jbell: I have the feeling you started with a much bigger version, and pared it down until you got the the point of no return. You certainly kept us busy. Nice work.
Regards,
tb46; I mainly put them in to brace the box, knowing thay would not cause any restricshoins.
Thanks for looking into this for me. I had a sinking feeling when you said yours did not come out as good as my simulashoin.
I was thinking of putting reflectors on the sides of the S1,S2 area in a "v" and making the width of the area 3.5" all the way. That would make the speaker mounting board stiffer, and you think it would help with the dips on the high end? thats a ++ if it will not effect the low end output.
Can you get it to bend at S3?
I will be building next week, and pass along any changes for the record.
Thanks again for all you time. Andy
Hi 4pyros,
"...Can you get it to bend at S3?..."
It can be done, but it's a bit of work. Here is just a quick look at it. After you make any modifications to the indicated panels you also have to work your way through the bends again, and transfer the result to Hornresp, and make modifications to the drawing, and so on.....
As to the S1/S2 area: screamerusa found it to be important to reduce S1, maybe take another look at the furybox. I think it can only help.
Regards,
"...Can you get it to bend at S3?..."
It can be done, but it's a bit of work. Here is just a quick look at it. After you make any modifications to the indicated panels you also have to work your way through the bends again, and transfer the result to Hornresp, and make modifications to the drawing, and so on.....
As to the S1/S2 area: screamerusa found it to be important to reduce S1, maybe take another look at the furybox. I think it can only help.
Regards,
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Hi Oliver,
I made a small correction on your drawing to get the outlines of the SS15 inclusive the corner volumes (just a rough estimation actually). Is there any way you can calculate the exact volume differences between prediction and real cab in the area between reference points 9 to S4?
https://lh3.googleusercontent.com/_nSWmrMRpHJI/TXlQMEHl1dI/AAAAAAAAAMA/elFJd7yFk3o/TB_03.jpg
I made a small correction on your drawing to get the outlines of the SS15 inclusive the corner volumes (just a rough estimation actually). Is there any way you can calculate the exact volume differences between prediction and real cab in the area between reference points 9 to S4?
https://lh3.googleusercontent.com/_nSWmrMRpHJI/TXlQMEHl1dI/AAAAAAAAAMA/elFJd7yFk3o/TB_03.jpg
Hi Djim,
It's not as straight forward as it looks to get the respective volumes, e.g.: You may have noticed, that I like looking at the S4 dimension at right-angle to the centerline of the respective horn section in reference to the position of the cone, not necessarily the mounting position of the basket. Also, jbells explanation of his target flare makes a lot of sense. The purple line is just to check that I'm not too far off. Anyway, see the attachment.
Regards,
It's not as straight forward as it looks to get the respective volumes, e.g.: You may have noticed, that I like looking at the S4 dimension at right-angle to the centerline of the respective horn section in reference to the position of the cone, not necessarily the mounting position of the basket. Also, jbells explanation of his target flare makes a lot of sense. The purple line is just to check that I'm not too far off. Anyway, see the attachment.
Regards,
Thanks Oliver,
I think you forget something with your method. As long you don't introduce another reference point this goes straight into the corner you never get an accurate volume calculation (see purple line). That is my problem with this method. It also cuts of the path length a little (see blue line) although this is to small to be significant. So you wont see that back in your horizontal representation. If someone is going to use corner bracing from just above point 9 to a little after point 10 it will cut within the path. I hope my words make sense...
I think you forget something with your method. As long you don't introduce another reference point this goes straight into the corner you never get an accurate volume calculation (see purple line). That is my problem with this method. It also cuts of the path length a little (see blue line) although this is to small to be significant. So you wont see that back in your horizontal representation. If someone is going to use corner bracing from just above point 9 to a little after point 10 it will cut within the path. I hope my words make sense...
Attachments
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The other two important reference points I show you in green (90 degrees straight on the outline of the cab). If you integrate these 3 new reference points you will see in your horizontal representation why this is important. Maybe not in volume difference but sure when it comes to air resistance, I think.
In my opinion this is exactly the reason why corner correctors (deflectors whatever...) are so 'sensitive' to the real output plot. I think JBell 'discovered' that the hard way with his big cab and his cube.
In my opinion this is exactly the reason why corner correctors (deflectors whatever...) are so 'sensitive' to the real output plot. I think JBell 'discovered' that the hard way with his big cab and his cube.
Attachments
Now I will show the difference what it makes for corner bracings.
On the left the method how it is done by the 4 reference points method.
On the right how it is done by the 7 reference points method by 2 pieces instead of one.
In 'huge' corners (like in the big cab) I suggest 3 pieces...
The importance of those 'new' 3 reference points is this: The all point the the max (corner) and minimum path width that are not 'visible' with the method that is used around here...
On the left the method how it is done by the 4 reference points method.
On the right how it is done by the 7 reference points method by 2 pieces instead of one.
In 'huge' corners (like in the big cab) I suggest 3 pieces...
The importance of those 'new' 3 reference points is this: The all point the the max (corner) and minimum path width that are not 'visible' with the method that is used around here...
Attachments
Not at all JBell... and thanks for my broken lips after the cold carnaval event over here
"stupid" flutes...(Oh and another more important thing I still on that challenge, improving that 'silly' concept of yours!)
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And my second suggestion (before I fall in sleep). If you worry about point A, it almost follows the outline of the driver's cone. You can see it as a driver volume correction (in both ways). Tell me what you think...
Btw it was my intention to lift the driver panel parallel from its original position... sorry for my skills
The extra volume around corner one is now partly 'used' by the driver panel.
Btw it was my intention to lift the driver panel parallel from its original position... sorry for my skills
The extra volume around corner one is now partly 'used' by the driver panel.
Attachments
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I am lost in the need for this "area" accuracy around the bends.
Previously I have seen the experts and good amateurs telling us that for low freqency reproduction that step changes in area make no difference to the sound that comes out.
I remember one designer saying that an LF horn would work just as well with cascaded parallel sections of increasing area.
They further went on to say that filling in the corners with rounded profile was a waste of effort and material.
DJM in his graphical method of minimising the "area" change is slowly approaching a curved "bend".
Is this really going to affect a speaker that has a maximum upper passband frequency of 60 to 120Hz?
Previously I have seen the experts and good amateurs telling us that for low freqency reproduction that step changes in area make no difference to the sound that comes out.
I remember one designer saying that an LF horn would work just as well with cascaded parallel sections of increasing area.
They further went on to say that filling in the corners with rounded profile was a waste of effort and material.
DJM in his graphical method of minimising the "area" change is slowly approaching a curved "bend".
Is this really going to affect a speaker that has a maximum upper passband frequency of 60 to 120Hz?
Hi AndrewT,
Post #598: "Is this really going to affect a speaker that has a maximum upper passband frequency of 60 to 120Hz."
I doubt it, but both screamerusa and jbell have seen measurable differences in their respective tapped horns by using reflectors. So far nobody has reported controlled and repeatable measurements of the effects of reflectors in a tapped horn. So beyond screamerusa's and jbell's reports, we are just guessing.
I think they are most useful for freeing up space for wheels, handholds, and spots to the protect the input connectors. They can also be great to strengthen the box. Reflectors right around the throat area do make a difference in Hornresp, particularly when they affect the S1/S2 region.
One more note to the centerline discussion, soho54 has suggested that his corner method (which is what I'm using now) arrives at dimensions that produce Hornresp outputs that correspond to his measured results. I've tried a number of different ways, and there is just not enough difference to matter much. I do think it is worthwhile to enter a design into AkAbak prior to building, as most of the tapped horns that have multiple bends also end up having multiple tapers (flare rates), here AkAbak can give you a more correct simulation.
Regards,
Post #598: "Is this really going to affect a speaker that has a maximum upper passband frequency of 60 to 120Hz."
I doubt it, but both screamerusa and jbell have seen measurable differences in their respective tapped horns by using reflectors. So far nobody has reported controlled and repeatable measurements of the effects of reflectors in a tapped horn. So beyond screamerusa's and jbell's reports, we are just guessing.
I think they are most useful for freeing up space for wheels, handholds, and spots to the protect the input connectors. They can also be great to strengthen the box. Reflectors right around the throat area do make a difference in Hornresp, particularly when they affect the S1/S2 region.
One more note to the centerline discussion, soho54 has suggested that his corner method (which is what I'm using now) arrives at dimensions that produce Hornresp outputs that correspond to his measured results. I've tried a number of different ways, and there is just not enough difference to matter much. I do think it is worthwhile to enter a design into AkAbak prior to building, as most of the tapped horns that have multiple bends also end up having multiple tapers (flare rates), here AkAbak can give you a more correct simulation.
Regards,