You can't control dispersion with the crossover >8kHz
And I rever to a ribbon off-axes like this -20dB 20kHz.
I measured it and it is the result off fast phase shift above 10kHz of a tweeter with poor of axes.
Good of axes horizontal is good sealing reflections are bad. So no need of poor off axes.
I listen to a set of magnepans in a small square living room with very good and wide sweet-spot. So good dispersion 180 degree is good I think.
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Hi,
First, I wrote that dispersion at low frequencies must be controlled with a waveguide AND that then equalisation is needed in the crossover to get a flat frequency response.
How you come from that to what you claimed to be what written (control dispersion with the crossover) is a mystery to me...
You are showing a magnetic planar driver without wave guide and one at that who has a poorely designed "phaseplug" (or whatever you want to call it), leading to a cancellation notch. This in turn is made to look worse by the way HiVi Measure...
For reference, here a magnetic planar tweeter with waveguide:
This is at 0/10/20/30 degrees.
It is taken from here, where you can find more information:
SWANS RT2H-
As Troels Gravensen remarks, recent production of the RT-2 no longer exhibits the notch around 20KHz, incidentally.
I am unclear what you measured, but the Watt does not use the D2606, never has.
I am really sorry, but I can make no sense whatsoever of what you rite above...
With respect, Magnepans, do not have 180 Degrees for most of their operational range...
Ciao T
First, I wrote that dispersion at low frequencies must be controlled with a waveguide AND that then equalisation is needed in the crossover to get a flat frequency response.
How you come from that to what you claimed to be what written (control dispersion with the crossover) is a mystery to me...
You are showing a magnetic planar driver without wave guide and one at that who has a poorely designed "phaseplug" (or whatever you want to call it), leading to a cancellation notch. This in turn is made to look worse by the way HiVi Measure...
For reference, here a magnetic planar tweeter with waveguide:
An externally hosted image should be here but it was not working when we last tested it.
This is at 0/10/20/30 degrees.
It is taken from here, where you can find more information:
SWANS RT2H-
As Troels Gravensen remarks, recent production of the RT-2 no longer exhibits the notch around 20KHz, incidentally.
I am unclear what you measured, but the Watt does not use the D2606, never has.
I am really sorry, but I can make no sense whatsoever of what you rite above...
With respect, Magnepans, do not have 180 Degrees for most of their operational range...
Ciao T
Hi,
The Crescendo Drivers are not available on the open market (they are quite unusual and special). The details and instructions are found on diyhifisupply's website:
Crescendo Ribbon Horn Speaker System | Diy HiFi Supply
Unlike the Watt/Puppy it does not look fancy, this is mainly due to a cabinet construction that is meant to be achievable with simple tools and straight cuts.
You can use whatever you like, but that would be then your own design and you would have to design it.
Ciao T
The Crescendo Drivers are not available on the open market (they are quite unusual and special). The details and instructions are found on diyhifisupply's website:
Crescendo Ribbon Horn Speaker System | Diy HiFi Supply
Unlike the Watt/Puppy it does not look fancy, this is mainly due to a cabinet construction that is meant to be achievable with simple tools and straight cuts.
You can use whatever you like, but that would be then your own design and you would have to design it.
Ciao T
I am only talking Dispersion above 8kHz what is poorer with most planar drivers
That one I did see also it is indeed very nice result for a planar tweeter. So a wave-guide can improve the top end very much.
I am only talking Dispersion above 8kHz what is poorer with most planar drivers
I am talking about dispersion of planar tweeter comperad to dome tweeters. And the result in stereo at your listening position. Not the design of the WP.
What I read and combined with own experiences I come to the conclusion reflection at the sides are increasing qaulity and reflections of the sealing are negative to sound quality
That can be I was thinking of the radiation pattern of a dipole.
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Hi,
No, it does not improve top end dispersion or the high frequencies, it merely narrows lower frequency dispersion. As you can see above around 8KHz the driver rolls off gently at most angles. This is what I call "CD rolloff" and which I point out needs to be equalised in the crossover.
Once done the driver will be flat up to where the EQ runs out of boost. If you combine this driver with an "average" 87dB/2.83V/1m woofer we around 7dB to boost and can get to well past 20KHz for "flat" response across a fairly substantial dispersion angle.
Incidentally, the actual "driver" is precisely the same that you showed as extremely poor, only the front plate differs...
Sorry, this thread was talking about the design of the WP primarily.
I disagree, ALL reflections obscure the original recording, but some are worse at that (vertical reflections) than others (lateral). However, strong lateral reflections still are a "bad thing", unless you like your musical menu with a hefty serving of reverb sauce (the musical equivalent of MSG).
With respect, dipoles too do not have 180 degrees radiation angle.
In fact, Dipoles, like mangepan's are strongly directional both vertical and lateral. However their rear output can present a problem if not sufficiently diffused, absorbed and delayed...
Ciao T
No, it does not improve top end dispersion or the high frequencies, it merely narrows lower frequency dispersion. As you can see above around 8KHz the driver rolls off gently at most angles. This is what I call "CD rolloff" and which I point out needs to be equalised in the crossover.
Once done the driver will be flat up to where the EQ runs out of boost. If you combine this driver with an "average" 87dB/2.83V/1m woofer we around 7dB to boost and can get to well past 20KHz for "flat" response across a fairly substantial dispersion angle.
Incidentally, the actual "driver" is precisely the same that you showed as extremely poor, only the front plate differs...
Sorry, this thread was talking about the design of the WP primarily.
I disagree, ALL reflections obscure the original recording, but some are worse at that (vertical reflections) than others (lateral). However, strong lateral reflections still are a "bad thing", unless you like your musical menu with a hefty serving of reverb sauce (the musical equivalent of MSG).
With respect, dipoles too do not have 180 degrees radiation angle.
In fact, Dipoles, like mangepan's are strongly directional both vertical and lateral. However their rear output can present a problem if not sufficiently diffused, absorbed and delayed...
Ciao T
I know and it still is about -15dB at 20kHz. But up to 15khz -5dB it looks decent I personaly can only hear up to 13khzHi,
No, it does not improve top end dispersion or the high frequencies, it merely narrows lower frequency dispersion. As you can see above around 8KHz the driver rolls off gently at most angles. This is what I call "CD rolloff" and which I point out needs to be equalised in the crossover.
Once done the driver will be flat up to where the EQ runs out of boost. If you combine this driver with an "average" 87dB/2.83V/1m woofer we around 7dB to boost and can get to well past 20KHz for "flat" response across a fairly substantial dispersion angle.
Incidentally, the actual "driver" is precisely the same that you showed as extremely poor, only the front plate differs...
read this interview it is tested long ago.Searching for the Extreme: Andrew Jones of Technical Audio Devices
Søren Bech, from the University of Copenhagen, led the project, and we thought it would be a good idea to scientifically investigate the importance of room acoustics. The interface of the loudspeaker into a room is a three-dimensional issue, and what you hear in any room is directly affected by room characteristics. What is important about room characteristics? People had theorized, people had done simplified experiments. Our thought was to see just how far we could go to really determine the importance of the characteristics of the room.
Starting with one of the University’s largest anechoic chambers, we put in an array of 32 loudspeakers surrounding the listener (front, back, and sides, both below and above) on a 5m arc (an imaginary sphere). Curtains were placed around the listener so they couldn’t see the speakers. If you went into the chamber and sat in the listening seat, and if only a stereo pair of speakers (left and right) were programmed to play, it would sound simply awful. (Never listen to music in an anechoic chamber, by the way. This is actually quite interesting when we come to talk about important room characteristics and the significant difference between how you set up for home theater vs. music reproduction.)
We designed our own modeling program, such that we could model a simplified room (a rectangular room) and calculate the appropriate image. Imagine every surface is a mirror, so every reflection from the walls produces an image of the speaker (i.e., on the other side of the wall, at the appropriate angle, at the appropriate distance). We could calculate exactly where all of these images would appear, how far away (i.e., how attenuated), what angle the sound traveled from the original speaker to the listener. If you know the directional characteristics of your “simulated” speaker, you can calculate the frequency response, delay, and strength of every single image, and feed that into a DSP program. We built (this is early 1980s) a 32-channel DSP engine, which simply didn’t exist in those days. Our program simulation could calculate every image -- hundreds of images, if you calculate through the third reflection. We then created an algorithm to group the images from a particular direction (the ear has only a limited acuity to directional cues -- everything within a certain solid angle is fused into one image). We would look for groups to bring it back to 32 images, which we felt sufficient. For the decay of the sound from the farthest images, room reverberation, the calculations became impractical. Even with all that DSP, there was a limit. So our algorithm included reverberation calculations, the low-level end of the tail for a room of particular dimensions and approximate absorption characteristics. Without adding reverberation, it just never sounded right.
I had the same idea as you describe and build my latest system with a kugelwellen horn and a OB basmid to have controlled dispersion with less reflections of the listening-room. It sound very good and good efficiency thanks to the refection of the backwall nice response down to 20Hz -3dB 30Hz at a efficiency 94dB 1Wmtr. I am very pleased with the result. But i was also very pleased with the D'appolito designs I made(better horizontal dispersion), the fatboy project made the sound stage appear wider. And as I already said the magnepans performed very well with dipole reflections in a small square living room.
Not my experience. I ask my self if you think that or that you have done real experiments with a dipole like the magnepan.
Due the haas effect we can hear witch direct wave we hear and witch one is delayed below 1kHz "so maybe not a real problem then".
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Hi,
You WHAT? According to the measurements by TG it is 4dB down at 20KHz...
It is one view. Not necessarily the correct one. The Gentleman at the IRT for example may demur...
That is not my idea nor did I describe or suggest anything of the like.
Let me see now.
The first dipole speaker I encountered was at around age six (you may more say it entered my conciousness, as it was there before). It was a big Stassfurt "Dampfradio" and connecting our Record Player (horribly tinny sounding transistor thingey, but stereo and also with dipole speakers) to it became an obsession, eventually achieved with the help of an Uncle who was an EE around 2 years later. It sounded totally awesome and had these sound register buttons, like "Speech", "Jazz", "Classical"...
I re-encountered dipoles in the original ME Geithain RL900 Studiomonitor in the then DDR, in a number of studio's, though it is more a modified dipole with cardiod response. After I moved to the west I ended up with JBL Monitors but was considering ACR K-Horns and was lusting after JBL Everest...
When I moved to the UK in the early 90's I came across Quads and also the then revolutionary SD Acoustics SD-1 (and of course BBC Monitors, Linn Isobarik's and the like), though I ended up owning Sony APM-6's after passing on some Infinity Kappa-6 which I also liked immensely (driven from a Technics "AA" Amp, with a Sansui DD Turntable, a Sony Tape Deck and a Fisher/Sanyo Non Oversampling Multibit CD-Player FWIW).
I got into real "high end" after hearing a friends Watt/Puppy system with an Audio Note Ongaku which prompted me to go into tubes and build some decent copies (with the help of several people on the then "Bass" E-Mail list in the very early days of the net)...
Since, I have owned or had available (I used to review HiFi) pretty much any crazy speaker for a while, from Lowther Horns to Tannoy Corner Yorks with 15" Monitor Reds to Supravox Fieldcoil Drivers on open baffles (and other stuff between).
I have worked with friends on massive (like considerably taller than my 5'10") DIY ESL & Dipole Sub systems with the ESL's driven transformerless drom DHT Push-Pull Amplifiers, I also (as it so happens) worked on quite a few dipoles using cone drivers, including a commercial one...
Deco Audio Speakers2
I have also worked (and am still working) on electronically steered LF cardioid speakers with pure acoustic MF/HF cardioid's and even (so far concept only) fully steered directivity speakers...
Oh and in my misspend youth I worked as sound engineer for bands (which in the DDR meant you had to take a course and learn as well as being graded on recording "ernste musik"...
So I guess, no.
I never experimented with Maggies much myself. In my experience they sound charming but struggle majorly with dynamics, I would call them "leisesprecher" (quietspeaker) and "basslose frecheit" (bass-less insult).
My current own speakers are remarkable only for how boringly conventional and traditional they are.
Oh and for their sound. A classical and early music loving friend of mine owns a full Lyngdorf system, with the dipole main speakers. Upon hearing my boring speakers (plus tube amp, tube preamp, tube Non Oversampling DAC and PC frontend) he exclaimed "Now this is just perfect, how do I get this sound?".
I had to tell him that he cannot, as the key drivers are no longer available and anyway, he cannot pay me enough to build him a copy of my system...
Non of all of that amounts to a hill of beans at that of course. If you like what you have you like it and be happy and enjoy. It does not mean you are right and I am wrong, just as my friends like of my boringly conventional speakers does not mean I am right and you are wrong...
"Letting a hundred flowers blossom and a hundred schools of thought contend is the policy for promoting progress in the arts and the sciences and a flourishing socialist culture in our land." Mao Zedong
Ciao T
You WHAT? According to the measurements by TG it is 4dB down at 20KHz...
It is one view. Not necessarily the correct one. The Gentleman at the IRT for example may demur...
That is not my idea nor did I describe or suggest anything of the like.
Let me see now.
The first dipole speaker I encountered was at around age six (you may more say it entered my conciousness, as it was there before). It was a big Stassfurt "Dampfradio" and connecting our Record Player (horribly tinny sounding transistor thingey, but stereo and also with dipole speakers) to it became an obsession, eventually achieved with the help of an Uncle who was an EE around 2 years later. It sounded totally awesome and had these sound register buttons, like "Speech", "Jazz", "Classical"...
I re-encountered dipoles in the original ME Geithain RL900 Studiomonitor in the then DDR, in a number of studio's, though it is more a modified dipole with cardiod response. After I moved to the west I ended up with JBL Monitors but was considering ACR K-Horns and was lusting after JBL Everest...
When I moved to the UK in the early 90's I came across Quads and also the then revolutionary SD Acoustics SD-1 (and of course BBC Monitors, Linn Isobarik's and the like), though I ended up owning Sony APM-6's after passing on some Infinity Kappa-6 which I also liked immensely (driven from a Technics "AA" Amp, with a Sansui DD Turntable, a Sony Tape Deck and a Fisher/Sanyo Non Oversampling Multibit CD-Player FWIW).
I got into real "high end" after hearing a friends Watt/Puppy system with an Audio Note Ongaku which prompted me to go into tubes and build some decent copies (with the help of several people on the then "Bass" E-Mail list in the very early days of the net)...
Since, I have owned or had available (I used to review HiFi) pretty much any crazy speaker for a while, from Lowther Horns to Tannoy Corner Yorks with 15" Monitor Reds to Supravox Fieldcoil Drivers on open baffles (and other stuff between).
I have worked with friends on massive (like considerably taller than my 5'10") DIY ESL & Dipole Sub systems with the ESL's driven transformerless drom DHT Push-Pull Amplifiers, I also (as it so happens) worked on quite a few dipoles using cone drivers, including a commercial one...
Deco Audio Speakers2
I have also worked (and am still working) on electronically steered LF cardioid speakers with pure acoustic MF/HF cardioid's and even (so far concept only) fully steered directivity speakers...
Oh and in my misspend youth I worked as sound engineer for bands (which in the DDR meant you had to take a course and learn as well as being graded on recording "ernste musik"...
So I guess, no.
I never experimented with Maggies much myself. In my experience they sound charming but struggle majorly with dynamics, I would call them "leisesprecher" (quietspeaker) and "basslose frecheit" (bass-less insult).
My current own speakers are remarkable only for how boringly conventional and traditional they are.
Oh and for their sound. A classical and early music loving friend of mine owns a full Lyngdorf system, with the dipole main speakers. Upon hearing my boring speakers (plus tube amp, tube preamp, tube Non Oversampling DAC and PC frontend) he exclaimed "Now this is just perfect, how do I get this sound?".
I had to tell him that he cannot, as the key drivers are no longer available and anyway, he cannot pay me enough to build him a copy of my system...
Non of all of that amounts to a hill of beans at that of course. If you like what you have you like it and be happy and enjoy. It does not mean you are right and I am wrong, just as my friends like of my boringly conventional speakers does not mean I am right and you are wrong...
"Letting a hundred flowers blossom and a hundred schools of thought contend is the policy for promoting progress in the arts and the sciences and a flourishing socialist culture in our land." Mao Zedong
Ciao T
Again I am talking of axes dispersion see yellow line 30 degrees about -15dB 20kHz. I would like to see 60 degrees to
Nor did I suggest you did. I did second your idea about limited dispersion and compared it to my own current system that I build with this design goal.
The magnepan I did hear had to much subbas in fact and it was not silent with a tweaked 2X hypex 400 class-D amplifier.
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Hi,
I fail to see the point. Who would want to listen 60 degrees (or even 30 degrees) off axis? If you want sound that fills the room, get "direct reflecting" or "omni" type speakers...
Maybe we are not talking about the same Magnepan Speakers?
The ones I know have horrible and very non-flat on axis response and even worse off axis response, a massive > 10dB mid-bass hump and no low, never mind sub-bass and are about as efficient as a LS3/5...
Magnepan Magneplanar MG1.6/QR loudspeaker Measurements | Stereophile.com
They do have pretty nice impulse response and a reasonable CSD...
Ciao T
I fail to see the point. Who would want to listen 60 degrees (or even 30 degrees) off axis? If you want sound that fills the room, get "direct reflecting" or "omni" type speakers...
Maybe we are not talking about the same Magnepan Speakers?
The ones I know have horrible and very non-flat on axis response and even worse off axis response, a massive > 10dB mid-bass hump and no low, never mind sub-bass and are about as efficient as a LS3/5...
Magnepan Magneplanar MG1.6/QR loudspeaker Measurements | Stereophile.com
They do have pretty nice impulse response and a reasonable CSD...
Ciao T
It is needed to have a bigger/wider useful sweet spot.
It was this model and room(4X5mtr).
This is one driver about 1 mtr 20msec see photo.
This was a stereo mls on listening position 40msec in the living room from about 4X5 meter. Looks like it isn't right, never the less it sounded very good wide sweet-spot. Only the 30Hz rise was to much althoug I like bas. I listened to "radio activety of kraftwerk was very impressive" 2X 400W class-D amp hypex and i think tube pre-stage knowing the owner.
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Hi,
At 3m listening distance having a 40 degree listening window is pretty generous, I'd estimate well over 2m wide, if I remember my geometry classes right (it's a wee bit long ago now)...
Not sure which model this is, MG20's?
On axis. What does 30 degrees off axis looks like.
It looks like a classic tonecontrol bass & treble turned up all the way, not sure what it would sound like and why it would measure like that...
If you arranged the speakers right I would expect a wide sweetspot from using quite directive speakers such as maggies. You need to set them up similar to how JBL's asymmetric coverage horns worked, so that as you move closer to one speaker you move more off axis, this keeps the stereo image quite stable, it usually means a quite dramatic toe in though that many people dislike the look of.
I suspect this is the 5m dimension halfwave room mode (around 35Hz which is what it looks like on the FR), not the speaker itself. Seems the coupling is very good to this mode due to your placement.
Ciao T
At 3m listening distance having a 40 degree listening window is pretty generous, I'd estimate well over 2m wide, if I remember my geometry classes right (it's a wee bit long ago now)...
It was this model and room(4X5mtr).
Not sure which model this is, MG20's?
This is one driver about 1 mtr
On axis. What does 30 degrees off axis looks like.
It looks like a classic tonecontrol bass & treble turned up all the way, not sure what it would sound like and why it would measure like that...
If you arranged the speakers right I would expect a wide sweetspot from using quite directive speakers such as maggies. You need to set them up similar to how JBL's asymmetric coverage horns worked, so that as you move closer to one speaker you move more off axis, this keeps the stereo image quite stable, it usually means a quite dramatic toe in though that many people dislike the look of.
Only the 30Hz rise was to much althoug I like bas. I listened to "radio activety of kraftwerk was very impressive"
I suspect this is the 5m dimension halfwave room mode (around 35Hz which is what it looks like on the FR), not the speaker itself. Seems the coupling is very good to this mode due to your placement.
Ciao T
These are the only measurtments I have not the off axes
It is like a loudness-curve.
I discussed the result with the owner back then, it shows the rear-wall reflection and the harmonics of that reflection is my conclusion. It is at 30hz a 1/4 to1/2 wavelength reflection of the rear-wall (about 2,2 to 4,4mtr average in that room) that is in phase with the front radiation.
Here on a other scale it looks less shocking.
An externally hosted image should be here but it was not working when we last tested it.
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Hi
Just a quick point.
Imagine every surface is a mirror, so every reflection from the walls produces an image of the speaker
I disagree. The reflections from walls and other surfaces are highly non-linear, so the analogy of a mirror does not hold water. Sound hitting a surface is selectively reflected and absorbed, which along with size and shape gives a specific room-sound. Just my $0.02.
Enjoy,
Deon
Just a quick point.
Imagine every surface is a mirror, so every reflection from the walls produces an image of the speaker
I disagree. The reflections from walls and other surfaces are highly non-linear, so the analogy of a mirror does not hold water. Sound hitting a surface is selectively reflected and absorbed, which along with size and shape gives a specific room-sound. Just my $0.02.
Enjoy,
Deon
HY BFARD
I would like to make the watt and puppy can you help me??????thank you
best franck
I would like to make the watt and puppy can you help me??????thank you
best franck
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