Wow these are long livin' -
Here is an even more detailed page about the Schmacks horn mentioned, with very beautiful 3D pix if you click the picture.
Exponentialhorn nach Schmacks
What you think - should I dig it up from the attic and what driver to try as a bass horn only ?
Michael
Here is an even more detailed page about the Schmacks horn mentioned, with very beautiful 3D pix if you click the picture.
Exponentialhorn nach Schmacks
What you think - should I dig it up from the attic and what driver to try as a bass horn only ?
Michael
Have forgotten completely about that in the meantime, as all my horn projects back then didn't turn out that well and I also never was interested in band pass sub's...
######
What's your take on different contours for bass horns – I mean - we are not so much after "diffraction alignment" or "directivity control" or "sound field uniformity" in the room mode department, or are we ?
From your experience – is there a major sonic difference in contours?
And also – as those bass horns are big monsters – what is the sonic impacts of folding bass horns – is there something one could say "in general"?
By the way here is a measurement taken for the above (exponential) Schmacks bass horn – the lower trace is taken directly in front of the driver - the ~ 6dB higher trace is taken directly in front of the horn mouth:
AUDIO-VIDEO FORUM :: Thema anzeigen - SCHMACKSHORN- für dich Jürgen!
Look at the top left plot on this link (schmacks_2_5.jpg):
http://www.audiovideoforum.de/userpix/schmacks_2_5.jpg
The interesting thing here is that the author claims to having tried out a bunch of 25 (!) chassis (Qts range between 0,16 - 0.45 / 28 - 35Hz / Vas 21 - 50 liter) in that horn and they all measured basically the same .
This one is fairly cheap :
http://www.wavecor.com/html/sw178wa01.html
possibly could work ...
Michael
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Hello,
That's quite interesting, here is the measurement at 0.36 meter from the mouth of a rare Onken 455 mounted on Martin Seddon's AH425 horn:
http://i102.photobucket.com/albums/m83/jonjinkim/Onken bass cabs/Mid68F.jpg
Flat on axis as ever with the Le Cléac'h horn.
For other informations (BTW I am not related not the seller), see :
eBay.be: Onken OM-455ES (500MT) mid driver TAD ALE GOTO Vitavox (objet 260566311056 Fin: 20-mars-10 14:14:27 CET)
Best regards from Paris, France
Jean-Michel Le Cléac'h
That's quite interesting, here is the measurement at 0.36 meter from the mouth of a rare Onken 455 mounted on Martin Seddon's AH425 horn:
http://i102.photobucket.com/albums/m83/jonjinkim/Onken bass cabs/Mid68F.jpg
Flat on axis as ever with the Le Cléac'h horn.
For other informations (BTW I am not related not the seller), see :
eBay.be: Onken OM-455ES (500MT) mid driver TAD ALE GOTO Vitavox (objet 260566311056 Fin: 20-mars-10 14:14:27 CET)
Best regards from Paris, France
Jean-Michel Le Cléac'h
Link to design calculator?
I have read the whole thread and remember seeing a link to the design calculator but can't seem to find it again using the search. Can some one post the link. I would like to try these horns.
Second question. How much trade off in the highs is there between using a T=.8, 350Hz horn versus a T=.8, 400Hz with the 1 inch Radian475 driver, which is said to have an FS of 535 on a 350 horn and usable output to 550, crossed at 700Hz. The 350 horn will have a slightly steeper and earlier down tilt in the highs as you move off axis?
I have read the whole thread and remember seeing a link to the design calculator but can't seem to find it again using the search. Can some one post the link. I would like to try these horns.
Second question. How much trade off in the highs is there between using a T=.8, 350Hz horn versus a T=.8, 400Hz with the 1 inch Radian475 driver, which is said to have an FS of 535 on a 350 horn and usable output to 550, crossed at 700Hz. The 350 horn will have a slightly steeper and earlier down tilt in the highs as you move off axis?
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Hello Soongsc,
Do you read Japanese fluently? (I could be interested in few translations).
The final tuning of every Onken Drivers was made by Koizumi San himself in his small workshop. He did pairs of drivers, one for left ear and the other one for right ear (for what it seems Japanese people don't hear the same by left and right ear).
I own a pair of Onken tweeters OS5000T and one tweeter is written "left" and the other is written "right".
Best regards from Paris, France
Jean-Michel Le Cléac'h
Do you read Japanese fluently? (I could be interested in few translations).
The final tuning of every Onken Drivers was made by Koizumi San himself in his small workshop. He did pairs of drivers, one for left ear and the other one for right ear (for what it seems Japanese people don't hear the same by left and right ear).
I own a pair of Onken tweeters OS5000T and one tweeter is written "left" and the other is written "right".
Best regards from Paris, France
Jean-Michel Le Cléac'h
Those were Chinese characters to me. I have no idea how to read Japanese, but my daughter is learning some.
Actually, my left and right ear each have a different response. I believe this is common to most people. It seems the right ear normally has better high frequency sensitivity. I'll check with the hearing aid company to see if they notice a trend or not.
Hello Sendler,
If you plan to build an axisymetric horn, then you can use Hornresp from which you can export the profile.
If you send me an email with your electronic adress l'll send you the last version of the spreadsheet.
IMHO there will be nearly no audible difference between the horn having the Fc of 350Hz and the one having an Fc of 400Hz.
Here is my email adress
jean-michel.le_cleachXmines-paristech.fr
(replace the X by the arobase)
Best regards from Paris, France
If you plan to build an axisymetric horn, then you can use Hornresp from which you can export the profile.
If you send me an email with your electronic adress l'll send you the last version of the spreadsheet.
IMHO there will be nearly no audible difference between the horn having the Fc of 350Hz and the one having an Fc of 400Hz.
Here is my email adress
jean-michel.le_cleachXmines-paristech.fr
(replace the X by the arobase)
Best regards from Paris, France
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Hello Soogsc,
You'll find in attached files, the 2 pages notice I received from Onken with my OS5000T tweeters.
Best regards from Paris, France
Jean-Michel Le Cléac'h
You'll find in attached files, the 2 pages notice I received from Onken with my OS5000T tweeters.
Best regards from Paris, France
Jean-Michel Le Cléac'h
Attachments
The only thing I can make of those pages for now are as follows:
1. The title of the first page says "Things to consider carefully". What we need to be careful about? I have no idea.
2. The second page seems to talk about the chemical treatment conducted on these drivers, and the performance of the drivers.
Basically, there are many characters adopted from the Chinese language, and carry approximately the same meaning. The more simple looking characters are Japanese.
Hello Soongsc,
Thanks for those informations.
Best regards from Paris, France
Jean-Michel Le Cléac'h
Thanks for those informations.
Best regards from Paris, France
Jean-Michel Le Cléac'h
1. The title of the first page says "Things to consider carefully". What we need to be careful about? I have no idea.
2. The second page seems to talk about the chemical treatment conducted on these drivers, and the performance of the drivers.
400Hz vs. 800 horn?
.
Same question for 1 inch versus 1.4 inch versus 2 inch compression drivers on the same 350HZ horn which has been cut to accept their exits flush? Do the off axis polars change for the different throat diameters on the otherwise same horn?
Perhaps my question would have been better with horns that were more different. How much trade off in the highs is there between using a T=.8, 350Hz horn versus a T=.8, 800Hz crossed at 1600Hz. Will the 350 horn will have a slightly steeper and earlier down tilt in the highs as you move off axis? Or is there no difference to the off axis curves so we should always just use the biggest horn that we can fit through the door for our tweeters?
.
Same question for 1 inch versus 1.4 inch versus 2 inch compression drivers on the same 350HZ horn which has been cut to accept their exits flush? Do the off axis polars change for the different throat diameters on the otherwise same horn?
Hello,
The numerous measurements I have made on different Le Cléac'h horns have shown that mounted on the same TD2001, a Le Cléac'h horn having an Fc of 320Hz possess a more extended frequency response in the high frequencies than (e.g.) a Le Cléac'h horn having an Fc of 1200Hz. (That's strange but true and probably due to the small throat angle of a 320Hz horn compared to a 1200Hz horn).
Then mounted on the same driver the directivity of the Fc = 1200Hz horn is smaller than the directivity of the Fc = 320Hz.
There is not a huge difference in the way the directvity of a Le Cléac'h horn having an Fc around 400Hz (e.g.) varies with frequency compared to a cone loudspeaker of 8" diameter (roughly).
It is quite easy to match directivity at the crossover frequencies between a 12 to 15" bass/mid loudspeaker and a Le Cléac'h horn if you correctly choose the driver and the cut-off.
But you have to know that I listen on-axis and I don't care about off-axis radiation.... ;-)
Best regards from Paris, France
Jean-Michel Le Cléac'h
The numerous measurements I have made on different Le Cléac'h horns have shown that mounted on the same TD2001, a Le Cléac'h horn having an Fc of 320Hz possess a more extended frequency response in the high frequencies than (e.g.) a Le Cléac'h horn having an Fc of 1200Hz. (That's strange but true and probably due to the small throat angle of a 320Hz horn compared to a 1200Hz horn).
Then mounted on the same driver the directivity of the Fc = 1200Hz horn is smaller than the directivity of the Fc = 320Hz.
There is not a huge difference in the way the directvity of a Le Cléac'h horn having an Fc around 400Hz (e.g.) varies with frequency compared to a cone loudspeaker of 8" diameter (roughly).
It is quite easy to match directivity at the crossover frequencies between a 12 to 15" bass/mid loudspeaker and a Le Cléac'h horn if you correctly choose the driver and the cut-off.
But you have to know that I listen on-axis and I don't care about off-axis radiation.... ;-)
Best regards from Paris, France
Jean-Michel Le Cléac'h
Very fascinating
Very fascinating and counter intuitive to the reports of 400Hz tractrix horns I have read but your first hand experience and timely replies are greatly appreciated by all. Now I am not afraid to buy the 350Hz horn even if my driver ends up crossing at 900-1000Hz. The 350 does have a large and dominating appearance though. 60cm wide.
Very fascinating and counter intuitive to the reports of 400Hz tractrix horns I have read but your first hand experience and timely replies are greatly appreciated by all. Now I am not afraid to buy the 350Hz horn even if my driver ends up crossing at 900-1000Hz. The 350 does have a large and dominating appearance though. 60cm wide.
5 degrees
I see that my 400Hz, T.8, 1 inch horn design is averaging 5 degrees from axis in the first 10mm. Earlier in the thread I saw data stating that many 1 inch drivers have 14 degree exits. Is this measured 14 degrees on each side from axis or 14 degrees total included angle/ 7 degrees from axis. Would it be better to design the horn so that the 1 inch inner diameter occurred at a point down the length of the curve where the slope was matching or is 5 degrees close enough? I have written to Radian to ask if they know what the exit angles of their drivers are but they haven't written me back yet.
I see that my 400Hz, T.8, 1 inch horn design is averaging 5 degrees from axis in the first 10mm. Earlier in the thread I saw data stating that many 1 inch drivers have 14 degree exits. Is this measured 14 degrees on each side from axis or 14 degrees total included angle/ 7 degrees from axis. Would it be better to design the horn so that the 1 inch inner diameter occurred at a point down the length of the curve where the slope was matching or is 5 degrees close enough? I have written to Radian to ask if they know what the exit angles of their drivers are but they haven't written me back yet.
I don't know about the small-format Radians, but the 1.4" exit 745P is 4 degrees, while the Altec & GPA 288 are 8 degrees. That is overall divergence between both walls, not just one.
As you might imagine, it is more acceptable to have a slightly diverging compression driver go into a horn with a larger divergence than the other way around - regions of "pinch-downs" create very strong reflections. If the Radian is similar to its larger brothers, your horn should work fine. The response will require little or no equalization.
In terms of contacting Radian, I had better luck with phone calls - and asking to speak to an application engineer - than e-mail. Keep your questions short, direct, and technical, avoid vague audiophile subjective questions, and you'll do fine. If you do contact them, we'd all like to know what the exit angle for the small-format drivers are - please post it here.
So far, my list of exit angles is looking like this:
Altec & GPA:
288 = 8°
Radian:
745P = 4°
18sound:
NSD1095N, ND1090 = 27°
NSD1480N = 10°
Beyma
CP750Nd – 24º
CP850Nd – 7º
CP755Nd – 12º60’
SMC65Nd – 15º
CP385Nd – 16º30’
SMC225Nd – 13º1’
B&C
1"
DE250 14.6°
DE10 7.7°
DE12 24°
DE400TN 20.7°
DE400 31°
DE500 17°
DE200 9.9°
2"
DE85TN 34.5°
DE750TN 22°
DE950TN 17°
As you might imagine, it is more acceptable to have a slightly diverging compression driver go into a horn with a larger divergence than the other way around - regions of "pinch-downs" create very strong reflections. If the Radian is similar to its larger brothers, your horn should work fine. The response will require little or no equalization.
In terms of contacting Radian, I had better luck with phone calls - and asking to speak to an application engineer - than e-mail. Keep your questions short, direct, and technical, avoid vague audiophile subjective questions, and you'll do fine. If you do contact them, we'd all like to know what the exit angle for the small-format drivers are - please post it here.
So far, my list of exit angles is looking like this:
Altec & GPA:
288 = 8°
Radian:
745P = 4°
18sound:
NSD1095N, ND1090 = 27°
NSD1480N = 10°
Beyma
CP750Nd – 24º
CP850Nd – 7º
CP755Nd – 12º60’
SMC65Nd – 15º
CP385Nd – 16º30’
SMC225Nd – 13º1’
B&C
1"
DE250 14.6°
DE10 7.7°
DE12 24°
DE400TN 20.7°
DE400 31°
DE500 17°
DE200 9.9°
2"
DE85TN 34.5°
DE750TN 22°
DE950TN 17°
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Those exit angles are hard to get info and of high value
I tried once, with one Beyma driver
It took a while
At first they had no idea what I was asking
I did manage to get the info, after one week, and several mails
Why the wide range of exit angles ? I suppose it has to do with different "phase plug" compression designs
But do they ALL take the phase plug into account when calculating exit angle ?
Maybe not, which could explain the huge differences
I tried once, with one Beyma driver
It took a while
At first they had no idea what I was asking
I did manage to get the info, after one week, and several mails
Why the wide range of exit angles ? I suppose it has to do with different "phase plug" compression designs
But do they ALL take the phase plug into account when calculating exit angle ?
Maybe not, which could explain the huge differences
You can see from the wide variation of exit angles why mixing-n-matching horns and drivers gives unpredictable results. It's bad enough when the driver and horn are significantly different - reflections right where you don't want them - and worst of all when the driver has a wide exit angle going into a narrower-profile horn.
This kind of pinching-down makes big problems with reflections in the time domain, screws up diaphragm loading at certain frequencies, and causes ripples in the frequency response. All of the design work on the phase plug to create a plane wavefront is wasted when the first thing it sees is a massive reflection before it even gets into the horn. Don't forget that simple misalignment (off-center or a non-circular entrance to the horn) creates many of the same problems.
The most recent LeCleac'h spreadsheet has the option to enter the value of the exit angle of the driver, but you're out of luck with the old-school horns - the exit angle might not have even have been a design consideration. I don't know about OS, quadratic throat, and conical horns - there should be a parameter where this can be entered in and allowed for.
This kind of pinching-down makes big problems with reflections in the time domain, screws up diaphragm loading at certain frequencies, and causes ripples in the frequency response. All of the design work on the phase plug to create a plane wavefront is wasted when the first thing it sees is a massive reflection before it even gets into the horn. Don't forget that simple misalignment (off-center or a non-circular entrance to the horn) creates many of the same problems.
The most recent LeCleac'h spreadsheet has the option to enter the value of the exit angle of the driver, but you're out of luck with the old-school horns - the exit angle might not have even have been a design consideration. I don't know about OS, quadratic throat, and conical horns - there should be a parameter where this can be entered in and allowed for.
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