A build thread for my soon to arrive Radian 850pb's.
Souce Mac - Active XO with minidSP 2x8 - 8 Channel Rotel 1048
This is the initial idea. I have a pair of Beyma 10BR60's on the way to cover the lower end.
I'm hoping to build some wooden 400Hz conical horns & JMLC.
And if needed a OSWG or JMLC to mate with a BMS 4538 for top end.
Will update when work starts.
Souce Mac - Active XO with minidSP 2x8 - 8 Channel Rotel 1048
This is the initial idea. I have a pair of Beyma 10BR60's on the way to cover the lower end.
An externally hosted image should be here but it was not working when we last tested it.
I'm hoping to build some wooden 400Hz conical horns & JMLC.
And if needed a OSWG or JMLC to mate with a BMS 4538 for top end.
Will update when work starts.
Very interested tio see how you will build the horns. I have often thought of doing a similar system with 400hz horns but with a 416-MLTL or maybe even RCA-fans (Bill Woods) half horn with altec 515. Please post lots of pics.
Old thread
MDF mockup, have some engineered walnut on the way and a better plan for production.
MDF mockup, have some engineered walnut on the way and a better plan for production.
An externally hosted image should be here but it was not working when we last tested it.
given this is a two way it would have been nice to align the horn and woofers. any chance of doing that? It would require a whole new visual from the picture you have posted here (which I think looks very nice by the way) just not aligned. Looking forward to seeing what ever you build. Best regards Moray James.
lining up the woofers and the compression driver's diaphragms, but I do realize that doing so makes for a strange set of visuals. Having played with the alignment of a two way in this fashion (aligning the centre of the drivers top plates) had such a marked effect that to do otherwise for me now is not an option. Best regards Moray James.
Ah yeah, well the JMLC horn at 350Hz is only 300mm or so deep, the conical is slightly larger.
Model isn't accurate, just a quick visualisation of the sort of thing i am aiming for.
Correction can be made digitally with the XO possibly?
Model isn't accurate, just a quick visualisation of the sort of thing i am aiming for.
Correction can be made digitally with the XO possibly?
Strange set of visuals
Hi Moray,
Please forgive the picture quality. This is as close as I could get to a v.c. line up. This is a Sierra-Brooks 32inch diameter tractrix loaded with EV-DH1506
There was a previous attempt at sanding down parts of the horn's finish, and based on the performance outcome, the horns will be re-finished in auto-grade paint. Thus far, after only two nights audition, the results are actually very, very good. Having said that, I can hear the crossover point because the Altec 416-8B's are just direct radiators at the time. My previous mid-bass, short (stub) horns were a better match with regards to acoustic wavelaunch. The reason I didn't use them here, in this application, is: this requires clean flat response up to meet the 500hz crossover point, whereas before the required point was only 250Hz, and the ppsl's start to sound "garbled" up that high. If I do another ppsl driven mid-bass horn, I will re-build the manifold with angled mount boards as well as wavelaunch boards.
The "attack" by the double Eminence 4012's is not duplicated by the Altecs, although the "sustain" and "tone quality" is somewhat improved. If I had another pair of 416-8B's, I'd be very attempted in doing a ppsl horn/hybrid for those as well. The clean and powerful "attack" of a ppsl (reaction-canceling)
simply can not be duplicated by a conventional mount driver.
NOTE: the "odd visual look" A mid-bass horn would look more appropriate.
best regards to all, and happy listening !
Hi Moray,
Please forgive the picture quality. This is as close as I could get to a v.c. line up. This is a Sierra-Brooks 32inch diameter tractrix loaded with EV-DH1506
There was a previous attempt at sanding down parts of the horn's finish, and based on the performance outcome, the horns will be re-finished in auto-grade paint. Thus far, after only two nights audition, the results are actually very, very good. Having said that, I can hear the crossover point because the Altec 416-8B's are just direct radiators at the time. My previous mid-bass, short (stub) horns were a better match with regards to acoustic wavelaunch. The reason I didn't use them here, in this application, is: this requires clean flat response up to meet the 500hz crossover point, whereas before the required point was only 250Hz, and the ppsl's start to sound "garbled" up that high. If I do another ppsl driven mid-bass horn, I will re-build the manifold with angled mount boards as well as wavelaunch boards.
The "attack" by the double Eminence 4012's is not duplicated by the Altecs, although the "sustain" and "tone quality" is somewhat improved. If I had another pair of 416-8B's, I'd be very attempted in doing a ppsl horn/hybrid for those as well. The clean and powerful "attack" of a ppsl (reaction-canceling)
simply can not be duplicated by a conventional mount driver.
NOTE: the "odd visual look" A mid-bass horn would look more appropriate.
best regards to all, and happy listening !
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Why does he have to align the compression driver and woofers if he plans to use DSP? He can just delay the woofer with DSP and keep things the way he has them. If he wants to go passive there is still the option to use something like the Quasi-optimal crossover which uses the natural group delay in the low pass filter to "time align" the drivers.
http://www.diyaudio.com/forums/mult...sover-high-efficiency-loudspeaker-system.html
http://www.diyaudio.com/forums/mult...sover-high-efficiency-loudspeaker-system.html
John: appreciate the clarification, and the link. I rushed through the thread and missed the dsp part. On a side note, in communications between us over 10 years ago, you stated that "Round tractrix horns absolutely smoke rectangulars". Based on my recent experiences, you are 100% spot on !!
Has anyone found a good source for horn design?
I have the JMLC and OSWG spreadsheet, trying to work out how best to input all the points into cad so I can CNC out a curved profile with which to turn these on my lathe.
Does Hornresp output accurate points, seems like the least intuitive software to get started with...
I have the JMLC and OSWG spreadsheet, trying to work out how best to input all the points into cad so I can CNC out a curved profile with which to turn these on my lathe.
Does Hornresp output accurate points, seems like the least intuitive software to get started with...
Hi David, thank...
Is there a database of drivers?
Or an easy definitive basic guide of how to get started?
Ive seen a few guides floating around, but unsure if there is one you would advocate.
Is there a database of drivers?
Or an easy definitive basic guide of how to get started?
Ive seen a few guides floating around, but unsure if there is one you would advocate.
Found a nice guide on Home Theatre, managed to get it to start designing the horn, however Radian pdf's contain none of the parameters I need to enter.
Can anyone help?
Can anyone help?
Horn Response is primarily a low frequency modeling program. It is too limited to accurately model the response of a compression driver. In addition, you'll have to measure and derive your own T/S parameters for the compression driver. There is not a single manufacturer that publishes the full T/S parameters for a compression driver. Akabak is a more capable program to simulate the response of a compression driver. However, it has a steep learning curve.
Thank JLH, I see by your pic you are a Horn lover too?
Did you turn those beastly tractrix's yourself? What kinda lathe are you using?
Did you turn those beastly tractrix's yourself? What kinda lathe are you using?
I took my $300 Sears lathe and built another stock head stand for it with a pulley reduction system. A couple pillow bearings, a metal face plate shaft, two pulleys and a belt is all that was needed. I can turn stuff as slow as 135 RPM. I’ve turned some big stuff on it. The largest being a 115Hz tractrix horn which had a 37” diameter mouth. I turned it in two sections, each section weighing about 95 lbs a piece.
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Clever...I might try the same, was the gearing necessary, guessing the speed at the circumference is still pretty quick?
Try to do the maths for a conical horn that will be turned to form a OSWG.
Next how to glue up a segmented JMLC profile from solid cherry...
Try to do the maths for a conical horn that will be turned to form a OSWG.
Next how to glue up a segmented JMLC profile from solid cherry...
Anytime you turn something this big and heavy it has to be very balanced or turned very slow otherwise the lathe will walk across the floor and destroy itself. I start off turning at 135 RPM until the piece becomes more balanced after some material is removed. I rarely ever reached 400 RPM even when I'm doing the finish sanding. There is a tremendous amount of energy in something this big and heavy. You have to respect it because it can literally kill you if it dismounts.
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