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Posted by Vasyachkin on
10-16-2008
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fiogf49gjkf0d compression drivers are the way to go as far as i am concerned but obviously performance depends on the horn lens.
my beef with ET-703 is that i don't understand its horn or whatever it is. if not an explanation i would like to see maybe some polar response plots as any normal manufacturer would provide for a horn but i've seen nothing like that from pioneer.
i personally believe that the top end of the frequency spectrum is the most difficult part of the system to design so i am rather unhappy about one of the most promising supertweeters not having any useful documentation ( that i seen )
help !
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Posted by Romy the Cat on
10-16-2008
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fiogf49gjkf0d
 Vasyachkin wrote: | |
compression drivers are the way to go as far as i am concerned but obviously performance depends on the horn lens.
my beef with ET-703 is that i don't understand its horn or whatever it is. if not an explanation i would like to see maybe some polar response plots as any normal manufacturer would provide for a horn but i've seen nothing like that from pioneer.
i personally believe that the top end of the frequency spectrum is the most difficult part of the system to design so i am rather unhappy about one of the most promising supertweeters not having any useful documentation ( that i seen )
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Vasyachkin,
I did not have this driver and I do not think I ever heard it. I think there was discussion about this driver somewhere in context of Cessaro Gamma speaker that seems to use it. If TAD folks cannot help you with whatever you need than you mish consult with Cessaro folks if you speak German. Alternately you might get in touch with Duke from audiokinesis. He is TAD dealer and he worked with many of those drivers, he is not horn-type person however… Frankly speaking I am not exactly understand what you are trying to find out and why you might need the polar response from TAD. I seldom treat manufactures data with respect (for compression drivers) and if you need any more or less credible reference then why doesn’t you measure it yourself. All the you need is a $100 instilmental microphone, $25 XLR to USB adapter and a one of many measurement software that permit to calibrate sound card.
At a wider subject always was suspicion in regards to the drivers like ET-703:
http://estore.websitepros.com/1736754/Detail.bok?no=15
It might be a good driver but the horn section of it is very much compromised to begin with. If I have it I would consider substituting the original TAD horn with my own spherical horn. It might be difficult as it might be combined in the same peace with the driver’s phase plug. If it is the case then it is possible to cut it horizontally, maintaining the original phase plug and juts to glue to the cut surface a new front horn barrel. It might not be all necessarily but conceptually I do not like the slot tweeters – any rough surface or edge for HF is very bad thing. I always felt that at least the slot drivers much have teeth at the termination edge but then never care about it….
The Cat
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Posted by coops on
10-17-2008
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fiogf49gjkf0d Cessaro in fact make a spherical brass horn for the 703, drop Ralph a line ( at cessaro ) I am sure he will be answer any queries. Keith.
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Posted by Romy the Cat on
10-17-2008
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fiogf49gjkf0d | coops wrote: | | Cessaro in fact make a spherical brass horn for the 703, drop Ralph a line ( at cessaro ) I am sure he will be answer any queries. |
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Keith, if they do it then it is good for Cessaro and indicates that they are not damn. However, I never seen that they did it. Whatever I have seen the pictures the Cessaro speakers were as at the Cessaro’s web site – with default 703 driver.
http://www.puriteaudio.co.uk/
http://www.audioexotics.hk/forum.php?cat=4&show=0&id=1859
The slot tweeter are not something that shelf be blamed too much. TAD design drivers from pro application where the minuscule details of nearfiled dispersion is not something that they even consider they design outputs guidance of their drivers. I feel that to have very shallow spherical horn it much better direction.
The Cat
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Posted by coops on
10-17-2008
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fiogf49gjkf0d Romy Hi hope you are well, here's a ( rather poor  photo of the spherical horn,  , very best keith.
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Posted by Romy the Cat on
10-17-2008
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fiogf49gjkf0d If they paint/anodize the driver in black (instead of this screamy and shiny finish) and to crap the horn with zillion random texture dots then they would be almost my type of people.
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Posted by coops on
10-17-2008
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fiogf49gjkf0d Ralph spends hours polishing those tweeters!
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Posted by Romy the Cat on
10-17-2008
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fiogf49gjkf0d | coops wrote: | | Ralph spends hours polishing those tweeters! |
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Because he is a subordinate of the game that he plays to serve the interests of public consumption. Your Ralph need to worry about the moronic prejudges of public that would look at those speakers in ad’s pictures and would grow concussion that if is shiny then it shell be “High Endy”. I am sure that their marketing director when he runs his spiel justifying the high cost of Cessaro saying some like this “we spend many hours to polishing those tweeters bringing the polishing to level 15 it is huge amount of custom manual work that might be done only by the surviving singers of WWII’s Bruno Kittel Chorus”…
BTW, Keith, I am well aware about you tendency to convert any subject into a conversation about the products that you trade. Remind you that this is a there about the ET-703 driver…
The Cat
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Posted by Vasyachkin on
11-02-2008
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fiogf49gjkf0d | Romy the Cat wrote: | It might be a good driver but the horn section of it is very much compromised to begin with. If I have it I would consider substituting the original TAD horn with my own spherical horn. It might be difficult as it might be combined in the same peace with the driver’s phase plug. If it is the case then it is possible to cut it horizontally, maintaining the original phase plug and juts to glue to the cut surface a new front horn barrel. It might not be all necessarily but conceptually I do not like the slot tweeters – any rough surface or edge for HF is very bad thing. I always felt that at least the slot drivers much have teeth at the termination edge but then never care about it….
The Cat |
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that's what i was saying - the horn looks suspicious.
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Posted by Vasyachkin on
11-02-2008
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fiogf49gjkf0d | Vasyachkin wrote: | | the horn looks suspicious. |
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my issue with it, though, is not the discontinuity in the curvature but rather overall dimensions.
it looks too wide to be a slot. this is a product that is supposed to work at 20+ khz and the slot is like an inch wide - which is nothing like a line source at 20 khz.
if you assume that this thing is intended to operate between 10 khz and 20 khz, which i think is a reasonable assumption, then it actually looks more like a normal horn. i mean take a regular horn designed to work from 1khz and up and make it 10 times smaller and that's more or less what it would look like.
except if that was the case then it should be used sideways, not vertically like Cessaro uses it. this really confuses me.
and as far as modifying it with a spherical horn i have the following issue with that: i don't believe in modifying products that weren't engineered right in the first place. i don't believe in fixing somebody else's mistakes. things should be done right in the first place imho.
there is always the possibility that Cessaro don't know what they're doing and simply copied the way it looks on Pioneer's page ? and that is the reason for the vertical orientation ? but that idea seems far-fetched even by my own standards 
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Posted by Romy the Cat on
11-02-2008
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fiogf49gjkf0d Vasyachkin,
I have different view about “modifying products” as any product is always implying something very generic but I have my own needs. Probably not “modifying” but adopting would be better but it is not the subject in here.
If you read my site, the evolution of my tweeters, then you might see that I stepped away from the idea of horn tweeters. A horn is equalization devise that boost lower knee. If people need to spread a tweeter in MF then it is OK but in my case my tweeter sits at 12.5K and I do not need any gain at LF – this would only make my crossover sharper. So, ET-703 has a good motor, phase plug, diaphragm and suspension then a better horn for it a mast. What kind horn? It would depends from where and how it will be used. It looks like Cessaro made 6K-7K hors. If I use it for my Macondo then I would make it twice shallower. However, this type of driver would not work in my case as I need to control horizontal dispersion….
The Cat
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Posted by Vasyachkin on
11-02-2008
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fiogf49gjkf0d | Romy the Cat wrote: | | I stepped away from the idea of horn tweeters. A horn is equalization devise that boost lower knee. If people need to spread a tweeter in MF then it is OK but in my case my tweeter sits at 12.5K and I do not need any gain at LF |
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i don't see horns as equalization devices. i don't even believe in flat response as a reasonable design goal for a speaker. i believe equalization should be done electronically.
to me horns are well, what they actually are - acoustical impedance transformers. means to boost efficiency.
i believe horns are needed at lowest and highest frequencies. at lowest because there isn't enough power (in your household wiring) to hit required SPLs without them and at highest because delicate tweeter voice coils can't hit high enough SPL without them.
ability to shape dispersion pattern is an added benefit. i would say horns are 70% about efficiency gain and 30% about directivity control.
and if horns, in their majority, roll off in the highest octave i do not believe that it is their inherent feature but rather details of particular implementation. many people can't hear past 15 khz and since horns are mainly developed in pro audio and pro audio is a practical business they probably just don't care about that last octave just like they don't care about the first one.
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Posted by Romy the Cat on
11-02-2008
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fiogf49gjkf0d | Vasyachkin wrote: | | i don't see horns as equalization devices. i don't even believe in flat response as a reasonable design goal for a speaker. i believe equalization should be done electronically. to me horns are well, what they actually are - acoustical impedance transformers. means to boost efficiency. i believe horns are needed at lowest and highest frequencies. at lowest because there isn't enough power (in your household wiring) to hit required SPLs without them and at highest because delicate tweeter voice coils can't hit high enough SPL without them. ability to shape dispersion pattern is an added benefit. i would say horns are 70% about efficiency gain and 30% about directivity control. |
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A big mistake on all accounts but you are in your constitutional right to believe in what you wish. The acoustical impedance transformation gives no explanation to the practical applied sound that you might get from a horn. I do not know what you actually do with horn but from what you said it looks like you just chew over banal book theory but so far you were not able to made horn-loading to sound in any specific objective way.
Rgs, The CaT
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Posted by Vasyachkin on
11-03-2008
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fiogf49gjkf0d | Romy the Cat wrote: | | acoustical impedance transformation gives no explanation to the practical applied sound that you might get from a horn. |
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i am sure there must be differences between theory and practice. i would like to know what you think are the most important differences. what effects do you observe in practice that you don't think are adequately explained by theory? i want to see if can figure out what can be causing some of those effects.
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