Here is a variant based on 250Hz but the loading should be lesser because of the increasing T factor. Should be better usable on top of a bass cabinet.
View attachment drba_250hz_pe.zip
I like that shape! Unfortunately, 3D print service automatically linked to my viewer said its too large to print and warned about thin walls 🙂
...the same as just shown but with a little portion of stereograhic projection applied.
View attachment drba_250hz_pe_sp.zip
View attachment drba_250hz_pe_sp.zip
Thank you Docali, first of all. You are being generous by giving me your time. I was told that you would be the person to contact. First you should know that this is a work in progress so... my natural inclination was to suggest tractrix, since a tractrix results in a smaller opening. The 110hz tractrix on auto tech at 39" diameter is about as big as I would want to go.
I am confused about the loading of the 120hz and 250hz file you send, is that the Fc or not? Can you gen a file for a tractrix that complies with " Salmon horn with 0<=T<1 "? I don't know what diameter that would create but if loading is mainly governed by throat length then I aiming for around 33.5in/91.44cm throat length, that would put me at generally 1/2WL of 200hz. A JMLC might work as long as diameter isnt too big.
What are you guys using to view these files btw?
I am confused about the loading of the 120hz and 250hz file you send, is that the Fc or not? Can you gen a file for a tractrix that complies with " Salmon horn with 0<=T<1 "? I don't know what diameter that would create but if loading is mainly governed by throat length then I aiming for around 33.5in/91.44cm throat length, that would put me at generally 1/2WL of 200hz. A JMLC might work as long as diameter isnt too big.
What are you guys using to view these files btw?
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You can use the windows 3D viewer or Meshlab or any other that can open ply files. ply is a different format like stl.
A tractrix like this from Autotech would beam terribly. The cut-off in my examples only hold for horns with constant T factor. So, the examples should have less loading capabilities. You can roughly consider the length of the horn and do a quarter-wave or half-wave guess.
The first question for me is what driver you want to use and how far you want go down for the cross-over frequency. Even for my 18s 4015Be I would not go much below 650 Hz as cross-over point with an appropriate horn. My 400Hz Tractrix already beams quite much but sounds natural. The best compromise so far is a Selenium 40x20 horn.
If you leave the T factor constant you get a quite long horn but with slightly more beaming. This is why I introduced an algorithm for a constantly increasing T factor.
So, you should a little more precise what you want to use for your setup.
OK and thank you for working with me.
The driver is an Celestion Axi2050, 2" exit.
xover desire is 200hz
Beaming is acceptable
Your input is welcome...you say that your unique T factor adjustment makes for less beaming yet the half wavelength intended is 34" so I imagine that the opening would be larger. What is that number? I may sacrifice size in order to gain performance. A tractrix horn would lessen the opening diameter.
Celestion Axi2050 - 2" Compression Driver
Looking at the PWT I believe that with the proper horn this driver can play even lower than 200hz. 200hz xover is my goal... but 150hz xover putting me at -1db at 200hz in the horn... would make me cry tears of joy. The group delay of this driver on a 250hz classic JMLC seems to comply...in the measurements it seems that the driver falls off right at 250hz. I am also believing that group delay will improve with a larger horn, for the passband. The TD15M is under 1ms above 150hz.
So I hope that answers your questions, thank you so much for lending you time! The first jmlc you sent (160hz) what are its dimensions?
The driver is an Celestion Axi2050, 2" exit.
xover desire is 200hz
Beaming is acceptable
Your input is welcome...you say that your unique T factor adjustment makes for less beaming yet the half wavelength intended is 34" so I imagine that the opening would be larger. What is that number? I may sacrifice size in order to gain performance. A tractrix horn would lessen the opening diameter.
Celestion Axi2050 - 2" Compression Driver
Looking at the PWT I believe that with the proper horn this driver can play even lower than 200hz. 200hz xover is my goal... but 150hz xover putting me at -1db at 200hz in the horn... would make me cry tears of joy. The group delay of this driver on a 250hz classic JMLC seems to comply...in the measurements it seems that the driver falls off right at 250hz. I am also believing that group delay will improve with a larger horn, for the passband. The TD15M is under 1ms above 150hz.
So I hope that answers your questions, thank you so much for lending you time! The first jmlc you sent (160hz) what are its dimensions?
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Once you've extracted the .rar, right click on the "drba_250hz_pe_sp" 3D-object file (.ply) and choose "open with" > 3D-viewer.
The attachment is in Dutch, but you'll get it.
This only works on Windows 10, if you're still on 7 you can use an online 3D viewer, or download meshlab.
The attachment is in Dutch, but you'll get it.
This only works on Windows 10, if you're still on 7 you can use an online 3D viewer, or download meshlab.
Attachments
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While searching for data of some Emilar horns, I came across POOH's midbass horns. These are Emilar EH153Hs, which were originally supplied with Emilar's EC600 low-mid compression drivers (6" diaphragms).
More on this later.
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@camplo
I would not choose such a low x-over point. A plane wave is completely different thing compared to a practically usable horn.
You could ask Autotech if they can make a tractrix for you with 2" exit. But this will be also become very long! Spherical wave horn and JMLC both have a larger diameter compared to tractrix but they are shorter. The progressive expansion T factor causes a faster opening thus leading to potentially less beaming. But the drawback should be less loading capabilities.
I can only provide 3D files like ply and stl. You will probably not find a 3D printer for such a large horn. Another source than come to my mind is Azurahorn. He seems to have some molds down to 160Hz.
I would not choose such a low x-over point. A plane wave is completely different thing compared to a practically usable horn.
You could ask Autotech if they can make a tractrix for you with 2" exit. But this will be also become very long! Spherical wave horn and JMLC both have a larger diameter compared to tractrix but they are shorter. The progressive expansion T factor causes a faster opening thus leading to potentially less beaming. But the drawback should be less loading capabilities.
I can only provide 3D files like ply and stl. You will probably not find a 3D printer for such a large horn. Another source than come to my mind is Azurahorn. He seems to have some molds down to 160Hz.
Hallo
The french designer (whats his name Ro808) made the same comment about assumptions of capabilities based off PWT. So though it may not work, it has not been proven to not work. So I will try, and if I have to settle for a higher xover, then so be it. The autotech 110hz tractrix is 66cm long with 4" exit...to get to 2" exit, if it was between 76cm and 100cm I could make it work.
I think 150hz loading is a good starting point for me.
Can you do a model for a tractrix and Jmlc at 150hz with the desired T expansion factor?
I am building my own horns so I need to be able to create a profile and as well we are using your 3d files to see what is possible with a mini CNC. Thank you.
Dredging this back up. These drivers (and the 6" versions) are still available. What are the odds that they are legitimate, first quality Tannoy drivers, not QC rejects that found their way out the back door, or outright fakes? The same seller has "B&W" tweeters for sale that are clearly marked as "Clones". Returns are not accepted, of course.
If they are legit, I'd be sorely tempted to try the 8 inchers.
Bill
Hi
I used black mat camouflage paint. They disappear visually even when I have on the projector in the dark room. The original white was like sitting between two bathtubs. 🙂 annoying
Midbass is Emilar horn with floor/sidewall placed with B&C 8".
I also use the EV big 60 degree horns with JBL 2450SL.. both sound very good.
Crossover is 500 Hz - upper range driver is Radian 835 1.4" with BE
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Amazing what a little searching can turn up:
2 unit pair Tannoy revolution XT6 6.5 inch coaxial speaker woofer fullrange unit-in Bookshelf Speakers from Consumer Electronics on AliExpress - 11.11_Double 11_Singles' Day
"you are purchase pair Tannoy revolution XT6 6.5/7inch coaxial speaker unit
6.5 paper cone+25MM Ti dome tweeter..coaxial speaker
98% new as photo show.new old stock never been use"
Half the price of the ones on ebay.
At least these don't claim to be real, they just 'reference Tannoy':
pair 2pcs Melo David davidlouis audio HIEND 6.5 inch coaxial speaker fullrange woofer-in Bookshelf Speakers from Consumer Electronics on AliExpress - 11.11_Double 11_Singles' Day
2 unit pair Tannoy revolution XT6 6.5 inch coaxial speaker woofer fullrange unit-in Bookshelf Speakers from Consumer Electronics on AliExpress - 11.11_Double 11_Singles' Day
"you are purchase pair Tannoy revolution XT6 6.5/7inch coaxial speaker unit
6.5 paper cone+25MM Ti dome tweeter..coaxial speaker
98% new as photo show.new old stock never been use"
Half the price of the ones on ebay.
At least these don't claim to be real, they just 'reference Tannoy':
pair 2pcs Melo David davidlouis audio HIEND 6.5 inch coaxial speaker fullrange woofer-in Bookshelf Speakers from Consumer Electronics on AliExpress - 11.11_Double 11_Singles' Day
No he was talking about the PWT results from the axi....Bjorn something...
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Bjorn Kolbrek? He works for Celestion and designed their two horns for the Axi2050 shown just up thread. They are very nice but also very expensive and don't go that low.
He is also co-author of the book on horns that has just come out. Also expensive at around £130 I believe.
He is also co-author of the book on horns that has just come out. Also expensive at around £130 I believe.
So I need a way to be able to calculate the horn profile without bothering people to do it for me. I downloaded Ath4 and Abec/Vacview demo.....have no idea how to use it yet.
Once I figure out how to design the horn profile and get the dimensions squared away I will build a figure like in the picture out of wood rings... and then use a 2d profile to sculpt the inside of the horn, using some type of molding material
The second idea, is to get the a 3d model of the horn and chop it up into pieces a mini cnc can machine and then assemble. Then theres the already tried a proved methods of round horn building as well.
This horn SPHERICAL-185 - Horns by Auto-Tech has the right specs and dimensions so I know I'm on the right track. I'm not sure about spherical but it seems that JMLC is more popular and tractrix would give a smaller opening, but like I said, I am not sure how spherical fits into the group as far as sound quality and what people prefer.
or option C, I'll just settle for the biggest tractrix my guy can ship me, and buy that and cross at 300hz...lol
Once I figure out how to design the horn profile and get the dimensions squared away I will build a figure like in the picture out of wood rings... and then use a 2d profile to sculpt the inside of the horn, using some type of molding material
The second idea, is to get the a 3d model of the horn and chop it up into pieces a mini cnc can machine and then assemble. Then theres the already tried a proved methods of round horn building as well.
This horn SPHERICAL-185 - Horns by Auto-Tech has the right specs and dimensions so I know I'm on the right track. I'm not sure about spherical but it seems that JMLC is more popular and tractrix would give a smaller opening, but like I said, I am not sure how spherical fits into the group as far as sound quality and what people prefer.
or option C, I'll just settle for the biggest tractrix my guy can ship me, and buy that and cross at 300hz...lol
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