Well, if you look through the past few months, I have posted more new data that anyone else. It's very healthy to see more people show their own variety of data instead of only quoting data from few individuals. Besides, I just plainly asked. If he does not show it, it's fine with me.gedlee said:
I don't see a fair comparison unless both were designed for the same frequency range and integrated into a system. Even then, we can never objectively say for sure which is better because different people will have different preferences.goskers said:Now we are talking!!
I would love to see a head to head with the LeCleac'h horn and a GedLee WG.
Who's taking bets as I'd like to make a wager
Well, I have already used my sim data with Earl's data to explain how to identify HOMs and how the foam helps reduce HOMs. I have also shown sims and measurements of a wave guide that I made showing a trend that is much different in terms of HOM content and directivity than the wave guide Earl has presented. As a matter of fact, very early in this thread I had raised the question on how to identify HOMs looking at data which was never answered prior to my findings in the course of all this discussion. So, please feel free to post quality data. I think when Jean-Michel points out aspects that I miss, it is done in a very precise manner, no personal attacks involved. This is what I think the most reasonable way to handle it. Earl has pointed out some valueable points in my sims as well. If there is anything I have missed, by all means point it out more specifically which post is being referred to so I can see if I missed anything or not.
I would have known better if I counted the elements before I started the run.
I might even be able to finish measurements before the sim is complete.
soongsc said:
If this data was presented then I missed it.
Please explain how you showed; "data to explain how to identify HOMs"; "how the foam helps reduce HOMs"; "a trend that is much different in terms of HOM content and directivity than the wave guide Earl has presented". And if you would please explain how any of this changes or refutes anything that I have said. Your sims are pretty pictures, but I have said all along that I don't see much useful data in them.
Bjorn supplied me with the complete set of simulations on the OS waveguide and on Jean-Michels horn. I will plot this as a polar map and show both, although Bjorns data still uses what is a suspiciuos throat to me.
I posted here,
http://www.diyaudio.com/forums/showthread.php?postid=1774677#post1774677
your response was here.
http://www.diyaudio.com/forums/showthread.php?postid=1774711#post1774711
Then I explained here.
http://www.diyaudio.com/forums/showthread.php?postid=1774992#post1774992
Basically when the SPL lines at different angles intersect each other back and forth we know there are HOMs involved. At a specific frequency, if the larger angle response becomes higher than the lower angle response, the larger the difference span over a range of angles, the more significant HOM is at that frequency.
http://www.diyaudio.com/forums/showthread.php?postid=1774677#post1774677
your response was here.
http://www.diyaudio.com/forums/showthread.php?postid=1774711#post1774711
Then I explained here.
http://www.diyaudio.com/forums/showthread.php?postid=1774992#post1774992
Basically when the SPL lines at different angles intersect each other back and forth we know there are HOMs involved. At a specific frequency, if the larger angle response becomes higher than the lower angle response, the larger the difference span over a range of angles, the more significant HOM is at that frequency.
goskers said:
sorry--keep getting confused...
i keep thinking this is about enjoying the experience of listening to music, not about seeing plots, and pointing @ them.
any isolated thing may (and does) help in getting there, but are not the only necessary component, or even necessarly THE IMPORTANT component.
the finger pointing at the moon, is still not the moon...
soongsc said:
I said that this wasn't true before and its not any more true now. For example, mouth diffraction will cause what you are talking about and it is not a HOM. There are many more ways that this can occur that are not HOMs. It is true that high HOMs COULD cause this, but you cannot conclude that HOM DO cause this.
And please explain how you showed : "how the foam helps reduce HOMs" and "a trend that is much different in terms of HOM content and directivity than the wave guide Earl has presented". I'm still waiting for those.
serenechaos said:
The point is that the subjective aspects that you keep wanting to bring up are meaningless and pointless. It's not that subjective aspects aren't important its just that they are not data and they aren't reliable - anyone can say anything that they want, especially here. So if you rely on subjective assesments then there is no point in having a discussion. Jean-Michel says "My horns sound best!" and I say "My waveguides sound best!". End of that kind of discussion. Its all quite pointless.
Real data is not pointless as it is what it is. If you are not comfortable with the fact that there is a high degree of correlation between good measurements and wide subjective appeal and perception, then this discussion is certainly not for you as that is the premis here. If you don't accept that premis then any further discussion on the point is unnecessary.
Well, I'm not ruling out the fact that mouth diffraction can cause it. But I think that mouth design integrated with the curvature starting before the first half of the wave guide will also change that. My sims and measurement data do not show mouth diffraction effects so much because I chose not to use a contant radius lip. The simulation data is there for anyone to study. Note that sim and measured data both show that the SPL at different angles do not cross back and forth as much. I have also provided listening impressions of the guides which I have posted data on. I cannot go into so much detail like a consultant. Further more, I cannot spend so much time on what I know will not help develop what I want. As you can see, I am not out to prove anyone wrong.gedlee said:
Soongsc,soongsc said:
If you are looking to do something which has your own direction to fit your own goals then I strongly urge that you start your own thread. If Dr. Geddes or anyone else has anything that they can help you out with or more importantly want to help you out with then they can do it there. I am sure many people want to see all of the excellent data that you have provided here without having to mine through this long thread riddled with useless information from Geddes.
I am posting here because of a few reasons: 1. I started out inspired by contents in this thread. 2.A small part uses an OS type expansion. 3.Results of studies seem to show that many things are quite different from those claimed what the OS wave guide will do. 4.The subject name suggests coverage of all aspects of wave guides, and thread content covers discussion of a variety of wave guides.goskers said:
If more new data proves that Earls is correct about OS type design having the least HOMs with measurement data to explain it, then I will agree with this portion. I have not objection to his embracing the importance of what is referred to as "constant directivity".
Portions of study that relate with the LeCleach type expansion will not be published here.
Re: speculation is not pointless
I was curious about this, and actually started out using the hyperbola merge with the baffle. This eventually lead to discover that curved sides also tends to reduce HOMs. What kind of sacrifice in directivity control really needs to be studied further. This is also why I think that without a more specific and quantified definition of "constant directivity" will just confuse the issue the way lack of interfacing standards plague the cable issue.
Hi Ed,Ed LaFontaine said:soonsgc posted:
from post 11:
which was responded to by Dr. Geddes in post 14:
Dr. Geddes didn't say the fillet was "better", just a matter of choice.
I'll speculate this is progress...
I was curious about this, and actually started out using the hyperbola merge with the baffle. This eventually lead to discover that curved sides also tends to reduce HOMs. What kind of sacrifice in directivity control really needs to be studied further. This is also why I think that without a more specific and quantified definition of "constant directivity" will just confuse the issue the way lack of interfacing standards plague the cable issue.
soongsc said:
If so, then it would seem that you are not doing an OS of any sort. I don't see how it can be "part OS". Either it is or it isn't.
Whose studies and how competent are the results? Have they been documented and proven? This is a rather nebulous claim. Which claims do you contest? Be specific with details, since you're the one making the counter claims.
This is flip-flopped, at this point it is in your court to disprove with more than nebulous claims. Where is your published data and theory? Until you can provide any acceptable, proven data that contradicts competently, remaining skeptical is one thing, making unproven claims of contradiction with incomplete, unproven data and hypotheses is unprofessional and a bit rude.
From a couple of the posts on measuring HOM that would require some rather elaborate testing schemes, my take is that you do not have the measurement capability to separate and distinguish HOM from the other aspects. You are using conjecture and hypothesizing in that regard.
Dave
I'm not claiming to be best, but I sure hope others show better data than I have. I'm sure the more data from various origin show up, the clearer picture we have. The sad fact is that there is not even data showing that the OS will have a spherical wave front at all frequencies in the range it is designed for.dlr said: