I have been scheming a replacement for my edgar 75 hz horns.
As I have gone back and forth on whether to make another horn or make it simple with a closed box (which, of course, I would obsess over to the point it is almost as complicated as a horn) there is much talk about the stiffness of the baffle with the closed box but I have read nothing concerning whether this is as important with a horn loaded enclosure.
Another question is: If one encloses the horn within a box would it be "bad" to use some of this area as the rear chamber of the horn? I know ALTEC used the inside of the flares of the 825 as some kind of filter but these areas are much smaller than the horn I am considering. Of course, additional space would be required behind the driver but this way it could be made much smaller than it would be with a separate box.
Of course I would use braces along each horn side to the outer cabinet.
You read about using three inches thick baffles with closed boxes but nothing is mentioned how important this rigidity is with a horn. Would the forces acting upon both sides of the driver in a horn make this less important?
Any counsel will be appreciated.
As I have gone back and forth on whether to make another horn or make it simple with a closed box (which, of course, I would obsess over to the point it is almost as complicated as a horn) there is much talk about the stiffness of the baffle with the closed box but I have read nothing concerning whether this is as important with a horn loaded enclosure.
Another question is: If one encloses the horn within a box would it be "bad" to use some of this area as the rear chamber of the horn? I know ALTEC used the inside of the flares of the 825 as some kind of filter but these areas are much smaller than the horn I am considering. Of course, additional space would be required behind the driver but this way it could be made much smaller than it would be with a separate box.
Of course I would use braces along each horn side to the outer cabinet.
You read about using three inches thick baffles with closed boxes but nothing is mentioned how important this rigidity is with a horn. Would the forces acting upon both sides of the driver in a horn make this less important?
Any counsel will be appreciated.
When I built my 80Hz horns I chose to brace them quite heavily. The gaps between bracing were filled with fibreglass wadding before closing up.
If you are using electrovoice evm15 drivers the rear chamber will probably be tiny due to reactance annulling, meaning the cabinet space question is moot if you want a sealed rear enclosure.
Rob
If you are using electrovoice evm15 drivers the rear chamber will probably be tiny due to reactance annulling, meaning the cabinet space question is moot if you want a sealed rear enclosure.
Rob
Attachments
I am using a Great Plains 515ghp instead of the EV.
The rear chamber supplied by Dr. Edgar was quite large since he was trying to trick more bass extension from the thing. I had made the box smaller. I use it between 125 and 500 hz. It requires some boost around 500 hz.
Since posting I do realize there is no need for more volume in the rear chamber. I am figuring on 25 liters.
I am changing them out since the current horn, though far from awful, has some audible flaws I hope I can remove. When I listen to them by themselves there is an obvious ringing that I have determined is not the room.
They go lower than I need them to and not as high as I would like. I will use a smaller throat to attempt a bit higher cutoff.
RobWells your horn construction looks similar to what I did with Edgar's pieces sent to assemble. I did not enclose this horn in a box as he would have. Instead i kept the horn shape for the sides and used pieces of 2 x 4 to strengthen the sides.
Did you subsequently enclose the horn in a box or did you leave it as shown? I certianly like the way they look unboxed but wonder if there could be some advantage of islating the horn walls?
Did you go to any extra trouble with the baffle?
Thanks for your help,
The rear chamber supplied by Dr. Edgar was quite large since he was trying to trick more bass extension from the thing. I had made the box smaller. I use it between 125 and 500 hz. It requires some boost around 500 hz.
Since posting I do realize there is no need for more volume in the rear chamber. I am figuring on 25 liters.
I am changing them out since the current horn, though far from awful, has some audible flaws I hope I can remove. When I listen to them by themselves there is an obvious ringing that I have determined is not the room.
They go lower than I need them to and not as high as I would like. I will use a smaller throat to attempt a bit higher cutoff.
RobWells your horn construction looks similar to what I did with Edgar's pieces sent to assemble. I did not enclose this horn in a box as he would have. Instead i kept the horn shape for the sides and used pieces of 2 x 4 to strengthen the sides.
Did you subsequently enclose the horn in a box or did you leave it as shown? I certianly like the way they look unboxed but wonder if there could be some advantage of islating the horn walls?
Did you go to any extra trouble with the baffle?
Thanks for your help,
Last edited:
Hi Rick,
I added braces to the other 2 sides after the pic was taken and added 18mm plywood all round. I also added external braces to the driver enclosure as there was no room inside to add any.
They ended up very heavy but very solid. The baffle is braced to the horn walls on all 4 sides.
I was very happy with them, have only stopped using them as I'm working on MEH style horns now.
Pictures a bit dark sorry..
Cheers,
Rob.
I added braces to the other 2 sides after the pic was taken and added 18mm plywood all round. I also added external braces to the driver enclosure as there was no room inside to add any.
They ended up very heavy but very solid. The baffle is braced to the horn walls on all 4 sides.
I was very happy with them, have only stopped using them as I'm working on MEH style horns now.
Pictures a bit dark sorry..
Cheers,
Rob.
Attachments
I have been interested in trying the MEH idea but worry - as complicated as they are,. is it easy to end up with something useless after all of that work? Coming up with a conventional horn has enough potential pitfalls as it is!
There is a fellow who posts here on occasion and more often at one of the KLIPSCH sites who has used the JUBILEE horn as a basis and using two KLIPSCH 15 inches woofers. He is using a 4 inches diaphragm CD to get low enough for this to work.
I love the idea of the MEH but I am chicken and I worry my woodworking skills are not up to the task.
I look forward to reading more about your project.
Just now see the speakers in your moniker. Are these based on Mr. Waslo's work?
Were these a revelation in comparison to your conventional setup?
There is a fellow who posts here on occasion and more often at one of the KLIPSCH sites who has used the JUBILEE horn as a basis and using two KLIPSCH 15 inches woofers. He is using a 4 inches diaphragm CD to get low enough for this to work.
I love the idea of the MEH but I am chicken and I worry my woodworking skills are not up to the task.
I look forward to reading more about your project.
Just now see the speakers in your moniker. Are these based on Mr. Waslo's work?
Were these a revelation in comparison to your conventional setup?
I'm only just getting my test box finished so early days yet 
The one thing I had trouble with the 80Hz midbass horn was getting a mid horn that goes low enough to meet it (500Hz) When the Synergy horns arrived on the scene I realised they could get down to ~250Hz just with mids so I became really interested in them. Then I realised that maybe bolting another pair of 12's into them would get the 'point source' thing going all the way down and lose a pair of big midbass boxes at the same time (win win situation)
Yes Bwaslo is the key to me getting them built. If you cut the panels accurately enough and make some sort of sled as outlined in his help file / pdf then you should get close enough. I took the easy route by using the BMS 4550 CD and the Celestion 4" sealed back midrange drivers. (They are known to work well.)
I think the work with them is more in the crossover / setup than the physical build. I know that the 1st time I heard pink noise coming from just the mids that I could tell they were really smooth and clean.
Cheers,
Rob.
The one thing I had trouble with the 80Hz midbass horn was getting a mid horn that goes low enough to meet it (500Hz) When the Synergy horns arrived on the scene I realised they could get down to ~250Hz just with mids so I became really interested in them. Then I realised that maybe bolting another pair of 12's into them would get the 'point source' thing going all the way down and lose a pair of big midbass boxes at the same time (win win situation)
Yes Bwaslo is the key to me getting them built. If you cut the panels accurately enough and make some sort of sled as outlined in his help file / pdf then you should get close enough. I took the easy route by using the BMS 4550 CD and the Celestion 4" sealed back midrange drivers. (They are known to work well.)
I think the work with them is more in the crossover / setup than the physical build. I know that the 1st time I heard pink noise coming from just the mids that I could tell they were really smooth and clean.
Cheers,
Rob.
Thanks for your encouragement and advice.
When I considered them I had planned on using the 4 inches CELESTIONS - though I would prefer to stick with my existing CDs - JNL 2441 w. TRUEXTENT diaphragms instead of buying another CD.
Would like it to work as a two way - because of the crossover considerations - but I can see the advantage of using the 4 inchers as filler between the two like the old B&O concept of a decades ago. That always made great sense to me even though the version of the speaker I heard did not impress me at all.
My desire was to use four ten inches woofers with the CD - but then where do you find the woofers that will work AND are two woofers really necessary?
So many questions, so much unknown ...
Audio is an art - if only science ALWAYS prevailed!
Not to mention lots of hard work putting complicated cabinets together.
I do not know Mr. Waslo but I do know that I have great appreciation for what he has given us. I need to look over his article again.
Thanks, Rob
When I considered them I had planned on using the 4 inches CELESTIONS - though I would prefer to stick with my existing CDs - JNL 2441 w. TRUEXTENT diaphragms instead of buying another CD.
Would like it to work as a two way - because of the crossover considerations - but I can see the advantage of using the 4 inchers as filler between the two like the old B&O concept of a decades ago. That always made great sense to me even though the version of the speaker I heard did not impress me at all.
My desire was to use four ten inches woofers with the CD - but then where do you find the woofers that will work AND are two woofers really necessary?
So many questions, so much unknown ...
Audio is an art - if only science ALWAYS prevailed!
Not to mention lots of hard work putting complicated cabinets together.
I do not know Mr. Waslo but I do know that I have great appreciation for what he has given us. I need to look over his article again.
Thanks, Rob
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.