You are absolutely right. In my previous posts i was talking about directivity.
Sometimes express yourself in foreign language is complicated. Can even be in my native one so...
So to clarify my previous statement: imaging capacity (stereo rendering of a recorded or imaginary 'musical scene') of a loudspeaker pair is not (totally) linked to the directivity behavior.
Wether wide (omnipole), narrow (dipole) or anything in between directivity wise, you can achieve very good imaging. But each case in a different kind of presentation and with it's own set of issues and strength in the way they interface with the room they are located in ( and which form a system with a singular behavior which in my view needs to be taken and treated as a whole).
Hence the trend to use waveguide on tweeter to match directivity behavior since mid 90's ( Genelec range of studio monitors comes to mind from 1031 to 1037/38).
I'm all with you about smooth directivity transition and power curve ( my three ways are poor in this domain and the reason i tried to 'improve' them and now heading to something different).
Works of Earl Geddes are interesting to read about that.
Well as already stated in there, in some way yes a crossover design could ruin the perceved depth as it could 'corrupt' the cues about the recorded 'scene' embeded in the original signal.
I think too that crossover points ( and type )may be relevant but without a concrete design to speak of it might be too vast to approach here, but let's say that some area might be less harmfull than others to put a xover in and some 'recents' trends are based on that ( the 'econowave'/ 'constant directivity' waveguide school of thoughts) .
It seems you discovered that room placement and interface to room were culprit and like others this is what i would have thoughts too.
Here is something i do which help me to assess this kind of very subjective interpretation: when listening i close my eyes.
It may not be instantly but soon you'll hear the 'scene' more easily and if there is difference. At least it works for me. Our brain is highly influenced by our view which take up to 90% of your brain capacity constantly.
Relieving it from this task it is easier to focus on the 'scene' in your brain.
About the room by itself and reflections. As Allen, Ben or ScottJoplin (and others says) it is really a matter of preference about presentation and what you listen to (not the kind of music but what interest you in the presentation of the signal).
Some will like the spaciousness some early reflection will bring, some will dislike it and consider them as 'distortion'.
Some want to 'be there' other wants 'they are here ( in your room)'. Some wants to be in between...
As Allen stated i think there is good and bad one (reflections). We most of the time focus on the lateral ones but by far the worst are from floor and ceilling ( the smaller dimension of a room).
The thing being to know what you like and why you made decission about design.
In the end there is no definitive answer or one size fit all about that as it is a preference thing.
https://www.linkwitzlab.com/Fitz/considerations.htm said:11 June 2013 - #5 - &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
Fitz: Already had a drawing. Here it is.
I used inch dimensions because when I work with wood everything is measured in inch and feet locally and I have gotten used to that when it comes to loudspeaker design.
SL: That was fast. I will analyze your design for its acoustic and electro-acoustic properties.
But first I need to tell you about my acoustic measuring stick.
12 June 2016 - #6 - &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
SL: I just realized that I will probably not get to this analysis for quite a while, because I need to explain not just my acoustic measuring stick but also a number of acoustic concepts for the analysis to make sense, like:
Point source, dependent source, free field, wave guide, cavity, lumped source, distributed source, compliance, mass, damping, reflection, diffraction, scattering, etc.. That will take some time.
You obviously have some expectations for the performance of Design #3 as compared to the LXmini, but have you considered what might be problematic in your design?
*** If others are reading our conversation they might want to start a discussion about Design #3 on the OPLUG forum. Later you can read here what I had to say and compare notes. Start by printing out Design #3 and mark it up. ***
15 June 2016 - #7 - &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
SL: I looked at your drawing and marked it up to see for myself which acoustic properties we need to talk about. I see from your drawing that you have made a number of good decisions, but that may not be obvious to some of the readers here. So I need to explain those in addition to where the design could be problematic. I only marked up the acoustic areas of concern. In addition we need to look at the electro-dynamic properties of the drivers to ***** their suitability for your loudness and distortion wishes and requirements.
Fitz: I see a lot of red ink.
SL: Like I said, I have a lot to explain.
But I really want to do this because I perceive a major need for better understanding of acoustics. I also want to do this with an absolute minimum of math. I want to convey a more intuitive understanding of acoustic waves, how they are excited, propagate and interact with their environment and with living creatures, like us.
Fitz: That seems like a worthwhile project. I would love to learn more myself.
SL: OK, Fitz, let's do it.
Cognitive dissonance?
Would it be a sensible thing to capture imaging problems in a graph like this:
Where qualities like "width, depth, spaciousness and pin-point accuracy etc" can be described by the parameters that distort or create them?
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Could you explain your thoughts Celef, i don't follow you ( especially your two last sentence)?
Hmm my last post is missing a lot of text.
I should have know it had to go wrong when the page had to reload while posting.
Forgive me for keeping it short.
After Celef's quote there was supposed to be a question:
"Would it matter if the tweeter was omnipole or dipole"
There is no relation to the story of Linkwitz other than that the dayton planars reminded me of open back tweeters, and the Fitz story. My question was how it could be possible that there are so many opinions regarding building a speaker a certain way. To be more precise: is it possible that what one thinks of as real sounding, is regarded differently by another?
I hope this post now saves correctly because I don't want to type it again
I should have know it had to go wrong when the page had to reload while posting.
Forgive me for keeping it short.
After Celef's quote there was supposed to be a question:
"Would it matter if the tweeter was omnipole or dipole"
There is no relation to the story of Linkwitz other than that the dayton planars reminded me of open back tweeters, and the Fitz story. My question was how it could be possible that there are so many opinions regarding building a speaker a certain way. To be more precise: is it possible that what one thinks of as real sounding, is regarded differently by another?
I hope this post now saves correctly because I don't want to type it again
Hi,
as it turns out most of the topics in 2019 are already discussed or answered years ago Here is a text by Tom Danley on hearing depth from a recording: "The phase coherence of harmonics in the vocal formant range, ~630Hz to 4000Hz"
Click saver: Crossovers are partially involved, other aspects of speaker design affect as well. Main thing is to eliminate speaker from revealing it self by reducing diffracted / interfering sounds as much as possible.
Oversimplified conclusion by me:
- When speaker reveals its position to ear/brain, it is difficult to hear to depth information in the recording and instead brain tunes to the speaker position in the room.
- When speaker doesn't reveal its position brain adjusts to the depth information baked into the recording.
Any thoughts?
as it turns out most of the topics in 2019 are already discussed or answered years ago
Here is a text by Tom Danley on hearing depth from a recording: "The phase coherence of harmonics in the vocal formant range, ~630Hz to 4000Hz"Click saver: Crossovers are partially involved, other aspects of speaker design affect as well. Main thing is to eliminate speaker from revealing it self by reducing diffracted / interfering sounds as much as possible.
Oversimplified conclusion by me:
- When speaker reveals its position to ear/brain, it is difficult to hear to depth information in the recording and instead brain tunes to the speaker position in the room.
- When speaker doesn't reveal its position brain adjusts to the depth information baked into the recording.
Any thoughts?
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///Oversimplified conclusion by me:
- When speaker reveals its position to ear/brain, it is difficult to hear to depth information in the recording and instead brain tunes to the speaker position in the room.
- When speaker doesn't reveal its position brain adjusts to the depth information baked into the recording.
Any thoughts?
Thanks for finding the Danley post. Quite interesting but something of a mix of fact, Euclidean simplification, and opinion.
Your summary seems about right to me and fair to say. But the question is the "reveal" as poker players say. But I doubt it is some Euclidean interference pattern that you hear with your ears (as opposed to Danley "hearing" it with his eyes on a plot). The more the speakers reveal themselves (for example, by any difference in FR, noises, room effects, etc), the more you are seeing the paint on canvas, not the barnyard.
Danley is explicit (if you read carefully) that stereo speakers give you bearing localization but depth is based on cues in the recording. So tmuikku would be more correct to say, as Danley roughly does, cues to depth in the recording but that may be of the soft and vague sort, not something that comes from geometrical information in the sound stream or any hocus-pokus about crossovers.
B.
Yeah recordings don't necessary have depth cues. I think it is matter of preference who likes what and what kind of recordings they listen to, taste.
Krivium pretty much nails it in post #121 how I've understood the issue and the Danley post is kind of the same but explained through an example. Crossovers among other things (diffraction) might "ruin" depth from recordings by giving brain a hard time interpreting whats the sound. A good loudspeaker is probably easier to ones brain than the other and brains differ.
So yeah no hocus pocus needed, just understanding what the brain likes and how to achieve that, what are the compromises to take on a design that lead there Just my opinion currently. I have been trying crossovers (and other things) with my prototype recently, trying to make the speaker invisible. Not quite there yet and thus this is an interesting topic. My hunch is it is not the crossover per se but the drivers + crossover, aka whole system
Krivium pretty much nails it in post #121 how I've understood the issue and the Danley post is kind of the same but explained through an example. Crossovers among other things (diffraction) might "ruin" depth from recordings by giving brain a hard time interpreting whats the sound. A good loudspeaker is probably easier to ones brain than the other and brains differ.
So yeah no hocus pocus needed, just understanding what the brain likes and how to achieve that, what are the compromises to take on a design that lead there
Just my opinion currently. I have been trying crossovers (and other things) with my prototype recently, trying to make the speaker invisible. Not quite there yet and thus this is an interesting topic. My hunch is it is not the crossover per se but the drivers + crossover, aka whole system
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to me coaxial drivers are easier to detect in the soundfield, close your eyes and you can with high accuracy pinpoint where the coaxial drivers are located. with seperated drivers the location is much more diffused and thus harder to pinpoint
Not my experience at all (neither the one commonly accepted in pro world) but this is not important.
I conclude we just don't listen to the same things and are not interested in the same kind of presentation.
Have you listened to the video linked in T.Danley's message quoted by Tmuikku ( Thank you Tmuikku! comparison between Q7 and Sm80)? Pretty representative to what i experience between coax and threeway at home?
The difference comes from center to center distance mainly other parameters being close enough and as i experience same thing at home with 'just' coax ( not MEH).
Ben don't underestimate live sound engineer or people involved inyo this field.
It is an highly competitive field with particular needs and a lot of very competent people.
Even harder if you are a manufacturer of gear.
Issues faced are different from audiophile concern ( you don't have to fight wind, different temperature layer at sunset, rooms with dimension so big that typical reflection are in the range of a slapback delay,etc, etc,...).
Tools developed by Danley are trusted and effective in real life. Even if you are doubtfull.
yes we might listening to different things. i do find coaxial drivers to work better then seperated drivers in some ways, i think the sound is less "phasey" when i move my head outside the sweet spot with coaxials, this is not so much of an issue when listening to music, but when listening to dialogues in movies throu stereo speakers this can be very annoying, i am not sure why this is?
i have not yet read it
what do you all think about ted jordans trick to get a stable stereo image, using short line arrays as to combat proximity effect and use heavy toe in for the speakers
http://www.ejjordan.co.uk/PDFs/HFN 1979.04 Jordan Hexagonal-screen.pdf
The 'phasey' thing is really what i dislike about 'conventional' multiway. It comes from my former job as sound engineer: when you have to move to perform eq on a large desk and sound change it is really disturbing to me. To the point i got fatigue as my brain has to constantly check for the changes and how to counteract them to make valid choice of eq.
I think i've got what happen with phantom image and dialogue: in fact the phantom image is effectevely very good on a sweet spot ( which is not small in my room despite the 'small' coax i use (8") ) and you have higher contrast with place where issues arise. This is the 'contrast' thing which jump out in my opinion.
The same kind of things is reported in this for example: Controlled Image Design: The management of stereophonic image quality - BBC R&D
where the difference between sweetspot and average random listening spot is considered to be high because of the Reflection Free Zone created in the design.
I suppose you might here ear floor bounce issue much clearly too ( and not the lowest one but the higher frequency one), at least this is what it seems to me in my ( highly untreated!) room atm.
About Danley's post keep an hand on a headphone pair to listen to the comparison. This is very interesting and we could use it as an example and analyze a bit what happens. Well what i think happen. There is some criticism about the comparison to be made though.
Line array, well not simple. First thank you for the link i briefly read it but'll do it more seriously later.
I know what i think of most ( big) PA line array i've heard.
This is not dissimilar to what is in here (sorry about obscession about DSL but i've got this article open atm which sum it up well for me):
centerline-av-1 | Danley Sound Labs J1 Review
For smaller one i don't know. Some have great results using the principle ( Wesayso 's 'two towers' is a brilliant example but every bit of details have been thoughts of in his build, and he got impressive data to back up his findings, and strong background analysis to boot on: he knows where he is going).
I've not heard system like that so can't speak of it in a small room but there is no reason it would not work well, with it's own presentation and set of issues.
I've got an article you could find interesting about all this from Dave Smith ( former Jbl designer, Krell designer and Mc Intosh designer... he developed many things including 'point source' kind for Krell, horn loaded monitors for Jbl (4430/4435) and array too for McIntosh, i will link it tonight.).
Edit: here it is:
[Interview] David Smith [English]
[Interview] David Smith [English]
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I have listen and i really do not know what to listen for, the first song sounded best and more direct throu sm80, with the second song the sm80 sounded too ”shouty” and the last i really could not tell. This is a bit of a problem i think, improve some parameters and others gets worse. Sometimes i almost think it sounds better to have two slightly different loudspeakers for left and right channel so they mask each others faults, sounds more like a live event to me.
May i ask which coaxs you are using?
May i ask which coaxs you are using?
Hi Celef,
Atm i have Tannoy System 800 passive driven by Amcron/Crown amp ( From D75 to D150 following my mood) and Dac are from my Dolby Lake processor ( straight chanel no treatment used except input volume control, it is initially dedicated to the threeways but it is better for fair comparison to have same 'front end ' for both) digital source being a pc with Rme aes card to Lake. For analog source ( yes i still have some) i use Lake's AD converters.
I use them at apex of 3 meter side triangle ( listening position being the third apex) height being ear height (950cm).
They are not supposed to be used this way and their intended use being nearfield there is a little recessed high freq as they are used atm in my room.
There is a bit of toe in something around 15* off axis ( they are tilted at 45* rather than 60* and spray closest side wall of their position).
I've played a lot with toe in lately and discovered interesting thing in my room... but it is a bit off .
Sweet spot is around 1m/1,5m wide before there is issues with phantom image (shift to closest loudspeaker).
I must go to work atm so will talk about the comparison later tonight but i ear almost same thing as you so you know what to listen in my view ...the thing being to understand what happen!.
Atm i have Tannoy System 800 passive driven by Amcron/Crown amp ( From D75 to D150 following my mood) and Dac are from my Dolby Lake processor ( straight chanel no treatment used except input volume control, it is initially dedicated to the threeways but it is better for fair comparison to have same 'front end ' for both) digital source being a pc with Rme aes card to Lake. For analog source ( yes i still have some) i use Lake's AD converters.
I use them at apex of 3 meter side triangle ( listening position being the third apex) height being ear height (950cm).
They are not supposed to be used this way and their intended use being nearfield there is a little recessed high freq as they are used atm in my room.
There is a bit of toe in something around 15* off axis ( they are tilted at 45* rather than 60* and spray closest side wall of their position).
I've played a lot with toe in lately and discovered interesting thing in my room... but it is a bit off .
Sweet spot is around 1m/1,5m wide before there is issues with phantom image (shift to closest loudspeaker).
I must go to work atm so will talk about the comparison later tonight but i ear almost same thing as you so you know what to listen in my view ...the thing being to understand what happen!
.
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