After discussing a bit about this in an other thread concerning the bass horn, I would like to ask the question here:
What do you thing about building a medium horn with this driver http://www.phlaudio.com/datasheets/25_pdf/3860.pdf in a CEMENT
(don't laugh) horn?
I like that idea very much, because it is very difficult to find compression drivers that goes down to the 150hz region. And I believe a quite massive cement horn would be very stable in terms of sonic performances.
- What are your feelings about a cement horn?
- What do you think about the chossen driver? Has somebody an experience with PHL drivers?
Ave a nice day!
What do you thing about building a medium horn with this driver http://www.phlaudio.com/datasheets/25_pdf/3860.pdf in a CEMENT
(don't laugh) horn?I like that idea very much, because it is very difficult to find compression drivers that goes down to the 150hz region. And I believe a quite massive cement horn would be very stable in terms of sonic performances.
- What are your feelings about a cement horn?
- What do you think about the chossen driver? Has somebody an experience with PHL drivers?
Ave a nice day!
Very interesting idea indeed I'd say...
About the driver: do you need it to be 10"? ...the fs of 75 is just about too high IMO if you plan to play down to 150 Hz ...
if that dosn't bother you I can recomend JBL's 10" 2012H (promodel) --- you cant go wrong there...
another top choice (but not as loud!) is ScanSpeak's midwoofers (www.scan-speak.dk)
Good luck
Hobbes
About the driver: do you need it to be 10"? ...the fs of 75 is just about too high IMO if you plan to play down to 150 Hz ...
if that dosn't bother you I can recomend JBL's 10" 2012H (promodel) --- you cant go wrong there...
another top choice (but not as loud!) is ScanSpeak's midwoofers (www.scan-speak.dk)
Good luck
Hobbes
Ruben,
Go here and download the tractix calculator, as well as the 3 articles by Dr Bruce Edgar. The Show Horn article has an excellent explanation of how to specify the driver for the type of horn configuration you want.
Bruce's articles are great, and the horns built from them have alway's worked very close to the design. Erik's calculator works well too, and the 150Hz trax midbass is very nice (I've built them).
I'm currently (when class/exams are over) another trax mid horn, and am finalising the design for a 60Hz hypex midbass with an EVM15L in it. The timber is on my living room floor just waiting for the time to have it cut and finished.
Also look at the LeCleach concrete horns (unfortunate JMLC's homepage is gone) and Vincente's round laminate horns. Mine are similar, but tractrix, and the new ones will be finished on a lathe.
Nope. Depends on the parameters of the drive unit. 75Hz Fs will be too low if anything in a number of configurations.
There's a ton of info to be mined in Bruce Edgar's posts on AA in the High Eff speakers forum.
Go here and download the tractix calculator, as well as the 3 articles by Dr Bruce Edgar. The Show Horn article has an excellent explanation of how to specify the driver for the type of horn configuration you want.
Bruce's articles are great, and the horns built from them have alway's worked very close to the design. Erik's calculator works well too, and the 150Hz trax midbass is very nice (I've built them).
I'm currently (when class/exams are over) another trax mid horn, and am finalising the design for a 60Hz hypex midbass with an EVM15L in it. The timber is on my living room floor just waiting for the time to have it cut and finished.
Also look at the LeCleach concrete horns (unfortunate JMLC's homepage is gone) and Vincente's round laminate horns. Mine are similar, but tractrix, and the new ones will be finished on a lathe.
An externally hosted image should be here but it was not working when we last tested it.
HobbesJunior said:
Nope. Depends on the parameters of the drive unit. 75Hz Fs will be too low if anything in a number of configurations.
There's a ton of info to be mined in Bruce Edgar's posts on AA in the High Eff speakers forum.
No experience with PHL, but cement's an excellent medium for horn construction. Here's JML's horn calculator (which I recommend over Tractrix) and a page of examples, including his:
http://perso.club-internet.fr/ndaviden/pavillon/lecleach.htm#ancre68820
http://perso.club-internet.fr/ndaviden/pavillon/exemples/exemples.html
GM
http://perso.club-internet.fr/ndaviden/pavillon/lecleach.htm#ancre68820
http://perso.club-internet.fr/ndaviden/pavillon/exemples/exemples.html
GM
Concrete designs
I remember a concrete bass horn and matching upper range horn design in Wirless World magazine from the 70's. If someone has access to pre 1975 issues you will find it.
A friend built one but I don't remember how good it was. We didn't have much to compare with at the time.
Might be interesting to go over the article again. Unfortunately I don't have a copy.
Cheers,
Ashok.
I remember a concrete bass horn and matching upper range horn design in Wirless World magazine from the 70's. If someone has access to pre 1975 issues you will find it.
A friend built one but I don't remember how good it was. We didn't have much to compare with at the time.
Might be interesting to go over the article again. Unfortunately I don't have a copy.
Cheers,
Ashok.
compression chamber?
Many thanks for your replies!
Do you think I would need a compression chamber for such an horn? I've seen some front horns without any compression chamber, so I don't really know what would be the best solution to do it...
I'm now thinking about the way to use the cement and to build it.
mmmhhh.
Have a nice day!
Many thanks for your replies!
Do you think I would need a compression chamber for such an horn? I've seen some front horns without any compression chamber, so I don't really know what would be the best solution to do it...
I'm now thinking about the way to use the cement and to build it.
mmmhhh.
Have a nice day!
http://www.users.bigpond.com/dmcbean/
try hornresp.
front chamber acts as a filter varying top end.
adrians 150hz tractix. http://www.geocities.com/adrian_mack/tractrix.html
try hornresp.
front chamber acts as a filter varying top end.
adrians 150hz tractix. http://www.geocities.com/adrian_mack/tractrix.html
GM said:
Hi GM,
Could you please comment more on this? Why do you prefer one over the other?
I've been intrigued by the LeCleac'h flares for some time, but haven't the practical experience of implementation that I do with trax, and there is no simulator like the McBean that I'm aware of.
For example, as I mention above, I'm soon to make some sawdust for a set of laminated trax flares. These will be 280Hz Fc, aiming for a good 400Hz response with my BMS 2"compression drivers. From previous attempts, I know they'll work as expected, but without making several using JML's model I'm not sure where the compromises / tweaks should be.
Any help in shortening the learning curve would be appreaciated.
Brett said:
The following gentleman sells LeCleach style concrete horns and would probably be willing to work with you to customize them to your chosen drivers. They're not cheap and shipping to the US makes them even more expensive, but for our European friends they might be a possibility.
http://site.voila.fr/musique_concrete
---Gary
"What are your feelings about a cement horn?"
Don't get horns and boxes confused. The air pressure acting against a horn is relatively small compared to the pressure working against the sides of a sealed box. My guess is well damped plastic or wood would be better and a whole lot more mobile.
John
Don't get horns and boxes confused. The air pressure acting against a horn is relatively small compared to the pressure working against the sides of a sealed box. My guess is well damped plastic or wood would be better and a whole lot more mobile.
John
Brett said:
Well I build quite a bit of my own stuff but I know my limits. Building tractrix or other geometry horns is beyond me - I'd rather focus on building the electronics and turntables. I let Bruce Edgar build my horns for me - his prices on unfinished horns is actually pretty reasonable for those of us in the states. The only drawback is that his lead time can be very long.
---Gary
>Hi GM,
Could you please comment more on this? Why do you prefer one over the other?
====
Morning,
A tractrix termination is at 180deg, so for wave launch purposes we can view it as flat baffle with a 'driver' dead center, and we know from Olson's work how this affects the FR. JML's approach is to round over the 'baffle' to come closer to the spherical ideal.
As for the tractrix flare itself, due to it being a truncated hyperbolic it 'shades' the HF a bit too much for my tastes, making for too narrow a 'sweet spot'.
====
>I've been intrigued by the LeCleac'h flares for some time, but haven't the practical experience of implementation that I do with trax, and there is no simulator like the McBean that I'm aware of.
====
While JMLC's plots a theoretically 'best' compromise, if you're happy with the tractrix flare, then just rolling over the mouth termination works just as it would by adding a large round over to a flat baffle.
GM
Could you please comment more on this? Why do you prefer one over the other?
====
Morning,
A tractrix termination is at 180deg, so for wave launch purposes we can view it as flat baffle with a 'driver' dead center, and we know from Olson's work how this affects the FR. JML's approach is to round over the 'baffle' to come closer to the spherical ideal.
As for the tractrix flare itself, due to it being a truncated hyperbolic it 'shades' the HF a bit too much for my tastes, making for too narrow a 'sweet spot'.
====
>I've been intrigued by the LeCleac'h flares for some time, but haven't the practical experience of implementation that I do with trax, and there is no simulator like the McBean that I'm aware of.
====
While JMLC's plots a theoretically 'best' compromise, if you're happy with the tractrix flare, then just rolling over the mouth termination works just as it would by adding a large round over to a flat baffle.
GM
>Do you think I would need a compression chamber for such an horn? I've seen some front horns without any compression chamber, so I don't really know what would be the best solution to do it...
====
For max performance, the horn would have to be designed based on a dipole configuration. Making it aperiodic, or in an extreme case removing the back chamber altogether, is what you resort to when there's too much gain in the design for the application.
GM
====
For max performance, the horn would have to be designed based on a dipole configuration. Making it aperiodic, or in an extreme case removing the back chamber altogether, is what you resort to when there's too much gain in the design for the application.
GM
The other option!
After a long time thinking about it, I finally changed my mind.
I'm building both a medium horn (900-20'000 Hz) and very soon a low-medium (200-900 Hz) horn with epoxy and fiber glas.
To do it, I'm using a kind of pottery lathe (diy) to make a hard matrix. Now, I'm currently putting the epoxy and fiber glas on it.
Some pictures of the matrix building process :
Voilà!
Have a good day!
Ruben.
After a long time thinking about it, I finally changed my mind.
I'm building both a medium horn (900-20'000 Hz) and very soon a low-medium (200-900 Hz) horn with epoxy and fiber glas.
To do it, I'm using a kind of pottery lathe (diy) to make a hard matrix. Now, I'm currently putting the epoxy and fiber glas on it.
Some pictures of the matrix building process :
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Voilà!
Have a good day!
Ruben.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.