of gear too.

[djui5]

RobertRandolph wrote on Thu, 24 June 2004 17:38

Thus bringing us to the first post. If you can find a good research article showing we can feel 8hz (or hear) at low SPL's,

I've ran subs to 5hz....and felt it....

[Eliott James]

We accept boundaries because our physical bodies have boundaries. As much as humans like to think we are not, we are VERY limited creatures. Certainly we are more advanced than our creations (computers), but we are indeed limited.



What boundries are in place in that we naturally hear a full sound of the string quartet in the studio? With no damage to our ears or body.

Can we reproduce that sound that we hear naturally? That's all I'm talking about. A faithfull and true re-creation of what we naturally hear. It will require refinements in the entire signal chain. So how do we do it?

[Paul Frindle]

Johnny B wrote on Thu, 24 June 2004 22:07

In the past it was commonly accepted that human beings could only hear from 20Hz to 20Khz. Some people have challenged this old belief. So here, feel free to post links or things you know about the ear.

You know, this thread 'could' be great idea. And this subject I could go on forever about, to everyone's complete boredom.
But - it will inevitably digress into a discussion of sample rates, data lengths and 'resolution' for the n'th time.

More this, more that, more anything and everything - never WHY or HOW

From the bottom of my heart and after decades of experience, listening, arguing and striving on this subject at every level, the most crushingly disappointing thing of all for me is the degree to which we and the establishment persistantly and relentlessly UNDERESTIMATE what we CAN hear - whilst striving to provide ever increasing amounts of what we CANNOT hear

IMLE most everyone on both sides of the argument consistently underestimates the astounding subtlety and power of what the ear/brain mechanism achieves every second of our waking lives from birth to death, whilst just going about our daily lives without a second thought.

Also IMLE almost no one, whether academic or user, will believe it when you make these suggestions. Often they won't accept it even when demonstrated in the cold light of day.
Prefering instead to search amongst ever-deeper minutae of 'accepted' technical analysis for ever-increasingly esoteric and academically 'blessed' explanations relating to the ever-present and immoveable underestimation - represented by the "universally accepted limitations in our hearing mechanism and perception processes".

This definitely isn't a thread I should follow if I want to get to bed at night

[RobertRandolph]

EJ wrote on Fri, 25 June 2004 02:08

We accept boundaries because our physical bodies have boundaries. As much as humans like to think we are not, we are VERY limited creatures. Certainly we are more advanced than our creations (computers), but we are indeed limited. What boundries are in place in that we naturally hear a full sound of the string quartet in the studio? With no damage to our ears or body. Can we reproduce that sound that we hear naturally? That's all I'm talking about. A faithfull and true re-creation of what we naturally hear. It will require refinements in the entire signal chain. So how do we do it?

This has nothing to do with sub or supersonic frequencies though. The boundaries are there to overcome, but the certainly are not a bandwidth issue.

Of course, a string quartet has true depth as well. 4 sounds coming from 4 specific positions. If we could create transducers which eminate sound in the manner identical or discernably similiar to that of the original instrumnet, then placed these transducers in the same spots. Then simulated the physical moving of the sound producing body (the transducer in this case)... perhaps we'll get close.

For now, the biggest limitation is you're listening to a 4 dimensional sound through a 1 dimensional medium, the only dimension being time in the reproduced material. There is no X, there is no Y and there is no Z. They are only simulated by the 2 speakers by use of a mechanical vibration occuring over TIME. In a natural performance, all 4 dimensions exist and are not simulated.