Geddes on Waveguides

BHTX said:


Imagine being born today, and getting into this hobby 20 years or so from now, taking into consideration what's been previously said. I don't think one can argue that things would be little different, and perhaps quite a bit more difficult?

The same thing that got me into it would drive the newcomer. Compared to the live experience the reproduced sound is unsatisfactory. And there are the professional and amateur musicians who need better sound. They will go looking for solutions.

Will their search be more difficult? I suspect it might be easier. Research and products such as Earl's and of some of his competitors will be more widely disseminated and possibly in a more accessible fashion. It's easier now to find information about good sound reproduction than it was 10, 20, 30, 40 years ago. I know this because I was looking back then.

There are high school and university age people participating here at diyAudio and a heck of a lot more of them at the semi-pro music sites.
 
That's the kind of response I was expecting, unfortunately.

While I agree with much of what has been said, I tend to view the big picture a little differently..

I, for one, have actually really enjoyed listening to loudspeakers of all different types of designs, as well as the small bit of building I've actually done. Isn't that what makes DIY audio so enjoyable in the first place? For me, staring at charts and graphs all night is the dreadful but often necessary part of the process.

As far as what "marketing people at the large companies want me to believe", they don't "manipulate" me much, personally. You're preaching to the choir on that one. After all, this is diyaudio.com, and I'm here to avoid that in the first place, while constructing something better for my own enjoyment.

On a side note, adding to the discussion of automobile preferences, I also enjoy working in the garage on my big, bright, attention grabbing hot rod and driving it to the lake on the weekends with family/friends.

In the end, it really IS what I like that counts, and I wouldn't have it any other way. If DIY consisted of nothing but objective data, I would have been completely turned off at the thought of it. Same goes for anything else. Science is very interesting indeed, and can even be somewhat enjoyable at times, but it'll never become the ONLY priority within EVERYONE'S hobbies. Same goes for staring at endless dreary talk and data from highly sophisticated individuals with corresponding egotism. I'm not sure about anyone else, but if I was forced to rely on this as the basis of my hobby, I'd give it up in a heartbeat. I honestly don't see how anyone could consider themselves satisfied with what they're doing with their leisure time, otherwise. And for me, that's just what it is.. "free time", and I suspect it HAS to be the same way with others around here. Once again, that's why it's called D-I-Y. But perhaps I've already been proven wrong. Just look at this place already..
 
intersting conflicts

It is interesting that this IS a DIY website... this thread is in the DIY loudspeaker section (not the Vendor's section), yet the DIY aspect of building one's own OS waveguide system (for whatever that would be worth should one want to) seems to be actively (if indirectly) discouraged wrt the particulars of what is purported to be THE solution to CD speakers. (much too complicated, hard to make, that sort of thing)

hmmnnn.,.. wonder why that is

John L.
 
Re: Re: intersting conflicts

ShinOBIWAN said:
Hey John,

Its technical discussion though and that's always welcome IMO. There will be opinions and preferences expressed but people can read into those what they will.

Dunno about the technical content of the last several pages ... but I agree that some aspects of the posts have been enlightening, if only some of the atitude could be eliminated.

Look at all the whining about OB hijacking the CD discussion of the threads a few mos. back... I decided to just go away while that was going on.

As far as dismissing personal preference as a rationale for purchasing (fill in the blank), that would seem to presume all the definitive variables have been sorted out. Room interactions and constraints, for one, seem to be little understood applied to individual setups, giving me pause, at least, to rote acceptance of theory over emprical experience.

John L.
 
auplater: I think I see what you're getting at. On one hand, it makes perfect sense, a great idea even. On the other hand, it doesn't. Personally, I'm still not entirely convinced in regards to the possible ulterior motives you seem to be referring to. I'll just leave it at that. :)

ShinOBIWAN: Of course! If it weren't for technical discussion, I wouldn't have acquired a recent interest in things like horns. Obviously, I think it's probably safe to say that audio reproduction as a whole wouldn't exist if it weren't for the sharing of technical information. And indeed, without so many opinions and preferences, this hobby wouldn't be so interesting. Well, to me at least..
 
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Joined 2001
Paid Member
The subject of how to make a waveguide has come up and the answer was that it is pretty easy to figure out from reading the threads on the topic. There are spreadsheets available to calculate them. But I agree, it would be nice to have the whole process and information in one place. Maybe a new thread? I would assume, given the opportunity we have given him here to mention his ideas (and DIY kits) that Geddes would drop some hints if they were required.

I posted a link to a paper by Peavey that tells how to make a waveguide that is a compromised design, according to Earl, but apparently gets part of it right.. and its square shape would make DIY easy..


I would very much like to see posts that give examples of a particular section that could be used to make a particular waveguide- and some examples of waveguides that members have made.. and comments on their sound..

If DIY is the idea, then it is up to the DIYers to do the work-and post about it. That's what DIY means!!
 
waveguides

In my past pre-medical life, I built microwave waveguides of all kinds of imaginable (and some not-so-imaginable) structures for NRAO, Bell Aerospace, JPL. Built them, not designed them.

Since these weren't sound waveguides, and I certainly don't have experience with waveguide design, but lots of mfg. experience (and interest in speaker building and designs), I was naturally drawn to the waveguide discussion, only to be dissapointed that more technical information was not forthcoming in an easily accessible manner for fabrication of such setups.

John L.
 
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Joined 2004
Re: waveguides

auplater said:
Since these weren't sound waveguides, and I certainly don't have experience with waveguide design, but lots of mfg. experience (and interest in speaker building and designs), I was naturally drawn to the waveguide discussion, only to be dissapointed that more technical information was not forthcoming in an easily accessible manner for fabrication of such setups.

John L.

Agreed, I've been casually following this thread myself but I still wouldn't fully know how to build my own waveguide according to the recipe that Earl has cooked up.

Maybe I'm dumb? :D
 
I have said this before, but I can see that I need to say it again. I am not a speaker hobbiest, it is my profession, and building speakers is not my passion, listening to music is. In other words I am not a DIYer, hence, it really all boils down to the simple fact that I really shouldn't be here. I am more than willing to go away if this situation is not deemed desirable, but I am certainly NOT going to appologize for being an expert and having a commercial interest. If my presence here is desirable then you have to take that for what it is worth, the good with the bad.

I know that most people here want me to stay but that there are others who would have me go elsewhere as I "don't fit". But the fact is that I have something to offer and if there is an interest then I'll stay. If you don't like what I am offering then maybe my threads are not for you.

As to actually making waveguides, I have published everything that you need to know to design one, but I am not going to make it cookbook, and admittedly its not that easy (but its not that hard either). As to fabricating them, there are some trade secrets about my new process that I am afraid I have to keep to myself. Thats just the way it has to be.
 
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Joined 2004
gedlee said:
As to actually making waveguides, I have published everything that you need to know to design one, but I am not going to make it cookbook, and admittedly its not that easy (but its not that hard either). As to fabricating them, there are some trade secrets about my new process that I am afraid I have to keep to myself. Thats just the way it has to be.

Ah! As I thought, I'm dumb. :)

You really ought to reconsider and make your ideas more accessible. I know your here sharing already but a little dumbing down with a comprehensive 'how to' would certainly help more people build and implement these. It would probably also provide a little less resistance to your ideas and claims at the same time or maybe not. I bet 90% of folks in this thread haven't even heard what one of your waveguides sounds like let alone measured one.

You've made it clear that your here to promote and indulge in your ideas more than promote those same ideas becoming available to the masses. Some would disagree but I don't really agree with that on the whole but hey, thanks for sharing what you have so far.
 
Posted by Dr Geddes on the "Beyond" thread.
Post #3182
All

A few key points to be made.

The OS waveguide contour is public domain. The Bi-speriodal has an issued patent.

The use of foam in a waveguide is patent pending and has been through its first office action. Based on that I can say with certainty that 1) it will issue, and 2) it will cover most uses of foam or other materials placed inside of a horn or waveguide.

As to the Declerq comparison to the OS, I would say this. I have not seen anyone do an OS waveguide right (myself excluded of course) so very very few people have heard what they can do when done correctly. Lynn seems to be impressed with what hes heard with the Declerq, but he has, at best, heard an OS only for a brief period in a less than optimal setting. And Yes, OS's can be used without foam, but why? I give a license to use any foam plug that I sell. You just can't use one that you don't buy from me. Thats fair, isn't it?

While the OS contour is not patented there are an awful lot of trade secrets that I do to make these devices work to their full potential.

I have heard a lot of horns and systems and all I can say is that I would put my designs up against anything out there for sound quality at high output levels. There simply is nothing that I have heard that can compare - and I'm talking at any price - Avantgardes, JBLs, TADs.

I have been very busy with another 'invention" that the manufacturers are eating up. Haven't been around here much. Not likely to get less busy in the near future either.
 
Well I guess that I am missing these points.

There is very little that I have not shared here and far more than any other waveguide designer in the field. What I fail to understand is why people want me to repeat here things that are in print elsewhere. And then repeat them again for the guy who just got on board the thread. This is neither efficient for me or reasonable.

Waveguides can be difficult to make, to wit an elliptical one as even I have not the time or resources to do this.

I fail to understand what it is that I am expected to do. Design loudspeakers for anyone who asks? Is that reasonable? Where is the point beyond which I am being asked for "too much"?
 
ShinOBIWAN said:
Earl I think what John and I were getting at was consolidating and simplifying the information to make it more accessible. Nobody is demanding this from you, but you'd be doing the community a favour if you at some point you choose to do that.


Assuming the "simplification", more that it already is, is possible. As for "consolidation", the most complete and comprehensive discussion that I know of is chapter 6 in my book. I have attached it for your interest. Is it simplified? No.

As I thought about it I have to conclude that actually making a waveguide is beyond most DIYers. Turning one on a lathe is the easiest, but as many people will tell you that is a very time consuming task, and then you get one! When I first tried making my own waveguides I destroyed about four molds before I got one. Without some advanced knowledge of dealing with fiberglass and mold making it is simply not possible to do effectively. John VanOmmen does it and he'll tell you that it is not for the causual DIY. It takes significant expertise, and lots of time at very messy and smelly work. That is why I make for people, so they don't have to do it.
 
ShinOBIWAN said:
Earl I think what John and I were getting at was consolidating and simplifying the information to make it more accessible. Nobody is demanding this from you, but you'd be doing the community a favour if you at some point you choose to do that.
I agree with this statement, but I also agree with Earl that he has already given enough info out to work it out on your own should you chose.

It seems to me there is a similarity with Tom Danley and the Unity here. Lots of people, me included, would like a simple DIY recipe, but I have a large collection of his posts on various fora and have nearly got a handle on how to do it myself. There is no benefit to Tom to do the DIY recipe, and he has been generous with his info and time and effort, especially around the LABhorn. All the same can be applied to Earl and the OS WGs.

Several years ago quite a few of the high efficiency fans wanted round tractrixes. I can think of maybe a dozen people who went to the effort of turning one up. I had mine made by someone else, and it was no mean feat to find someone who could do it to the required tolerances.

It seems there is a Bell curve to DIYers: some want a simple kit and some will do all the research and experimenting to do it themselves. Then there's most of us on the hump in the middle.

I've just bought several of Earl's WGs. I could have them made here, but it was easier to buy them, the exchange rate makes it cost effective for me at the moment and I wanted to support Earl in the info he has provided.