I agree with Earl's charactarization of Chapter 6 of his book. I don't get any compensation for saying "read Earl's book if you're serious about understanding waveguides", so coming from me it can't be construed as an ad.
If "Transducers" is too intimidating, then read his other book and his posts on this forum and elsewhere on this website. His posts here contain a genuine wealth of knowledge, most of it translated into minimally-technical language, and it's literally right at your fingertips.
If readers are looking for politically correct self-deprecation, this is probably the wrong thread. If readers are looking for the embodiment of first-rate acoustic and psychoacoustic research, this is the place - but you may have to put aside some of your instinctive emotional reactions to get the full benefit from it. If you let your objections to Earl's choice of words get in your way, you will be missing out on the chance to learn from one of the real masters. You don't realize how lucky we are. This is like having Frank Lloyd Wright posting on a DIY architecture board, but before his work was widely appreciated.
In my experience, Earl's waveguides and crossovers are extremely low in audible distortion. His waveguides are the lowest in audible coloration of any such device that I have experienced, and his science has earned my highest respect.
Duke LeJeune
If "Transducers" is too intimidating, then read his other book and his posts on this forum and elsewhere on this website. His posts here contain a genuine wealth of knowledge, most of it translated into minimally-technical language, and it's literally right at your fingertips.
If readers are looking for politically correct self-deprecation, this is probably the wrong thread. If readers are looking for the embodiment of first-rate acoustic and psychoacoustic research, this is the place - but you may have to put aside some of your instinctive emotional reactions to get the full benefit from it. If you let your objections to Earl's choice of words get in your way, you will be missing out on the chance to learn from one of the real masters. You don't realize how lucky we are. This is like having Frank Lloyd Wright posting on a DIY architecture board, but before his work was widely appreciated.
In my experience, Earl's waveguides and crossovers are extremely low in audible distortion. His waveguides are the lowest in audible coloration of any such device that I have experienced, and his science has earned my highest respect.
Duke LeJeune
audiokinesis said:
and mine! Absolutely! Dr Geddes is a great interlocutor! I love those online discussions with Him.
My highest respect would be even higher and also my deep gratitude would be even deeper if Dr Geddes kindly answered my humble waveguide related questions instead of choosing to ignore me
but I really cannot complain!
after all - who am I to complain?
Therefore I am not complaining - just asking
best regards,
graaf
I must agree that Dr. Geddes does point out many inspiring issues, and in many of his posts in many threads, would never hesitate to point out what is wrong in a very straighforward manner. Personally, I appreciate this kind of communication. However, understanding what's going on, and providing a means of predicting a result are different issues. One is understanding of the physical phenomenon, the other is developing a methematical means to predict results based on understanding of the phenomenon. Just like discovery of gravity and developing means to predict what gravity does to objects. If his book does indeed provide the mathematic means to predict HOMS and directivity control for axisymmetric and/or non-axisymmetric designs, then the book would be a must for designers.
audiokinesis said:
This pretty much mirrors my thoughts, word for word.
Also, every time Dr. Geddes posts a new thread, or even a single message.. I can't help but wonder if it'll be his very last contribution to this forum. It's a shame really. All of us interested and supportive folks would miss out, as a result of other people's childish ignorance and disregard.
Brett said:
+2 Duke.
Sorry I missed all this. Thanks for the support.
Graaf - I gave you the answer that you are going to get. You didn't like it and kept asking. I didn't ignore you, I'm just not going to answer the same question over and over while you hope the answer will change.
Magnetar - haven't you figured out as yet that I won't answer posts from you which are not polite.
Graaf - I gave you the answer that you are going to get. You didn't like it and kept asking. I didn't ignore you, I'm just not going to answer the same question over and over while you hope the answer will change.
Magnetar - haven't you figured out as yet that I won't answer posts from you which are not polite.
Dr. Geddes,
Several pages back, you pointed out the importance of matching directivity at the crossover point. After modeling several horns and wave guides in Hornresp, I now have a higher appreciation for why you use a direct radiator below your wave guide. Matching the directivity to a direct radiator is much easier than matching between a pair of horns, or a horn and wave guide. Just as you said, the wave guide size can become quite ridiculous in size. However, I believe I’ve found a combination that is reasonable for “Me”. Below are the directivities of a purposed tractrix mid-bass horn and mid-range OS wave guide. Interesting enough, the tractrix was the only horn type that would beam enough to get a reasonable crossover point. Lemonade from lemons.
The half size 112Hz tractrix is 27” in diameter at the mouth. The OS wave guide is 20” in diameter at the mouth and 10” deep. I would forgo all this, but I really like horn mid-bass and have never found a direct radiator that could match a horn’s dynamics.
Thanks for you continued insights on wave guides. I now see how badly the directivity is mis-matched in multi-horn installations. It’s been a real eye opener.
Rgs, JLH
Several pages back, you pointed out the importance of matching directivity at the crossover point. After modeling several horns and wave guides in Hornresp, I now have a higher appreciation for why you use a direct radiator below your wave guide. Matching the directivity to a direct radiator is much easier than matching between a pair of horns, or a horn and wave guide. Just as you said, the wave guide size can become quite ridiculous in size. However, I believe I’ve found a combination that is reasonable for “Me”. Below are the directivities of a purposed tractrix mid-bass horn and mid-range OS wave guide. Interesting enough, the tractrix was the only horn type that would beam enough to get a reasonable crossover point. Lemonade from lemons.
The half size 112Hz tractrix is 27” in diameter at the mouth. The OS wave guide is 20” in diameter at the mouth and 10” deep. I would forgo all this, but I really like horn mid-bass and have never found a direct radiator that could match a horn’s dynamics.
Thanks for you continued insights on wave guides. I now see how badly the directivity is mis-matched in multi-horn installations. It’s been a real eye opener.
Rgs, JLH
gedlee said:
It seems he's having some difficulty with that.
http://www.diyaudio.com/forums/showthread.php?postid=1554759#post1554759
different mouth distance
hi John
i have drawn a tractrix lower midrange horn with 27" size at the mouth, and a oblate spheroid midrange horn with 20" mouth, and 10" deep. When the two horns are time aligned, the vertical mouth distance one to the other is about 13". How might this discrepance affect the perceived sound and integration of the two channels ?
Angelo
hi John
i have drawn a tractrix lower midrange horn with 27" size at the mouth, and a oblate spheroid midrange horn with 20" mouth, and 10" deep. When the two horns are time aligned, the vertical mouth distance one to the other is about 13". How might this discrepance affect the perceived sound and integration of the two channels ?
Angelo
Hi JLH, i wonder if the distance between both horns will lead to increased interference, lobing, combfilter effects. Gedlees speakers have a smaller distance between both sources. I dont know guidelines to figure out if this is a problem in this case, so if someone knows better, please clarify.
Respect?
Well, a book doesnt impress me none, many people writes books these days and I probably wont understand half of it
Knowledge, well I respect that depending on how its presented
Modesty is said to be a virtue, on the other hand, skilled people should be allowed to be self confident
What I do respect is Earl Gedlees ability to get these kits together in a very short time frame ... obviously a man who gets things done ... I respect that
And not to forget ... without being too greedy either
Enough said, had to get it off my chesst
Earl, there are some spunky fighsty kids in here, dont take it too seriously ... they are bored and only want to have some fun
Please ignore and continue discussion
Well, a book doesnt impress me none, many people writes books these days and I probably wont understand half of it
Knowledge, well I respect that depending on how its presented
Modesty is said to be a virtue, on the other hand, skilled people should be allowed to be self confident
What I do respect is Earl Gedlees ability to get these kits together in a very short time frame ... obviously a man who gets things done ... I respect that
And not to forget ... without being too greedy either
Enough said, had to get it off my chesst
Earl, there are some spunky fighsty kids in here, dont take it too seriously ... they are bored and only want to have some fun
Please ignore and continue discussion