What happened was that a lot of people built horn or hybrid horn systems very much to their liking, inspired and informed by the discussion here. I know because I made a quite a few 420 Azurahorns for them and got reports back. I expect many of these systems are still evolving as people learn from the experience.
best wishes to all, and thanks Lynn,
martin
best wishes to all, and thanks Lynn,
martin
I think Lynn is just being his usual meticulous self. He may have added the second bass driver (to increase sensitivity) and is spending time re-balancing the system, or it could be, as has been said, that horn systems just take longer to get the balance right. I am curious too, but will wait patiently. Lynn, OTOH, an update would be much enjoyed, pretty please?
Deon
Deon
Lynn Olson post ("I do not give great weight to directivity control. I know that Dr. Floyd Toole and Dr. Geddes place directivity control high on their list of priorities, but I must respectfully disagree with them, while agreeing on many other points. I very strongly agree about the importance of uniform and flat response at the listening position...")
Dr. Geddes has performed extensive measurements on controlled directivity and polar response to school us why his Summa OS-waveguide speakers use just a 1" diameter compression driver tweeter. It is necessary(but not sufficient) for a speaker to measure good to sound good. It seems that Dr. Geddes believes the coherent polar response from just one horn all the way up to 20KHz is more important than the higher dynamics from a larger diameter compression driver mid-horn plus crazy placement supertweeter.
Many multi-horn speaker designs seem willing to accept a known "crazy tweeter placement" in favor of 1.4" or 2" compression driver dynamics on a large horn. The stereo illusion is just a Jedi mind trick anyway ... "That is not the horn you are looking for", said Obi-Wan.
I wonder if Lynn will find that a crazy placement RAAL ribbon tweeter next to a 1.4" CD is not as COOL as a Be diaphram on the 1.4" Radian CD.
Dr. Geddes has performed extensive measurements on controlled directivity and polar response to school us why his Summa OS-waveguide speakers use just a 1" diameter compression driver tweeter. It is necessary(but not sufficient) for a speaker to measure good to sound good. It seems that Dr. Geddes believes the coherent polar response from just one horn all the way up to 20KHz is more important than the higher dynamics from a larger diameter compression driver mid-horn plus crazy placement supertweeter.
Many multi-horn speaker designs seem willing to accept a known "crazy tweeter placement" in favor of 1.4" or 2" compression driver dynamics on a large horn. The stereo illusion is just a Jedi mind trick anyway ... "That is not the horn you are looking for", said Obi-Wan.
I wonder if Lynn will find that a crazy placement RAAL ribbon tweeter next to a 1.4" CD is not as COOL as a Be diaphram on the 1.4" Radian CD.
. . . For what it's worth, and by all accounts, the dynamic capability of the Summa (both measured and perceived) is well beyond anything that would ever be reasonably required in a listening room.
It's possible that folks pursuing even greater headroom are doing so because they are hearing HOM's, which can easily create the perception of insufficient headroom. In reality, the drivers are just fine, and the distortion is due to diffraction. Im sure there are other preference reasons as well.
Lynn himself has heard and commented on the Summa somewhere in this infinite thread. Perhaps he will comment per the current context.
-- Mark
The SEOS "waveguides" (like gedey uses) I have sound bad in my room compared to even some ancient horns like the JBL 2350. They don't really load so they have a hard time keeping up in a filly horn loaded system in micro and macro dynamics. I don't think it's a CD issue with the SEOS because I can get similar pattern control with other horns. I think it's because they are poor at loading the driver and sound weak and anemic compared to a real horn. Maybe when used with less efficient woofer as a direct radiator it is not so obvious. I tried that with a pair of good 15's and it was OK but very difficult to live with compared to horn loaded bass with real horn upper range.
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In all fairness, most horn cabinets (or wave guide, if you insist) will have good to great dynamics. That is pretty much the advantage of a horn (front loaded, compression loaded). Even an average design will do that fairly well. It may have another problems, but that is another topic.
IThe SEOS is similar to yours but with less interference from lobing due to the shorter profile allowing closer positioning to the bass driver on the baffle. The point is it doesn't load the driver like a horn, yours or "SEOS."
Pooh,
Where do you get this idea that horn length changes take the basic function of a horn away? Whether it is an old Altec, JBL, or a newer design by Gedlee or the Seos has nothing to do with the fact that they have to follow the same basic physics. Yes the frequency that they're loading may be directed at and the frequency response and polar response may change they are all working as waveguides. To say that any of these designs does not load the driver is folly, without a proper load any compression driver will soon fail due to over excursion if any real power is applied to the device. Mouth size and flare rate have everything to do with loading of the device. You are only shifting frequencies and polar response. If you don't understand that you have no real understanding of a waveguide.
Where do you get this idea that horn length changes take the basic function of a horn away? Whether it is an old Altec, JBL, or a newer design by Gedlee or the Seos has nothing to do with the fact that they have to follow the same basic physics. Yes the frequency that they're loading may be directed at and the frequency response and polar response may change they are all working as waveguides. To say that any of these designs does not load the driver is folly, without a proper load any compression driver will soon fail due to over excursion if any real power is applied to the device. Mouth size and flare rate have everything to do with loading of the device. You are only shifting frequencies and polar response. If you don't understand that you have no real understanding of a waveguide.
The waveguides are only a few inches long, it does not load the driver like for example a JBL 2350 or a 300 Hz flare rate tractrix horn. as Gedlee, he'll tell you the same thing. How is a 6" deep 12" diameter "waveguide" going to load a driver like a 12" diameter 14" deep tractrix horn? It won't and it don't. I happen to prefer the horn over these short waveguides, pick your poison.
Waveguide and horn are only a semantic difference and can be interchanged. Even a short 1/4" front plate on a dome tweeter is technically both a horn and waveguide. As I said it is only the frequency and the pattern control that is being changed, not the basic physics of how they work. I highly doubt that Earl will say otherwise. Now what he prefers to use in his audio systems has more to do with the directivity that he has determined are a minimum requirement to meet his end goals.
LOL, the short waveguides do not load the driver like a real horn does., I did not say the coined name "waveguide" is not a horn, I'm saying it does not load the driver like a good horn does. I will not argue this fact with you. I don't care if the guy that coined the "waveguide" calls it a horn or not - if the gedlee was worried about directivety so much maybe he should use a short "waveguide" (that does not load) for directivety in the midrange and bass.
I never used the word constant directivity, I am only arguing the fact that all of these designs are waveguides. Optimization of loading of a driver is frequency and device specific. It all comes down to the final results you are attempting to accomplish. But when you say that a short waveguide is not a horn you are way off the mark. If you only want to call a traditional exponential horn a horn you can do that but it is not correct in a technical way. I agree that the loading of any conic horn is sub optimal, that is a given, they are not designed for maximum efficiency, nor are they really constant directivity in a true sense.
Oh my, I said a waveguide like the SEOS I have is not like a horn in the FACT it does not load the driver. I cannot make it any clearer for you. I do not say anything like it is not a horn and do not care what anybody calls it. The short horns like geddee uses are not my idea of a proper horn. A peoper horn will act as a transformer with the air load, the short horns are not like this they are like listening to a dome tweeter rather than a live instrument. If I wanted to listen to a dome tweeter I'd by some Mackie monitors and be done with it
Pooh,
It is a real shame that you believe what you must have read somewhere, but it is very poor information. Do you happen to know the TAD ET-703 driver. Go look that up, you will be very surprised how small a horn can be, and this has a compression driver attached. You are completely wrong in your assumption. You are saying that only an old radial or multicell horn is a horn and works as a horn does. I and Gedlee have been doing this for far to long to accept your narrow interpretation of what a horn is. Even a cone driver can follow the rules, I think I should know as I have a patent in horn design from 36 years ago. You are just repeating some misinformation, that is all.
It is a real shame that you believe what you must have read somewhere, but it is very poor information. Do you happen to know the TAD ET-703 driver. Go look that up, you will be very surprised how small a horn can be, and this has a compression driver attached. You are completely wrong in your assumption. You are saying that only an old radial or multicell horn is a horn and works as a horn does. I and Gedlee have been doing this for far to long to accept your narrow interpretation of what a horn is. Even a cone driver can follow the rules, I think I should know as I have a patent in horn design from 36 years ago. You are just repeating some misinformation, that is all.
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I'm not sure if it's your listening or reading skills but you really have a problem with one or both of them. I have NOT said what a horn is or what it is not! What I have said, please listen to what I say AGAIN, the short waveguide "horns" that are like "SEOS" or gedle DO NOT load the driver like deeper, longer, horns. I will not repeat myself again. They can't because they are too short for the bandwith they are used. GET IT?
Pooh,
That statement I can completely agree with. But I don't think that Gedlee is attempting to use the device as low as a traditional horn would go. I agree with a faster flare rate and smaller mouth they and the SEOS horns are truly high frequency devices and I wouldn't want to try and use them for low frequency reinforcement. We are on the same page with that. Typical radial horns will have a low frequency cutoff of from 300 to 800hz with a compression driver though I can't stand the sound of them that low. When we used those in pro audio applications we usually cut them at twice their rated low frequency cutoff based on 1/4 mouth size. So if you are trying to go from say a 15" bass speaker to the horn yes you would want to use a much larger horn for that. I have a midrange cone driven horn for that with a 600hz mouth size that can cover that range. And it is a loaded horn with a 25% loading factor, throat to cone sd area. Now I think we are talking the same language.
That statement I can completely agree with. But I don't think that Gedlee is attempting to use the device as low as a traditional horn would go. I agree with a faster flare rate and smaller mouth they and the SEOS horns are truly high frequency devices and I wouldn't want to try and use them for low frequency reinforcement. We are on the same page with that. Typical radial horns will have a low frequency cutoff of from 300 to 800hz with a compression driver though I can't stand the sound of them that low. When we used those in pro audio applications we usually cut them at twice their rated low frequency cutoff based on 1/4 mouth size. So if you are trying to go from say a 15" bass speaker to the horn yes you would want to use a much larger horn for that. I have a midrange cone driven horn for that with a 600hz mouth size that can cover that range. And it is a loaded horn with a 25% loading factor, throat to cone sd area. Now I think we are talking the same language.
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