I am also thinking about trying out the analog notch filters technique in below article for the Satori driver 
at least the notch filter part. Rest all DSP crossover.
https://purifi-audio.com/tech/ (Low Distortion Filter for PTT6.5X04-NAA)
In addition to getting the notch, there seems to be a free benefit of significantly reducing the breakup resonance-amplified distortion products, which show up as subharmonic peaks in the distortion spectrum.
I had tried to play the WO24P without filtering. It is almost un-listenable when played full range. Sort of echoey sound. Makes one want to cover ears..
Notching the breakup peak, even actively, makes a lot of difference to the sound. Now I am thinking, I see rise in harmonic distortion and resonances in the impedance and HD plots of the driver here:
https://hificompass.com/en/speakers/measurements/satori/satori-wo24p-8
Would this kind of passive notch make a difference with the woofer and the CD (which also has a big breakup peak around 15.5kHz)?
at least the notch filter part. Rest all DSP crossover.https://purifi-audio.com/tech/ (Low Distortion Filter for PTT6.5X04-NAA)
In addition to getting the notch, there seems to be a free benefit of significantly reducing the breakup resonance-amplified distortion products, which show up as subharmonic peaks in the distortion spectrum.
I had tried to play the WO24P without filtering. It is almost un-listenable when played full range. Sort of echoey sound. Makes one want to cover ears..
Notching the breakup peak, even actively, makes a lot of difference to the sound. Now I am thinking, I see rise in harmonic distortion and resonances in the impedance and HD plots of the driver here:
https://hificompass.com/en/speakers/measurements/satori/satori-wo24p-8
Would this kind of passive notch make a difference with the woofer and the CD (which also has a big breakup peak around 15.5kHz)?
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A bit more impressions before I take off for a week.
The prototype single speaker system has been sounding so good to my ears that I have started wondering about what I am trying to achieve technically and audibility wise with these two parallelly running projects (2 way horn, with Rosso65CDN-T, and the initial 3 way project)..
The compression driver has been sounding so good that I would recommend it to anyone on the lookout for 1.4inch CDs.
Again and again, I am hearing new things in songs without even paying much attention to the system. Whereas I used to keenly listen for new things in past small speaker projects.
I had all sorts of apprehensions initially thinking about the titanium diaphragm on the CD, the very narrow directivity of the current horn, and the midrange capability of the Satori drivers. But all that has been put to test and to rest in the last two days.
Maybe all this is because I am hearing a horn-based system properly for the first time.
To think that it is going to get better from here on is very very exciting..
And as tmuikku said before, sometimes the jaw drops hearing the system..
The prototype single speaker system has been sounding so good to my ears that I have started wondering about what I am trying to achieve technically and audibility wise with these two parallelly running projects (2 way horn, with Rosso65CDN-T, and the initial 3 way project)..
The compression driver has been sounding so good that I would recommend it to anyone on the lookout for 1.4inch CDs.
Again and again, I am hearing new things in songs without even paying much attention to the system. Whereas I used to keenly listen for new things in past small speaker projects.
I had all sorts of apprehensions initially thinking about the titanium diaphragm on the CD, the very narrow directivity of the current horn, and the midrange capability of the Satori drivers. But all that has been put to test and to rest in the last two days.
Maybe all this is because I am hearing a horn-based system properly for the first time.
To think that it is going to get better from here on is very very exciting..
And as tmuikku said before, sometimes the jaw drops hearing the system..
Hi hifijim,
I didn't abandon the original 3 way project. All i did is split that rockport type cabinet into two parts. A two Satori driver per box bass/mid module and a top module which houses the smaller mid + tweeter. I was just pausing on the mid+tweeter module which i originally designed to see what happens with the directiva R2 peoject. It uses the same mid + waveguided tweeter configuration. I hope that I can also do something similar but with slightly different directivity control given by my tweeter on the elliptical waveguide. I need to learn the strategy they employ in the box for the passive cardioid mid.
This compression driver will eventually go along with a Faital pro 15pr400 driver which will have its own 100+ Litre triangular shaped (apprpximation of the teardropish shape) box. The horn will also be changed to an ES600 biradial or a yuichi type horn.
I am also thinking about the SB CDC tweeter going on a tritonia waveguide as another top module for the satori box or some custom waveguide designed using ATH tool.
All I am doing currently is creating (or atleast i would like to hope that this is what i am doing) a base (bass-mid modules) for further experimentation in future with different top modules/flavours of presentation/directivity control. Be it passive cardioid top/coaxial top/horn top.
Speakers designed and eq'd to sound right from the corner is the best choice for a small room - semi-nearfield IMO! Corner placement minimizes early reflections, helps in midrange clarity and imaging. Problem is very strong room modes in low bass. A challenge is to be able to sit right between speakers.
Hi @augerpro,
I have a very basic question.
How did you install the CLD bracing in the below pic:
Were the pieces of the braces attached to each panel glued already while making the box itself using the CLD panels or were the braces were attached separately (a pair connecting opposing panels, at a time) to a pre made CLD box?
Thanks
Vineeth
I have a very basic question.
How did you install the CLD bracing in the below pic:
Were the pieces of the braces attached to each panel glued already while making the box itself using the CLD panels or were the braces were attached separately (a pair connecting opposing panels, at a time) to a pre made CLD box?
Thanks
Vineeth
I have some general questions.
Based on what guidlines do we choose directivity index (DI) at different frequencies in a design. Is it eventual system placement in a room? Or is it dictated by choice/type of transducers?
What is more preferable, constant directivity over a wideband (700 Hz to 7kHz?) or a rising DI caused by a horn/waveguide etc.
What is more preferred?
Based on what guidlines do we choose directivity index (DI) at different frequencies in a design. Is it eventual system placement in a room? Or is it dictated by choice/type of transducers?
What is more preferable, constant directivity over a wideband (700 Hz to 7kHz?) or a rising DI caused by a horn/waveguide etc.
What is more preferred?
Mmmmhh, hi! The 'constant directivity' is to be applied to a field, an area, a real space. This answers to your first question relative to speaker ( or speaker geometry starting from the membrane ) system in a room.
The question of DI : directivity is always increasing as you progress in frequency the source beams. Be-a-ming : the sound becomes laser pointed at treble frequencies, and this occurs naturally regardless of what kind of source ( i.e. an instrument and a reproduced instrument ).
This is what I get from simple acoustics observations, if you agree...
The question of DI : directivity is always increasing as you progress in frequency the source beams. Be-a-ming : the sound becomes laser pointed at treble frequencies, and this occurs naturally regardless of what kind of source ( i.e. an instrument and a reproduced instrument ).
This is what I get from simple acoustics observations, if you agree...
After the box was glued up, I glued one brace on a side and one on the bottom. Use wood glue. After that is cured, I applied constrained layer to 2" of the end, and wood glue to the other and attach it just as you see it for the side brace. For the top make a piece of wood to sit across the box, so the brace as something to butt up against like the baffle. Apply the constrained layer to 2" of the end and put it in place. I'll attach a bit of tape to it and wood piece it touches so it doesn't slide down while it cures. I really need to make a video, it's so easy when you see it, but sounds more complicated to explain.
No one has done any big studies on what directivities are preferred, just that the off axis should have similar character to the on axis, and all should be smooth and straight.
No one has done any big studies on what directivities are preferred, just that the off axis should have similar character to the on axis, and all should be smooth and straight.
Thanks augerpro
I think i got some basic idea about how to do the CLD bracing.. I will read a few more times and attempt to do it next week..
The doubt regarding directivity is, these days, I am seeing everyone trying to achieve constant like DI over a wider range of frequencies. So I started wondering whether some horns/waveguides designed in the past that have rising DI at higher frequencies is a faulty design choice or something.
For example the Faitalpro LTH142 horn vs eighteen sound 1464 horn.
For example the Faitalpro LTH142 horn vs eighteen sound 1464 horn.
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Mmmmhh, hi! The 'constant directivity' is to be applied to a field, an area, a real space. This answers to your first question relative to speaker ( or speaker geometry starting from the membrane ) system in a room.
The question of DI : directivity is always increasing as you progress in frequency the source beams. Be-a-ming : the sound becomes laser pointed at treble frequencies, and this occurs naturally regardless of what kind of source ( i.e. an instrument and a reproduced instrument ).
This is what I get from simple acoustics observations, if you agree...
Really? I think that that applies only to a single conventional transducer, and even then a cone/dome planar are different.
I understood that vineeth is asking about a multiway system "design". And this is a very importnt question! The designer must have a clear goal regarding directivity changes through audio band! And also "how low I want directivity to start. Horizontal vs. vertical directivity must be considered too.
Consumers in general (even most hifists) have no clue of this! But they notice differences in how speakers work in different rooms and positioning. Also "stereo imaging" is different because of different DI.
Tests/reviews of loudspeakers, with DI spectrum
https://www.princeton.edu/3D3A/Directivity.html
https://www.audiosciencereview.com/forum/index.php?pages/SpeakerTestData/
https://www.erinsaudiocorner.com/loudspeakers/
Thank you Juhazi for the links.. I will go through them.
You are right. I am interested in multiway speaker design and the questions were posted considering that aspect
Thank you for pointing this out..
In that case how do we compare the horozontal directivity shown in the attached plot vs XT1464 or LTH142.
My doubt is if the XT1464 type directivity is right/more preferable, what can be the objective in designing a waveguide with directivity shown in attached plot?
My question is not specific tonattached plot.
For example, constant directivity is best kind of discussion is also given in this page
http://gainphile.blogspot.com/?m=1
Attachments
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The more similar the directivity to the first plot on the link, the more constant the directivity is.
I think bot the XT1464 and the LTH142 are very good, they are sligtly narrowing with more-less deviation here and there.
Maybe someone who have more knowledge can explain better.
But the quick questions, that comes to my mind:
- the more constant is audible?
- if audible, then it's preferable?
- if preferable, by whom, where and with what sound material?
- is it worth the effort at all to get as constant directivity as possible?
There was shootout between the JBL M2 (constant directivity) and the Revel Ultima Salon 2 (wider dispersion with slightly narrowing response):
https://www.avsforum.com/threads/sp...akers-ever-made.2907816/page-18#post-54628832
DI can be calculated from frontal or 360deg measurements, even with only horizontal, but best in 3D like Klippel NFS
Gainphile claims that constant directivity is best (goal) and sounds best. That may apply to his own designs , but he measured only frontal horizontal dispersion! In Princeton Univ. study we notice that his design (like all of his dipoles) have practically zero radiation backwards above 1-2kHz. When his speaker is set up in a room, listening spot response most likely is falling towards treble!
Harman/Toole & Olive studies often cited are based on normal monopole loudspeakers, which have DI rising towards treble and give sloping room response. And this kind of behaviour was regarded to sound best (using one speaker in test room). But treble must not become too low, this is why many people however like speakers with on-axis treble response rising above average.
The fun and educative thing about speaker-diy is to make different kind of speakers, with different kind of dispersion profiles! When we measure and listen to them at home (or at friend's) for longer period we gradually learn what we personally prefer best. But the fellow diyer has her/his different opinion... For example I have listened to several diy horn speakers, and they sound too much like headphones IMO.
Gainphile claims that constant directivity is best (goal) and sounds best. That may apply to his own designs , but he measured only frontal horizontal dispersion! In Princeton Univ. study we notice that his design (like all of his dipoles) have practically zero radiation backwards above 1-2kHz. When his speaker is set up in a room, listening spot response most likely is falling towards treble!
Harman/Toole & Olive studies often cited are based on normal monopole loudspeakers, which have DI rising towards treble and give sloping room response. And this kind of behaviour was regarded to sound best (using one speaker in test room). But treble must not become too low, this is why many people however like speakers with on-axis treble response rising above average.
The fun and educative thing about speaker-diy is to make different kind of speakers, with different kind of dispersion profiles! When we measure and listen to them at home (or at friend's) for longer period we gradually learn what we personally prefer best. But the fellow diyer has her/his different opinion... For example I have listened to several diy horn speakers, and they sound too much like headphones IMO.
I think there are a couple of aspects of this to consider. Where do you want to listen and in what kind of environment. The room where you have measured seems to have a lot of hard reflective surfaces. A narrower coverage pattern changes the balance of direct to reflected energy. Do you want to listen in one spot only, across a couch or in the whole room. The narrow coverage pattern will work better for a single position but as you move outside the coverage pattern the sound will change more.
There is an element of this in the DI of the speaker. If the DI is flat the sound will be very consistent over the whole coverage pattern, if the DI rises the sound will change more within the coverage pattern based on position.
If the DI is flat and the on axis is also flat, the speaker will sound bright with most existing recordings. If the DI rises and the on axis is flat the sound will be closer to "right" with existing recordings without needing EQ.
What is best and preferred will be a matter of balancing these competing priorities, there is no one universal right answer.