Yes, I am sorry for the slam.
But maybe I should have taken pains to have said in more words, "in a rational universe, vendors would offer relevant evidence for their claims." Granted, you and Toole have concluded, no doubt correctly, that collecting the evidence would be difficult. Never the less......
As a guy who can't understand why anybody would try to reproduce air waves by shoving a heavy block of cardboard back and forth, I can only marvel at the depth and heat being applied here to issues of directivity. I would be far more sympathetic to the effort of this thread if I were convinced by human test data that it made an aural difference.
Last edited:
I changed my mind. Maybe it is SIMPLE to test. What if we took pairs of directivity-designed speakers (behind curtains, double-blind, etc.) and toed them to the walls or toed them cross-eyed, or you get the idea.... and got various humans to make various human judgments, ratings, pointings, etc.
Seems simple enough. Like all experiments, the pattern of results might be adequate to prove or to disprove some "hypothesis" but not able to prove or disprove all hypotheses.
Seems simple enough. Like all experiments, the pattern of results might be adequate to prove or to disprove some "hypothesis" but not able to prove or disprove all hypotheses.
Last edited:
bentoronto and thomas jefferson, your questions make it clear you haven't read the thread. bentoronto, your posts are especially puzzling because you mention Floyd Toole as an example of what we should be talking about when his work IS exactly what we are talking about. If you read the thread (or the measurement thread, they're getting to sound the same) you'll repeatedly see the statement that if you haven't read Floyd Toole's book you don't have the background information to understand that these aren't some random assumptions. You should make an effort to educate yourself about what work HAS been done investigating these issues before telling us that nobody is doing any and you think that's silly.
Last edited:
What evidence are you asking for. Measurements exist? what else do you want?
Subjective listening preference? That is for audiophiles. I just want technically superior designs. I will EQ them in room to my specific listening curve.
It is correct to say that nobody has clearly sorted out scientific data. Whether anybody knows or not remains unknown. However, if we combine the knowledge of the strength, delay, and masking effects, one can get a better knowledge of what is involved. Much of the pieces of knowledge is out there. It's really a difficult task to link all the information together and present it in an understandable manner.
Last edited:
I can only say that I do offer up as much supporting evidence as can be found, its on my web site. There is a multi-page document outlining the hypothesis that I use in my designs. It is hardly random, yet, admitedly, it is not conclusive either.
I just hope that you don't "hold your breath" or not buy speakers, waiting for this conclusive evidence to come along.
I proposed that precise test to Floyd, he was not so inclined to think it useful. With my speakers there would be a marked difference in the reflection pattern, but no difference in the direct sound, if they face in or face out.
But here is the thing, they will sound completely different - I hazard to guess that much is clear - but after that then what? The single biggest criticism of Floyds work has been that it is based on preference and preference is not necessarily accuracy. Preference leans heavily towards spaciousness, while accuracy leans heavily towards imaging. Floyds work is very superficial on imaging and heavily weighted towards spaciousness. This stems in no small way from his "preference" for "recreating" a sound field as "would be "heard in an auditorium. But vast amounts, if not the vast majority, of recordings do not target this "perception". So this, in and of itself, presents a problem.
In all of Lidia and my work we dealt with "audible" versus "nonaudible" there was always a reference signal that the listener had to use as a comparison. This makes for very clean (well relatively clean) data. When you start asking the "prference" question where there is no reference, things get dicy.
Floyd and I agreed to try and pursue some testing of "directivity", but in the end it ended up being one of those things that there just wasn't the time and resources to do.
Finally, a friend of mine recently ran a blind test of speakers in rooms and asked a number of "human" questions. In the end, after weeks of work, he had to conclude that there wasn't any statisticaly valid result - in other words the test bombed. Ouch!! I was asked to participate in the test both as a listener and to use my speakers. I declined because I did not like the assumptions of the test. I knew that anything could happen, and didn't want to be part of that.
So while your "concerns" are admirable, those of us who have done this for decades realize that its not that simple. If it were, then surely it would have been resolved by now. I think that many of your comments do reflect a certain nievete about this situation. I admire your desire to know "only the facts", but please don't criticize situations that you really arn't that aware of, because there may never be a set of facts to your liking.
I don't think so. (..at least with respect to marketable product.)
There are any number of *practical* limits to the basic design AND consumer acceptance.
Toole's work didn't just "curve fit" spaciousness in small rooms, it "curve fit" industry standard speakers IN RELATION to spaciousness in small rooms.
Surround sound in the home had this same problem.. and it wasn't a problem of amplifiers or processors, it was loudspeakers (their basic size/design/cost) and consumer acceptance. In fact it wasn't until Bose.. yes Bose, started marketing their little satellite/sub system that both producers and (large segment) consumers said: "yes, I think I could tolerate those additional speakers in my home".
Last edited:
I think the picture is becoming pretty clear. Much talk. Little evidence. Anybody think otherwise?
Even "experiments" that would take 90 seconds to set up during a trade show.... too hard to do.
Earl, very nice of you to allow for my ignorance and naivete esp. as you put it, compared to exceptional persons like yourself - "those of us who have done this for decades."
Even "experiments" that would take 90 seconds to set up during a trade show.... too hard to do.
Earl, very nice of you to allow for my ignorance and naivete esp. as you put it, compared to exceptional persons like yourself - "those of us who have done this for decades."
Last edited:
Little evidence?? Are you measurement and mathematics disfunctional?
What you are asking for is subjective evidence which is 100% pointless IMO. Having superior measurements backed by mathematics is a great start. What someone likes is meaningless because most people do not have a clue or are stuck with a long history of listening to designs that produce inaccurate response curves.
I think most people doing DIY waveguide builds are doing them because of Dr. Geddes. There has been an exponential increase over the past couple of years and we have his research to thank.
I have to ask why are you posting in this thread if you are not interested in waveguides??? Are you next going to tell us ESL designs are remotely good?
No thanks, some of the worst dynamic crap in the world is label ESL.
As for trade shows? Who cares...this thread isnt about Geddes selling his speakers. He already knows there isnt enough profit in the audio business compared to other parts of his career. Why do any setup at a trade show when profits are slim anyways?
The majority of people seldom buy on superior measurements and performance. There are so many other factors that matter. Audio science is way down that list.
If you want subjective proof. One only needs to go to a couple of DIY events and listen to some of the best waveguide designs out there to realize how good something can sound. You can also look up any owner of Geddes speakers or Duke's Audiokenesis speakers to know they are not your average speaker.
Have you heard waveguide designs?
What you are asking for is subjective evidence which is 100% pointless IMO. Having superior measurements backed by mathematics is a great start. What someone likes is meaningless because most people do not have a clue or are stuck with a long history of listening to designs that produce inaccurate response curves.
I think most people doing DIY waveguide builds are doing them because of Dr. Geddes. There has been an exponential increase over the past couple of years and we have his research to thank.
I have to ask why are you posting in this thread if you are not interested in waveguides??? Are you next going to tell us ESL designs are remotely good?
No thanks, some of the worst dynamic crap in the world is label ESL. As for trade shows? Who cares...this thread isnt about Geddes selling his speakers. He already knows there isnt enough profit in the audio business compared to other parts of his career. Why do any setup at a trade show when profits are slim anyways?
The majority of people seldom buy on superior measurements and performance. There are so many other factors that matter. Audio science is way down that list.
If you want subjective proof. One only needs to go to a couple of DIY events and listen to some of the best waveguide designs out there to realize how good something can sound. You can also look up any owner of Geddes speakers or Duke's Audiokenesis speakers to know they are not your average speaker.
Have you heard waveguide designs?
Last edited:
Great results by any standard, John !
Would like to see more of this current work of yours - maybe on an own thread ? - some pix and some comments, whatever ...
Michael
Many of the most respected scientists of the 19th century would be in the fullest agreement with your thinking.
No, I have never heard a Geddes speaker. I regret that and I would gladly travel within reason to hear them in the Toronto region. Help me find some and in a good listening environment.
But I have heard a great many two-way systems. In fact, when I was at the famous Bell Labs in Murray Hill, New Jersey, two-way KLH-6s were the lab standard speaker for the scientists in my division ("Human Information Processing and Music," if I recall).
Ah, 1967 was a wonderful year at Bell.
Thirded. I'm a pretty decent mix of engineer and builder but some of our guys (Earl, John) make me look like a piker.
In continuation of the wave guide posted here,
http://www.diyaudio.com/forums/multi-way/103872-geddes-waveguides-423.html#post2162280
http://www.diyaudio.com/forums/multi-way/103872-geddes-waveguides-425.html#post2196251
http://www.diyaudio.com/forums/multi-way/103872-geddes-waveguides-425.html#post2196636
I have finally slipped in some time to extend the baffle of the wave guide beyond the lip to a round baffle with a diameter of 40cm. I should be doing some measurement either Friday or the comming Monday. Are there any guesses what this will do to the response? The curves up to the blend with the baffle remains the same. The diameter of the WG where is blends with the baffle is about 22.5cm.
http://www.diyaudio.com/forums/multi-way/103872-geddes-waveguides-423.html#post2162280
http://www.diyaudio.com/forums/multi-way/103872-geddes-waveguides-425.html#post2196251
http://www.diyaudio.com/forums/multi-way/103872-geddes-waveguides-425.html#post2196636
I have finally slipped in some time to extend the baffle of the wave guide beyond the lip to a round baffle with a diameter of 40cm. I should be doing some measurement either Friday or the comming Monday. Are there any guesses what this will do to the response?
The curves up to the blend with the baffle remains the same. The diameter of the WG where is blends with the baffle is about 22.5cm.
Last edited:
We all think otherwise but you seem pretty determined to ignore the evidence (as well as my previous post) so there's not much we can do for you here.
Really, my 9th grade classmate was a distributor of those back in 1975 if I recall correctly.
I thought your suggestion that I read through 4,500+ posts was disingenuous.
def. of disingenuous
Ummm, be sure to read the interesting "usage note."
Seems to me, if you had a few really knock-out boffo references from a peer-reviewed or otherwise non-commercial or neutral source, you would have tooted them from the rooftop, instead of providing the kind of rude "get the heck out of town by sundown" response that you provided. And feeling the urge to post it TWICE.
soongsc - I could easily be mistaken, but I suspect I've got your point about two-way speakers.
Last edited: