Hi MJL21193, gedlee,
Now, for the members who want to pick at each other ....
Cal has warned about this twice now. Let's see some professional behavior from people who should know better. If you want to discuss an idea, fine. If you want to squabble in these forums, you will see some action from the moderating team. Remain factual and cut people some slack.
I am not in the mood for continued attacks.
-Chris
That might be a good idea. If nothing else, the arguments have no reason to follow ......
You know what? That is what bothers me, and I'm sure many other members. Please begin somewhere where you can hear yourself think. You have our support.
Now, for the members who want to pick at each other ....
Cal has warned about this twice now. Let's see some professional behavior from people who should know better. If you want to discuss an idea, fine. If you want to squabble in these forums, you will see some action from the moderating team. Remain factual and cut people some slack.
I am not in the mood for continued attacks.
-Chris
In reality, everything is compressible to some extent.gedlee said:
After some study on horns/guides, I am getting some feeling how nulls might be forming, but it's still unclear whether it has anything to do with so called HOMs or not. Normally if HOMs in frequencies lower than 10KHz exists, we would be able to see them in the CSD charts. I cannot comment on how it might look until I have some guides/horns for testing.gedlee said:
Yes, everything is compressible to some extent.
And, I do believe that HOMs should be vissible in the CSD, but I have not had the time to delve into this in much detail. You will notice in the writups that I directed you to that the use of the foam plug is most evident on the tails of the impulse response clearly indicating that a damping of the later ringing or difffraction effects is apparent.
I'd like to say here that it is not my intention to supress anyones beliefs or ideas, but since this thread carries my name I do feel responsible to correct errors and inaccuracies when they are presented. The correction of an incorrect statement is not a suppression of ideas. I generally do not correct mistatements in other posts, but I do correct them in ones that I host.
And, I do believe that HOMs should be vissible in the CSD, but I have not had the time to delve into this in much detail. You will notice in the writups that I directed you to that the use of the foam plug is most evident on the tails of the impulse response clearly indicating that a damping of the later ringing or difffraction effects is apparent.
I'd like to say here that it is not my intention to supress anyones beliefs or ideas, but since this thread carries my name I do feel responsible to correct errors and inaccuracies when they are presented. The correction of an incorrect statement is not a suppression of ideas. I generally do not correct mistatements in other posts, but I do correct them in ones that I host.
Well, the history of technology evlolution is filled with examples of concepts thought to be correct or incorrect at one point in time can be discovered to be the contrary in another point of time. Just look at many health and nutrition science which has a much shorter life cycle. I try to keep an open mind.
It does seem that any reflection caused by the guide/horn should show some null at approximately the same angle regardless of distance though.
It does seem that any reflection caused by the guide/horn should show some null at approximately the same angle regardless of distance though.
Tom Danley said:
Hi Tom and Earl,
it would be great if you could post the result of this measurement.
Thanks 🙂
soongsc said:
Seldom is an existing theory that has been proven and verified ever found to be wrong, it is usually found to be incomplete. A perfect example is Websters Horn Equation. Within the limits for which it was defined it is adequitly correct, but it is incomplete. It cannot account for effects that are not axial since it is a one-dimesional equation. In Websters time horns were used only for loading and this approach worked just fine. In directivity control this approach is totally inadequite.
I usually object when someone says to "keep an open mind" when I correct a mistake. Mistakes are mistakes, an "open mind" can't change that.
gedlee said:
Normally I would send this direct, via PM, but Earl "requested" that I not email him directly. So I run the risk to post here.
I was more than willing to let the whole thing drop, and not have anything further to say on the subject here, but I see it's still running.
Earl, who are you correcting? Rcw? He knows what he's talking about. His view on the subject is as valid or more-so than your own. He will at least look to different sources (yourself being one) rather than declaring himself the defacto expert on the subject, and rejecting anyone else observations.
Maybe you were correcting me, but I don't rate. I'm no expert here on acoustics, I've just made some reasonable comments based on what I know. There isn't any threat from me to corrupt "your" thread.
As far as mistakes go, you make more than your fair share. They are all here for anyone to review, plus in other threads. The water being compressed by sound waves was a good one though.
You stand by your own mistakes and defend them and get upset if someone dares to point them out, while you vigorously and sometimes brutally "correct" others.
I never say never, but this time I must. I'm done here (good riddance, I know). Any knowledge that's available here leaves a bad taste.
But you see - I wasn't wrong about water being compressible - it can carry sound as a compressional wave therefor it must be compressible. This is exactly my point. I don't think that I am the one who is not open minded here. You and RCW were both told on numerous occasions by numerous people that the incompressible claim was wrong, and still you persist in making it.
And for the record, I requested that he not send me any notes on the side because he was rude and profane in the one that he did send me and I don't have to put up with that. I welcome all polite notes on any subject and those who have E-mailed me will note that I virtually always respond.
And for the record, I requested that he not send me any notes on the side because he was rude and profane in the one that he did send me and I don't have to put up with that. I welcome all polite notes on any subject and those who have E-mailed me will note that I virtually always respond.
I think we should put this one to rest.
While Earl is technically correct, the ability to compress water is such that even with tremendous pressure, the molecular structure of the water will allow for only a minute amount of compression. If it is compared with the ability to compress air, the water is said to be virtually incompressible. I think we all understand this. If not, let google be your friend.
Can we move on now please?
While Earl is technically correct, the ability to compress water is such that even with tremendous pressure, the molecular structure of the water will allow for only a minute amount of compression. If it is compared with the ability to compress air, the water is said to be virtually incompressible. I think we all understand this. If not, let google be your friend.
Can we move on now please?
Cal Weldon said:
Well, you are either correct or not. And in this case Earl is.
Sound waves can only travel through medium in longitudinal (or compression) waves, transverse (shear) waves, or combination of.
Fluids cannot carry transverse waves by definition (it requires fixed molecular structure), hence they must be compresible. If they weren't, no sound would go through them.
QED
Not many great discoveries were made without mistakes along the road.😀 "open mind" to me means that I do not rule out possibilities until I have enough theoretical and measured data to prove otherwise. Additionally, an "open mind" to me is to not insist whether I'm right or wrong, but just putting out my experience and findings allowing others to explore on thier own if they wish.gedlee said:
Theoretical analysis is usually a good encouraging start, but never the final word. In the case with HOMs, I would say that CSD is one way of looking at it, especially if there are multiple indications of existence that do not relate with diaphragm modes.
I do not know of anything that is absolutely incompressible, usually for certain applications compressibility can be ignored. If there is such substance please provide some information, it might be of some use.
It all sounds like rubbish to me, but I am no engineer
some bike forks use air support fore the springs
And if air couldnt be compressed how would you get hard tires on vehicles
Is it really more complicated than that
But I actually find it very strange that this thread is stranded on this issue
some bike forks use air support fore the springs
And if air couldnt be compressed how would you get hard tires on vehicles
Is it really more complicated than that
But I actually find it very strange that this thread is stranded on this issue
tinitus said:
A lack of understanding of basic science.
Sound waves do not compress water. A compression wave creates low and high PRESSURE. PRESSURE, not compression is how sound travels through water.
Water can be pressurized, turn on the kitchen faucet to prove out this. Putting water under pressure is not the same as compressing it.
Simple, really simple. Grade school stuff.
Enough already.
That defies logic. I'm sure the compression is extremely minute but it must exist or the speed of sound in water would be infinite right? How do you account for the finite speed of sound in water?
dlr said:
How much energy does it take to compress water? Compare that to how much energy it takes to PUSH or displace water. A sound wave will quickly die (lose all of it's energy) if it has to compress water.
I didn't miss any classes.
What we need here is a 6th grade school teacher to explain this to you all. I'm getting sick of trying.
poptart said:
No it doesn't defy logic. Sound waves do not compress water. Period.
You account for the finite speed of anything by understanding that things in motion run out of energy.
Sound starts with motion, vibration. It travels through a medium in the same manner, by vibration. Drop a pebble into a pond of water and see the waves created. These are exactly the same as sound waves, except on a different frequency and amplitude.