Not bad for an old man.
I think you meant to write "most western males over age 12 cannot hear above 17,000 Hz", not 7000 Hz.
I tested a 8 year old male who could hear to 22kHz, as high as my RTA reads, so I couldn't tell if the ribbon tweeter went any higher than his hearing.
Anyway, this is what is more typical for presbycusis:
There comes an age when the sparkle is gone, whether it's produced or not 😢
Art
Here I am! Sorry for my absence, but I've been busy, and in the meantime I've been thinking about your advice, thinking a lot, studying a lot, learning all I could, for now...
Following rickmcinnis-1965's advice, I've been studying Synergy horns, and I've decided to go that route.
In my opinion, there is something magical about the point source concept, applied as Danley thought of it.
The theory is simple, but I quickly realized that the success of the project relies on small modifications, as well as good design...
I've started playing with horn resp, and I'm beginning to understand it...I'm doing some simulations as an offset drive, the simulations in multiple entry I can't complete yet, but we'll talk about that later, for now I'd like to start by asking you for design advice.
Objectives: Synergy 3-way speaker, hifi destination, which will be completed with a sub, about from 80Hz down...
I'd like to be able to listen at low volumes, without background noise (I'll think about amplification later, which will be class D for the power amps anyway), and be able to get to 120dB at need.
Opening angle 70° horizontally (minimum), 50° vertically.
I simulated to begin with (with google sketchup) the SH50 model produced by Danley, after going to read many threads (many of them here on DiyAudio, thank you), I also read the patent published by Danley sound lab.
I quote “The lower driver is located at a position along the horn passage where the passage has a preselected cross-sectional area that is no greater than the area of a round cross-section with a CIRCONFERENCE equal to a wavelength at the upper end of the frequency.
Please tell me now, if what I have understood is correct...
Assuming a distance between the CD diaphragm and the horn throat of 3cm, and a crossover frequency at 1200Hz with the MID driver, we can calculate:
Speed of sound 331.2 m/s + 0.6 x temperature in °C (assume 20°) = 343.2m/s
wavelength 343.2/1200Hz = 28.6cm
The distance of the input holes, from the CD diaphragm, must be 28.6/4 = 7.15cm.
First question: at this distance, should the center of the hole be located, or should the hole start there, and continue outward from the horn?
Also, since several Synergy designs are rounded in the corners, should the hole still be as close to the edge as possible? Or is it better to create it a little more centrally, without touching the corner rounding?
According to the patent, now I have to calculate the radius of the circle having the full wavelength as circumference, so 28.6/3.14159/2 = 4.55cm
At this point, assuming a 1.4” CD, with throat area 3.6x3.6cm, and 3 cm distance from the aperture to the throat, the prototype would look like this:
As I understand it, this is the ideal ratio between the distance of the emission centers and the area of the horn where the wavelength can no longer put pressure on the walls, right?
And here, we bring in the mids.
The first thing I realized is that if we want to keep the horn walls straight and the ideal ratio, the opening angle will be decided by these 3 parameters:
CD output diameter, distance of the CD diaphragm from the throat, crossover frequency with the MID.
So, the frequency of crossing between MID and WF, will be decided by us, but we should correct it to adapt to the already set angle, always if we want to try to keep the ratio.
Changing the crossover frequency between DC and MID is not recommended, because we have more chances to play on the low side, than above...
The relationship, it is no longer ideal...
The circumference of the WL is close to the edge, but does not touch it for 0.7cm.
By moving to the crossover frequency at 390Hz, we lower this distance to about 0.4cm.
Question 2:
This small distance, can cause problems in charging the horn at crossover frequency? Or will the two drivers, MID and WF, by collaborating (and equalizing them) be able to reproduce a flat response anyway?
This trumpet has an output of 67x67 degrees, but it is not what I would like...
Let’s complicate things a little...
Let’s assume that we want to create a horn with 50Vx70H degrees, driver from 1.4, crossover MID at 1Khz, this is the start:
As you can see, if you keep the correct distance of 1/4 WL from the CD’s diaphragm, the circumference of the WL at 1Kh is no longer in symmetry, and it breaks off from the edge of the narrow side by about 2mm, while it exceeds the wall of the wide side by 1.1cm.
The same will of course happen for WF...
So? The air no longer puts pressure on the corners at this point, but maybe the insertion of the mids will create turbulence in the crossing zone?
If I insert the mediums, the horn will not load some frequencies, with the risk of finding me with holes that I would not be able to correct then with dsp...
Question 3: What is the best way in this case? Will the dsp solve these problems if the horn is built like the above figure?
Now, let’s get to my idea:
I would build a 3 way Synergy, size is not an issue, using 1xFaital 12FH510, 2/4xFaital 4FE35 (maybe even a 3") and Cd Radian 745Neo.
Question 3: Has anyone tried this CD? I have no way of hearing anything here in Northern Italy, so I must rely on the opinions of other fans...
What about the exit of the throat? It’s a 10°, but I haven’t seen many people talking about the exit anchors in the Synergy horns, unlike other horns...
Are there any better CDs as a feature? Or being a 50x70 trumpet, not one would be good?
Any inventions? Forward rephasing rings?
I’ve already simulated the woofer in Hornresp, with good results (if I didn’t make mistakes)...
I would insert it in the narrow side, so that we can approach it to get in the air inlet holes...
I should be able to get up to 120dB with a single woofer, and besides saving money, this would be useful because the positioning in my room would be more convenient, and I have some ideas for the final aesthetic...
I have read about projects that use only one woofer, but I don’t understand how this can work optimally without its "twin" on the other side...
I do not want to use the rear reflex charging, I would close the back...
Question 4: Will one woofer give me problems? How does work change from 1 to 2?
Question 5: for the MID section, from the simulations in Hornresp (if correct), I should be able to get to 1KHz with 4", while if I use 3", always faital, I should get around 1.2KHz...what’s the best idea according to you?
The radian driver would not have problems in any case, but I think that if it is a sound quality level, it would be better to extend more the work of the MID, or let the CD do it...
I tested my hearing, and at 36 years old I stop around 16KHz...my girlfriend, 24 years old, arrives around 18KHz...
I don’t see the need to insert a driver from 1", I prefer to spend more for an excellent driver from 1.4"...
I have much to ask of you, and even more to learn, but for now I stop here...
As I advance with the project, I will write again...
Thank you all again 🙂
Following rickmcinnis-1965's advice, I've been studying Synergy horns, and I've decided to go that route.
In my opinion, there is something magical about the point source concept, applied as Danley thought of it.
The theory is simple, but I quickly realized that the success of the project relies on small modifications, as well as good design...
I've started playing with horn resp, and I'm beginning to understand it...I'm doing some simulations as an offset drive, the simulations in multiple entry I can't complete yet, but we'll talk about that later, for now I'd like to start by asking you for design advice.
Objectives: Synergy 3-way speaker, hifi destination, which will be completed with a sub, about from 80Hz down...
I'd like to be able to listen at low volumes, without background noise (I'll think about amplification later, which will be class D for the power amps anyway), and be able to get to 120dB at need.
Opening angle 70° horizontally (minimum), 50° vertically.
I simulated to begin with (with google sketchup) the SH50 model produced by Danley, after going to read many threads (many of them here on DiyAudio, thank you), I also read the patent published by Danley sound lab.
I quote “The lower driver is located at a position along the horn passage where the passage has a preselected cross-sectional area that is no greater than the area of a round cross-section with a CIRCONFERENCE equal to a wavelength at the upper end of the frequency.
Please tell me now, if what I have understood is correct...
Assuming a distance between the CD diaphragm and the horn throat of 3cm, and a crossover frequency at 1200Hz with the MID driver, we can calculate:
Speed of sound 331.2 m/s + 0.6 x temperature in °C (assume 20°) = 343.2m/s
wavelength 343.2/1200Hz = 28.6cm
The distance of the input holes, from the CD diaphragm, must be 28.6/4 = 7.15cm.
First question: at this distance, should the center of the hole be located, or should the hole start there, and continue outward from the horn?
Also, since several Synergy designs are rounded in the corners, should the hole still be as close to the edge as possible? Or is it better to create it a little more centrally, without touching the corner rounding?
According to the patent, now I have to calculate the radius of the circle having the full wavelength as circumference, so 28.6/3.14159/2 = 4.55cm
At this point, assuming a 1.4” CD, with throat area 3.6x3.6cm, and 3 cm distance from the aperture to the throat, the prototype would look like this:
As I understand it, this is the ideal ratio between the distance of the emission centers and the area of the horn where the wavelength can no longer put pressure on the walls, right?
And here, we bring in the mids.
The first thing I realized is that if we want to keep the horn walls straight and the ideal ratio, the opening angle will be decided by these 3 parameters:
CD output diameter, distance of the CD diaphragm from the throat, crossover frequency with the MID.
So, the frequency of crossing between MID and WF, will be decided by us, but we should correct it to adapt to the already set angle, always if we want to try to keep the ratio.
Changing the crossover frequency between DC and MID is not recommended, because we have more chances to play on the low side, than above...
The relationship, it is no longer ideal...
The circumference of the WL is close to the edge, but does not touch it for 0.7cm.
By moving to the crossover frequency at 390Hz, we lower this distance to about 0.4cm.
Question 2:
This small distance, can cause problems in charging the horn at crossover frequency? Or will the two drivers, MID and WF, by collaborating (and equalizing them) be able to reproduce a flat response anyway?
This trumpet has an output of 67x67 degrees, but it is not what I would like...
Let’s complicate things a little...
Let’s assume that we want to create a horn with 50Vx70H degrees, driver from 1.4, crossover MID at 1Khz, this is the start:
As you can see, if you keep the correct distance of 1/4 WL from the CD’s diaphragm, the circumference of the WL at 1Kh is no longer in symmetry, and it breaks off from the edge of the narrow side by about 2mm, while it exceeds the wall of the wide side by 1.1cm.
The same will of course happen for WF...
So? The air no longer puts pressure on the corners at this point, but maybe the insertion of the mids will create turbulence in the crossing zone?
If I insert the mediums, the horn will not load some frequencies, with the risk of finding me with holes that I would not be able to correct then with dsp...
Question 3: What is the best way in this case? Will the dsp solve these problems if the horn is built like the above figure?
Now, let’s get to my idea:
I would build a 3 way Synergy, size is not an issue, using 1xFaital 12FH510, 2/4xFaital 4FE35 (maybe even a 3") and Cd Radian 745Neo.
Question 3: Has anyone tried this CD? I have no way of hearing anything here in Northern Italy, so I must rely on the opinions of other fans...
What about the exit of the throat? It’s a 10°, but I haven’t seen many people talking about the exit anchors in the Synergy horns, unlike other horns...
Are there any better CDs as a feature? Or being a 50x70 trumpet, not one would be good?
Any inventions? Forward rephasing rings?
I’ve already simulated the woofer in Hornresp, with good results (if I didn’t make mistakes)...
I would insert it in the narrow side, so that we can approach it to get in the air inlet holes...
I should be able to get up to 120dB with a single woofer, and besides saving money, this would be useful because the positioning in my room would be more convenient, and I have some ideas for the final aesthetic...
I have read about projects that use only one woofer, but I don’t understand how this can work optimally without its "twin" on the other side...
I do not want to use the rear reflex charging, I would close the back...
Question 4: Will one woofer give me problems? How does work change from 1 to 2?
Question 5: for the MID section, from the simulations in Hornresp (if correct), I should be able to get to 1KHz with 4", while if I use 3", always faital, I should get around 1.2KHz...what’s the best idea according to you?
The radian driver would not have problems in any case, but I think that if it is a sound quality level, it would be better to extend more the work of the MID, or let the CD do it...
I tested my hearing, and at 36 years old I stop around 16KHz...my girlfriend, 24 years old, arrives around 18KHz...
I don’t see the need to insert a driver from 1", I prefer to spend more for an excellent driver from 1.4"...
I have much to ask of you, and even more to learn, but for now I stop here...
As I advance with the project, I will write again...
Thank you all again 🙂