markus76 said:
Uniform? Same as constant?
I don't know any box speakers with monopole bass and high directivity tweeter that has constant directivity.
Are you able to provide any input to the original question
http://www.diyaudio.com/forums/showthread.php?postid=1633080#post1633080
or just asking more questions about question.
You propose uniform polar pattern, at what freq range you see it important and _why_?
- Elias
markus76 said:
Please feel free to correct me if I'm wrong, but..
Is this thread about measurements or perception? (..specifically the subjective responses of others with regard to loudspeakers.)
Is lower distortion necessarily a perceptual improvement? If so:
What type?
At what level?
At what freq.?
With what "material"?
..also,
What level of output is required and at what freq.?
Are lower power requirements necessary to achieve better sound?
Is an extended freq. range neccesary? If so - what range?
(They are all good questions to Loudspeaker Perception, but they *may* not be relevant with any particular design involving a dipole. First determine what people are finding better with a dipole, THEN determine if it can meet the requirements of these questions for any particular design. THEN *if* a particular design using a dipole fails one or more of the above, determine if that harm is, or is not, out-weighed by the benefit of dipole operation.)
Is lower cost going to improve audible perception?
Is easier implementation going to improve audible perception?
(These last two questions have nothing to do with this thread.)
And some other non-scientific claim from me. I have always preferred horn loaded bass/midbass to BR or closed box. Dipole bass is somehow similar to horns, but at much lower sensitivity. I wonder if it has something to do with the midbass directivity...This is from what my ears prefered long before I knew this forum and this thread...kind of psycho-acoustical
markus76 said:
Please do not get me wrong - I try to explain, what I mean. Common practice in speaker design is to have smooth directivity transition around the crossover point. You do the same with bipole woofer when crossing to a monopole tweeter. I am trying to say is that it really does not matter, if you cross a dipole or monopole woofer to a tweeter. The only difference is below certain frequency, where the woofer behaves as a dipole. Above it, regardless of the configuration, both start to "beam". Below it, you have constant directivity with dipoles and cardioid changing to spherical with monopole. So my point is that if you used the Nathan waveguide with a dipole instead of monopole, the directivity would be more constant towards the lows.
That means, that you can have "a uniform polar pattern with no breaks in directivity" using monopole or dipole woofer. I guess we are talking about woofer operation to control directivity at low frequencies as well. Not about full range dipoles - which is definitely not "reasonable or practical".
In fact, I would like to hear the speakers of Mr. Geddes with both midbass (monopole/dipole) options in a blind test.
And as a matter of fact, no tweeter is really a monopole, which is defined as a point sound source with spherical directivity - there is no tweeter like that except those plasma/bladder exotic things.
markus76 said:Scott, you really want me to summarize the results of research of the last decades? Even if I could I wouldn't - I would write a book or 2 and sell it to you
I can "tell" you what most of the "answers" are..
FOR ANY GIVEN AUTHOR.
What I can't give you is any firm consensus (across a wide range) of *theorists* and listeners.
If you can, then by all means do so - as they actually pertain to this thread's topic.
(.."write a book or 2"..makes me want to smack you over the head with a full Klippel suite.
)
Ah, the emotional aspects of dipoles versus monopoles! Way too "subjective" for me.
Scott
"Is this thread about measurements or perception? (..specifically the subjective responses of others with regard to loudspeakers.)"
I would not agree that this *was* the topic, but it seems to be now. I originally proposed this to thread to talk about the scientific aspects of perception and loudspeakers in small rooms. To me this is an completely objective domain where subjective responses have been defined and correlated through scientific studies. Markus and I have tried to show these scientific results, but we keep getting met with "well it sounds good to me". OK, thats fine, but its not scientific and it's not what I am interested in.
Scott
"Is this thread about measurements or perception? (..specifically the subjective responses of others with regard to loudspeakers.)"
I would not agree that this *was* the topic, but it seems to be now. I originally proposed this to thread to talk about the scientific aspects of perception and loudspeakers in small rooms. To me this is an completely objective domain where subjective responses have been defined and correlated through scientific studies. Markus and I have tried to show these scientific results, but we keep getting met with "well it sounds good to me". OK, thats fine, but its not scientific and it's not what I am interested in.
I liked my dipol sub - now I have this very expensive Gedlee speaker that I have to love
An externally hosted image should be here but it was not working when we last tested it.
gedlee said:
That's an interesting limitation for the thread's topic.
If that was your intended purpose for proposing the thread then why didn't you state it at the beginning? Or perhaps upon realizing that others had a more reasonable interpretation (..just on the basis of the title's interpretation), why not create a split-off thread for that purpose? I mean, here we are 23 pages deep.
As far as *this* thread is concerned - its been many things. Starting with "image" localization, effects of OPEN BAFFLES, "spaciousness", 3D "imaging", and the list goes on.
Academic sources? ..that's in here - and from several participants on a range of topics. (..It has not just been you and Markus.)
Nor have you NOT participated in subjective comments. You've made your own subjective claims, and even asked that we view the reviews in your advertising. BOTH of which are perfectly reasonable to the discussion - as it has been from the start, AND as any reasonable person would perceive by reading the thread's title.
Then you claim that (you and Markus):
"..tried to show these scientific results, but we keep getting met with "well it sounds good to me"".
You have, several of us have - but the "well it sounds good to me", is almost certainly valid to the person making the claim, and again - this is something you have done yourself. (..and most of the time its quite a bit more specific than "well it sounds good to me".) It *is* a forum, that's not just an acceptable type of response - its often "THE" response. You may have problems with it, but you've done pretty well so far.
One last note (something I've discussed with you before):
Science, or even "scientific" - is not limited to just a peer "reviewed" paper on a particular subject.
Science is all about discovery, not simply knowledge as it is currently known - but the *pursuit* of knowledge.
Scientific, or use of the Scientific Method, constrains this search through use of reproducible results.
As far as I know - NO ONE has made a claim that they haven't had reproducible results with on those certain types of: "sounds good to me" claims. Moreover many of these claims can and have been tested by others. Additionally there have been several suggestions (tests) made for just this purpose - I know I've made at least one, so has Markus, so has Elias. (..tests that for the most part can practically be performed.)
Of course then we get into the "control" of the testing - is it good enough for peer "review"? Probably not. But then you already knew the answer to that. Given the setting (forum) and most of the potential participants - that is the reasonable answer.
Science is occurring, right here, right now. It may be a little "soft", but at least there is a *pursuit* rather than simply a restatement of the "known". If you are more interested in the latter, SL has the solution: a "faq" listing that he can link to anytime he thinks its pertinent to a topic. It works, and overall it takes up a LOT less time. (..the forum has a Wiki function that would be perfect for it.) Oh, and don't forget the option for another thread to your specifications - it *is* still an option.
This could be an interesting paper:
http://www.aes.org/e-lib/browse.cfm?elib=11078
I do not want to spend 20 USD, as half of the papers is worthless - and I do not want to take the risk of getting an useless paper for 20 USD.
http://www.aes.org/e-lib/browse.cfm?elib=11078
I do not want to spend 20 USD, as half of the papers is worthless - and I do not want to take the risk of getting an useless paper for 20 USD.
markus76 said:I liked my dipol sub - now I have this very expensive Gedlee speaker that I have to love
An externally hosted image should be here but it was not working when we last tested it.
He!! I like your dipole sub and your Gedlee speaker setup.
pelanj said:
Yeah, that's a *BIG* problem. I don't even want to spend 5 US for it. Its not that I'm cheap (though sometimes I am), but rather the question of: are you getting exactly what you want? ..or is it something you aren't specifically interested in (..or relies on multiple sources, none of which you have access to unless you get out your credit card).
If I was professionally involved, I'd likely take the risk. But for most of us this is a freek'in hobby.
(..I can just imagine some poor sod trying to explain to his/her spouse: "no we can't go out to dinner tonight, but you can read these papers I purchased for my hobby." ..and then of course the ensuing vicious and brutal attack.
)
Hello,
No need for anyone to get emotional. Instead what we need is that someone provides objective psychoacoustic reasons why monopole should be used in the freq range 20Hz-1kHz instead of a directional source. Because I think it is very important thing to find out which kind of source provides maximum delivery of psychoacoustic benefits in typical reverberant living rooms to the listener if and when we are on the quest in finding the ultimate.
So far either Earl or Markus or no one else have provided none of such reasons.
- Elias
gedlee said:
No need for anyone to get emotional. Instead what we need is that someone provides objective psychoacoustic reasons why monopole should be used in the freq range 20Hz-1kHz instead of a directional source. Because I think it is very important thing to find out which kind of source provides maximum delivery of psychoacoustic benefits in typical reverberant living rooms to the listener if and when we are on the quest in finding the ultimate.
So far either Earl or Markus or no one else have provided none of such reasons.
- Elias
pelanj, "The frequency response using a two-dimensional room model is computed, and a perceptual model is used to estimate the importance of the room response effects in coloring the reproduced sound." (from Dipole Loudspeaker Response in Listening Rooms by Kates, James M.)
No real world data. Pretty useless. I could have access to the paper but it only restates what we already know.
No real world data. Pretty useless. I could have access to the paper but it only restates what we already know.
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