Joachim,
In my book that would be a soffit-mounted Speaker, in other words one in an infinite baffle or alternatively a speaker fitted with a suitable waveguide or alternative means of directivity control to avoid any sound "bending around" (diffracting around) the baffle/driver mounting plane.
What is shown at the beginning of the thread is more like a 100% diffraction loudspeaker, as the sound is allowed to diffract (bend) around the bare drivers maximally, although this is not enough for a true omni radiation.
It seems to parallel the B&W Nautilus principles.
The merits of such a solution will depend heavily on the room conditions and personal preferences. I tend to be on the other side of that particular fence in the "minimum diffraction" camp, instead of in the "maximum diffraction" camp, but "horses for courses" and "different strokes for different blokes" and all that...
Ciao T
In my book that would be a soffit-mounted Speaker, in other words one in an infinite baffle or alternatively a speaker fitted with a suitable waveguide or alternative means of directivity control to avoid any sound "bending around" (diffracting around) the baffle/driver mounting plane.
What is shown at the beginning of the thread is more like a 100% diffraction loudspeaker, as the sound is allowed to diffract (bend) around the bare drivers maximally, although this is not enough for a true omni radiation.
It seems to parallel the B&W Nautilus principles.
The merits of such a solution will depend heavily on the room conditions and personal preferences. I tend to be on the other side of that particular fence in the "minimum diffraction" camp, instead of in the "maximum diffraction" camp, but "horses for courses" and "different strokes for different blokes" and all that...
Ciao T
Thorsten, i have heard your speaker. You have not heard the one i am designing here.
When my speaker is ready, please visit me and bring yours. What i claim is, that a speaker designed like a ZDL i defined " disappears" when listened to in the nearfileld.
We can then discuss at length if yours " disappears " better. I whould call it "maximun dispersion" and not " maximum diffraction" anyway because, as i have already shown, a small enough tweater in "free air" does not suffer much from defraction.
When my speaker is ready, please visit me and bring yours. What i claim is, that a speaker designed like a ZDL i defined " disappears" when listened to in the nearfileld.
We can then discuss at length if yours " disappears " better. I whould call it "maximun dispersion" and not " maximum diffraction" anyway because, as i have already shown, a small enough tweater in "free air" does not suffer much from defraction.
Hello Gents,Here is a question for the driver thinkers, I hope that it is On Topic. The Peerless SLS woofer has a higher Qtc than other woofers. With the higher Qtc less air compression in the enclosure is needed to dial the total Q of the speaker (dirver and enclosure). This is the question, all other things being equal is there any difference in the stored energy performance between combination A, high Qtc driver + big box ,Q = 0.71 and combination B, low Qtc driver + small enclosure, Q = 0.71?
DT
All just for fun!
First the Peerlees needs a big enclosure and yes it will store more energy in the lower reaches simply because there IS energy. Think about it. It´s quite a shock to listen to speakers with full bass extention. Many novices will call the sound "slow" at first but when they switch back to their minimonitors they get another shock.
DT, reading your post again, in theory the two systems you proposed should perform the same given that the effiiency is the same. Problem is that the low Q woofer whould need more cone mass and a substantial magnet. I know from experience that you can not substitude a big box against a small one and expect the same subjective performance.
Hello Joachim,I am liking the Peerless woofers not picking on them. For my moderate size listening space i am thinking that the larger (40 cm) SLS woofers in 137L sealed enclosures will be solid down to 27Hz (-9db plus room effect). My question about stored energy is looking for better understanding the differences between using high and low Qtc speakers.
<edit> i missed your post #126, thank you for you insights.
DT
All just for fun!
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A speaker that is shallow in extention provokes less room resonances so it may sound more clean in the particular application. I think you can not go wrong with the 30cm version in a closed enclosure. If it booms simply put more damping material into it. Many people think that low Q woofer are "faster" but that is not the case given that you optimise the volume of the box.
Hi,
Simply logically this would be true. Except I never volountarily listen in the nearfield. And I may add that I am not much into "soundscape" and "3D", which are limited illusions (if nice to have) and value other factors.
Hmmm.
In classical physics, the diffraction phenomenon is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings. (wikipedia)
The process of sound appearing across a greater angle than 180 degrees with a minimal size tweeter would certainly fit this definition as diffraction (waves bending around obstacles - in this case the tweeter housing and magnet).
I have personally found the various approaches to minimum baffle speakers and indeed "maximum dispersion" types (e.g. Omni's) interesting, but in far-field conditions very unsatisfactory.
In conditions where listening is in the nearfield of the speaker, with all room surfaces much further from the listener than the speaker this may very well change, I just do not so far enjoy near field listening at all (and I hate 'can's).
That was the "different strokes for different blokes" part.
I do hope it works out the way you desire.
Ciao T
Simply logically this would be true. Except I never volountarily listen in the nearfield. And I may add that I am not much into "soundscape" and "3D", which are limited illusions (if nice to have) and value other factors.
Hmmm.
In classical physics, the diffraction phenomenon is described as the apparent bending of waves around small obstacles and the spreading out of waves past small openings. (wikipedia)
The process of sound appearing across a greater angle than 180 degrees with a minimal size tweeter would certainly fit this definition as diffraction (waves bending around obstacles - in this case the tweeter housing and magnet).
I have personally found the various approaches to minimum baffle speakers and indeed "maximum dispersion" types (e.g. Omni's) interesting, but in far-field conditions very unsatisfactory.
In conditions where listening is in the nearfield of the speaker, with all room surfaces much further from the listener than the speaker this may very well change, I just do not so far enjoy near field listening at all (and I hate 'can's).
That was the "different strokes for different blokes" part.
I do hope it works out the way you desire.
Ciao T
Ah, but *WHY* don't you enjoy listening in the "relative" near field?
"cans" are a whole 'nuther thing, and are actually more similar to a *reduced* dispersion field that you claim to prefer.
I have had sensational soundfield experience even with earphones when the recording was done with mic at the ears. It is true that diffraction is pretty strong when listening near field, but so is stored energy. The strongest diffraction comes from the driver itself, so it's necessary to do driver near field measurements (1mm~10cm) to find a driver with minum self diffraction. At this distance, basically we are trying to determine the best diaphram/surround design integration. Then, what we want to do is let diffraction in the pass band to be directed to generate into a direction at least 90 deg from the center axis.
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Hi Thorsten !
It may well be that we had that discussion on one of the High End shows. I respect and understand partly your aproach. I myself have no problem to listen in the nearfield or to headphones but i can understand that many will find that unnatural. I have designed speakers with waveguides too and my MPP has a rather big 20cm midrange and a treble horn. I listen to this system from maybe 3m. More is not posible in my room. What is important to me is focus and soundstaging. Thanks for finding a definition for diffraction.
When it is bending of waves around small obstacles then i whould modify my statement : This difracted energy should not interfer with the direct sound in such a way that combfiltering takes place, making the frequency response ragged. My ideal ZDL whoud then be a loudspeaker that has a linear on axis response and a linear off axis response with the exeption that the tweeter has a falling off axis response in the higher treble due to it´s finity size.
I find a tweeter that does not radiate the upper treble to the back an advantage in a ZDL. Concerning energy storage, first we need a linear frequency response but also a linear phase response. A speaker that does have an allpass term stores energy, even when the frequency response is flat.
It may well be that we had that discussion on one of the High End shows. I respect and understand partly your aproach. I myself have no problem to listen in the nearfield or to headphones but i can understand that many will find that unnatural. I have designed speakers with waveguides too and my MPP has a rather big 20cm midrange and a treble horn. I listen to this system from maybe 3m. More is not posible in my room. What is important to me is focus and soundstaging. Thanks for finding a definition for diffraction.
When it is bending of waves around small obstacles then i whould modify my statement : This difracted energy should not interfer with the direct sound in such a way that combfiltering takes place, making the frequency response ragged. My ideal ZDL whoud then be a loudspeaker that has a linear on axis response and a linear off axis response with the exeption that the tweeter has a falling off axis response in the higher treble due to it´s finity size.
I find a tweeter that does not radiate the upper treble to the back an advantage in a ZDL. Concerning energy storage, first we need a linear frequency response but also a linear phase response. A speaker that does have an allpass term stores energy, even when the frequency response is flat.
This would demand that the effective baffle width should be smaller than twice the membrane/cone diameter. In that case combfiltering should only occur at frequencies with wavelength below the baffle width.
Rudolf
Hi,
Because the whole sound image, picture and feel is wrong. I cannot describe it any better, sorry, but everything has a mickey mouse miniature feel to it. Lovely detail, maybe more than at greater distances, but miniature.
I only ever used near fields for tracking, never for any serious mastering, mixing or to listen for pleasure.
Note, this has zip to do with speakers disappearing, but with the whole perspective. I have heard nearfield monitors disappear and the same from far field systems.
Recordings are just not usually engineered to work under such conditions...
Not at all, they are completely unrelated. Again, most recordings are not engineered to work under such conditions, and they don't (they are good at giving me headaches though, which farfield systems never do).
Ciao T
Because the whole sound image, picture and feel is wrong. I cannot describe it any better, sorry, but everything has a mickey mouse miniature feel to it. Lovely detail, maybe more than at greater distances, but miniature.
I only ever used near fields for tracking, never for any serious mastering, mixing or to listen for pleasure.
Note, this has zip to do with speakers disappearing, but with the whole perspective. I have heard nearfield monitors disappear and the same from far field systems.
Recordings are just not usually engineered to work under such conditions...
"cans" are a whole 'nuther thing, and are actually more similar to a *reduced* dispersion field that you claim to prefer.
Not at all, they are completely unrelated. Again, most recordings are not engineered to work under such conditions, and they don't (they are good at giving me headaches though, which farfield systems never do).
Ciao T
No.. that's a good description. I get the same thing with higher freq.s and larger diameter full-range drivers when I move-in closer. (..though the lower midrange, depending on the loading and the freq. response, can occasional cause "bloat" instead.)
On the other hand with a design like Joachim is describing with small diameter drivers - the closer I move toward them, generally the larger the image gets (and it tends to become more diffuse). It *also* increases the sound-stage size, because you hear more lateral energy from direct sound.
Different design, different results.
Directive designs (at higher freq.s) are more similar to headphones because they tend to lower the effects of cross-correlation at higher freq.s. Of course if you use an extreme toe-in of the loudspeakers to achieve more stable off-axis imaging (Jordan) then this negates this attribute.
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Hello Gents,Lots of theories, options and egos.
More food for thought see diffraction - definition and meaning from Wordnik .
It is not just sharp edges that cause mutual interference, direct sound and sound reflected off a boundary; floor wall, obstruction, baffle or whatever. Any interference will cause illusion disrupting artifact. I believe that depending on the time and space any of the discussed speakers have merit.
I suppose the near field speakers that have the ability to disappear are the topic here.
DT
All just for fun!
Yes DT, that is the topic here. Nevertheless i am willing to discuss other options if they do not disturb my work here. It does not matter how you build a speaker, there will be always different opinions about it. First, it is at this point in time not posible to build the perfect speaker and when it happens " The perfect speaker will go unnoticed "; Peter Walker. Why is that ? Because it sounds like natue and that is totally unspectacular.
I had some more comunication with Mr.Stoll and he whould like me to explain the difference between sensitivity and efficiency because they are mixed up easily.
Instead of putting up some explanation myself i found a good tutorial on Wikipedia.
I had some more comunication with Mr.Stoll and he whould like me to explain the difference between sensitivity and efficiency because they are mixed up easily.
Instead of putting up some explanation myself i found a good tutorial on Wikipedia.
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