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Multi-Way Conventional loudspeakers with crossovers

The Advantages of Floor Coupled Up-Firing Speakers
The Advantages of Floor Coupled Up-Firing Speakers
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Old 1st April 2010, 09:08 AM   #1211
Rudolf is offline Rudolf  Germany
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Quote:
Originally Posted by graaf View Post
as to Peter Walker's FRED with concentric delay lines it was intentionally designed to simulate point source as much as possible with panel ESL speaker and in such a way to overcome very directional problems of earlier simple panel ESL-57
Above must read "as to Peter Walker's FRED with concentric delay lines it was intentionally designed to simulate a two-point source as much as possible with panel ESL speaker and in such a way to overcome problems with directivity changing along frequency of earlier simple panel ESL-57"

Directivity alone doesn't help much if it is not kept constant with changing frequency. I believe that is the central message those "theoretical requirements of sufficiently high and constant directivity" are trying to tell you.

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Old 1st April 2010, 09:17 AM   #1212
LineArray is offline LineArray  Germany
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Quote:
Originally Posted by Rudolf View Post
...
Directivity alone doesn't help much if it is not kept constant with changing frequency.
...
In that point there seems to be much agreement ...
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Old 1st April 2010, 10:10 AM   #1213
graaf is offline graaf  Poland
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Quote:
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In that point there seems to be much agreement ...
yes indeed, I can see no controversy on that point, horizontal directivity should be constant in any case, and vertical dispersion shoul be narrow unless something else is done WRT interaction of speakers with floor and ceiling

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Originally Posted by LineArray View Post
The Beveridge is a line source which has very narrow vertical dispersion.

Neither Beveridge has 180 degrees horizontal dispersion
narrow line source means also very wide horizontal dispersion
in comparison to "common multiway designs, which may serve as a reference to the common listener" as You have rightly observed, and with recommended placement in the room it is practically as if 180°, real 180° would make no difference
in His patent HB claimed at least 150°:
Patent US3980829

only coincident flooders can possibly be better in this respect with horizontal dispersion being perfectly constant and 360°

best,
graaf
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Old 1st April 2010, 10:34 AM   #1214
LineArray is offline LineArray  Germany
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Somehow i anticipated, that the ceiling flooder would come
into play ...
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Old 1st April 2010, 11:02 AM   #1215
graaf is offline graaf  Poland
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Quote:
Originally Posted by LineArray View Post
Somehow i anticipated, that the ceiling flooder would come
into play ...
and? what is the point?

don't You know that it is the main topic of the thread?
so everyone can expect it to come into play all the time

this is the topic of this thread
this and other unusual setups

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Originally Posted by graaf View Post
What do You think? Any suggestions? Ideas? Your own unusual setups?
no need to anticipate, You can simply expect the topic of thread to emerge in it at least from time to time, wouldn't You agree?

best,
graaf
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Old 1st April 2010, 11:07 AM   #1216
poptart is offline poptart  Canada
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I love that logan's run got in here, thanks for that.

Toole's book is absolutely worth reading for anyone who's participating in this hobby or this site. You might agree or disagree with points in it, I know Earl Geddes disagrees with some of Toole's conclusions, but at least he knows what he's disagreeing with and the data is pretty hard to argue. It's a data and research based book and that's pretty rare in this hobby. Did I read you saying Markus that it doesn't address omnis? I don't know about that, it argues for equal or at least smoothly changing on and off axis response. Sounds like an omni qualifies. A lot of things could, it's not the means we're after it's the end. It's clear from the book that some kind of "shaded" line arrays were Tooles current thought-flavor of choice but that doesn't mean much. He's after a result, not the one true way. Wide directivity designs can achieve that, narrow directivity/waveguide speakers can too. In the book he didn't go so far as to stake out one camp or other, but we know from his work he actually favours wide directivity.

ps. Markus, vlc plays flac flawlessly on my machine. Not sure what issues you're referring to. It can't convert other files to flac etc but that's not the point of the program, just a player.

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Old 1st April 2010, 11:08 AM   #1217
Rudolf is offline Rudolf  Germany
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Quote:
Originally Posted by graaf View Post
yes indeed, I can see no controversy on that point, horizontal directivity should be constant in any case, and vertical dispersion should be narrow unless something else is done WRT interaction of speakers with floor and ceiling
We really need to use precise definitions - otherwise we are talking about different things - resulting in the usual misunderstanding.
I don´t know of any loudspeaker concept were directivity changes with angle along the vertical or horizontal axis. What does change is the sound pressure level as a function of the directivity index. So did you mean "horizontal and vertical SPL level should be constant in any case"? That would mean a directivity factor of 1 or directivity index of 0 dB.

Same for "and vertical dispersion should be narrow unless something else is done WRT interaction of speakers with floor and ceiling". A narrow vertical dispersion (high vertical directivity) would mean maximal excitation of floor and ceiling reflections compared to horizontal, yes? Is this a recommendation for your "flooder" only or meant "in general"?
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Old 1st April 2010, 11:28 AM   #1218
graaf is offline graaf  Poland
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Quote:
Originally Posted by Rudolf View Post
I don´t know of any loudspeaker concept were directivity changes with angle along the vertical or horizontal axis.
?? I am not sure what You mean

Quote:
Originally Posted by Rudolf View Post
So did you mean "horizontal and vertical SPL level should be constant in any case"?
absolutely not
what does constant directivity mean to You?

because for me Dr Geddes speaker is an example of constant directivity speaker and also Beveridge line source ESL is

Quote:
Originally Posted by Rudolf View Post
A narrow vertical dispersion (high vertical directivity) would mean maximal excitation of floor and ceiling reflections compared to horizontal, yes?
of course not - the opposite

You are kidding, right? But what's the point?
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Old 1st April 2010, 11:36 AM   #1219
graaf is offline graaf  Poland
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Quote:
Originally Posted by poptart View Post
Sounds like an omni qualifies
It sounds like this to me as well. And it is nothing new, we can find this requirements in earlier Toole's publications
Toole also asserts that horizontal early reflections are not detrimental to quality of sound reproduction.

and I really agree with Toole's conclusions, and I know His conclusions, no need reading through hundreds of pages to know conclusions

Yet Markus has been beating me precisely with this book for some 500 posts now. I really don't know why

it cannot work! it is not right! go read the book! and so on and so on...

best regards,
graaf
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Last edited by graaf; 1st April 2010 at 11:50 AM.
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Old 1st April 2010, 11:46 AM   #1220
graaf is offline graaf  Poland
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parts of my first post, for clarification of some things:

Quote:
Originally Posted by graaf View Post
(...)
I have very unusual loudspeakers which I have built some time ago with those room-speaker interface things in mind. These are very short omnidirectional loudspeakers. They are just 20 cm high and have 8 inches wide range driver on top and firing upwards.
The loudspeakers are to work on the floor – the driver is only 20 cm above the floor – and against the wall.
(...)
my first and main aim was to eliminate the detrimental effect of early floor and ceiling reflections without resorting to unavailable true linesource (like Beveridge)
(...)
But frankly speaking I wasn’t thinking a lot and I think now that I really didn’t know what I was doing and still I don’t – I have no technical background – and it was and it is all mostly intuitive.
(...)
But the outcome appeared to be quite satisfying.
(...)
I am considering positioning the speakers against the opposite longer walls (scheme attached). Stereo basis would be 330 cm. The listener is to be located 200 cm from stereo basis, 250 cm from both speakers
(...)
To my not very big surprise the resulting set up happens to be very much like Beveridge positioning of his line source electrostatics.
(...)
What do You think? Any suggestions? Ideas? Your own unusual setups?
I claimed no right of inventing the wheel, nor any extraordinary expertise (quite the opposite actually)
I haven't attacked any other design nor anyone personally
I asked for help.

What did I get here in response during the last two years? Mainly beating

what do You think? - We think this is a distaster!
any suggestions? - it cannot work!
any ideas? - go read the books!

and all these mainly from certain manufacturer and a certain open admirer of certain commercial product
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