CGS-->MKS
There are 2 systems of measurement using metric units.
The MKS sustem (Meter, kilogram, Second) and the CGS (centimeter, gram, Second).
The CGS system is slowly loosing it's following as most scientists convert to the MKS system.
However, it seems that among the electrical engineering crowd the CGS system is still quite popular.
Audio Engineering is a subset of Electrical engineering and there is still quite a bit of favor for at least the use of centimeters, if not the entire CGS system.
Hornresponse uses cm units as do most other simulation programs.
Dave
Sorry for the derailing of this thread
There are 2 systems of measurement using metric units.
The MKS sustem (Meter, kilogram, Second) and the CGS (centimeter, gram, Second).
The CGS system is slowly loosing it's following as most scientists convert to the MKS system.
However, it seems that among the electrical engineering crowd the CGS system is still quite popular.
Audio Engineering is a subset of Electrical engineering and there is still quite a bit of favor for at least the use of centimeters, if not the entire CGS system.
Hornresponse uses cm units as do most other simulation programs.
Dave
Sorry for the derailing of this thread
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I have downloaded stepped-TH.xls sheet for folding a box, but I think it is not adequaat because it has not a constant tapered line, there is a straight piece of line, then again with some more cm2.
folding a box is I think best to cut it in parts and make the folding.
The xls sheet has just one kind of box? if I do fill in a slim box 3 times folded it prints just a part of the box on screen.
I use cm units here so it is easy.
thanks
folding a box is I think best to cut it in parts and make the folding.
The xls sheet has just one kind of box? if I do fill in a slim box 3 times folded it prints just a part of the box on screen.
I use cm units here so it is easy.
thanks
Ooops, my bad - posted that Q in the wrong thread, I was working on another project that had the option of 4,6 & 8ohm drive units 
*confusion with my filing system, secretary has been sacked!
*confusion with my filing system, secretary has been sacked!
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I did make some errors, so I have to drawn again, the box will not be much different of size.
I did see also just in hornresp that it can a lot better also, with smaller coil.
keep follow.
i downloaded the .zip file into sketchup and found no dimensions, that's why i asked about the dimensions.
smaller coil? do you mean an inductor in the circuit? in series with the woofer?
http://www.diyaudio.com/forums/subwoofers/127908-jbells-set-four-tapped-horns-16.html
Post #155:
"As to corner reflectors: it seems that they should be used sparingly, and mainly for structural reasons; screamerusa's experiments provide interesting food for thought, and it will take experimenting to optimize the placement and size of corner reflectors. The only thing that is certain about reflectors is that they reduce the internal volume, and that is generally not a good thing."
Post #155:
"As to corner reflectors: it seems that they should be used sparingly, and mainly for structural reasons; screamerusa's experiments provide interesting food for thought, and it will take experimenting to optimize the placement and size of corner reflectors. The only thing that is certain about reflectors is that they reduce the internal volume, and that is generally not a good thing."
I have measure the corner volume, the reflectors smallest part is some bigger then needed so it wil not reduce the volume. the same with folding i did step by step measure the height
in the foldings a la hornresp output, and so the panel has automatic correct placement. I did start with the volvotreters folding scheme and then work out the proper length.
But I was forgotten the conus correction, it has to be done, I did not now.
regards
in the foldings a la hornresp output, and so the panel has automatic correct placement. I did start with the volvotreters folding scheme and then work out the proper length.
But I was forgotten the conus correction, it has to be done, I did not now.
regards
Attachments
If you have an expansion from the 20.6 just before the corner to 21 just after the corner, then you should continue that expansion smoothly (in comparison to the wavelengths) through the corner.
We have seen from earlier experiment that a throttle has a disproportionate effect if implemented in the wave route. Similarly a short and small expansion that returns to the normal area has a lesser effect, much less it seems.
Using that evidence, then the minimum width in the route around the corner must be >=20.8, at half way around.
Smaller will appear as a throttle, whereas bigger should have a minimal effect.
But at the wavelengths we are handling, does the addition of the corner corrector give a measurable, or audible improvement? Or does it just look "right"?
I recall one of our experts stating that a bass horn could have parallel sections (no expansion) that "stepped" up the area, in discrete stages from throat to mouth and it would perform just the same as a smoothly expanded horn shape. Can someone remember who and exactly what was stated?
We have seen from earlier experiment that a throttle has a disproportionate effect if implemented in the wave route. Similarly a short and small expansion that returns to the normal area has a lesser effect, much less it seems.
Using that evidence, then the minimum width in the route around the corner must be >=20.8, at half way around.
Smaller will appear as a throttle, whereas bigger should have a minimal effect.
But at the wavelengths we are handling, does the addition of the corner corrector give a measurable, or audible improvement? Or does it just look "right"?
I recall one of our experts stating that a bass horn could have parallel sections (no expansion) that "stepped" up the area, in discrete stages from throat to mouth and it would perform just the same as a smoothly expanded horn shape. Can someone remember who and exactly what was stated?
it looks really nice. are the box dimensions the same as for the original on page 1? so are sides a, b, c, d, e, f the same length and width?
Hi
The dimensions are not the same, I did need to do different for better respons, in picture is
the dimensions given, or download the sketchup zip file.
I need to correct the tapped horn because I have not correct the conus volume, Now I don,t now
exactly how to do this, some make a panel, others do shifting S2 to the edge of the woofer making
S1 bigger etc, but if someone can explane how to do this best i like it to hear, the conus volume of
the woofer is 2.3712 liter 23712 cc.
regards
kees
The dimensions are not the same, I did need to do different for better respons, in picture is
the dimensions given, or download the sketchup zip file.
I need to correct the tapped horn because I have not correct the conus volume, Now I don,t now
exactly how to do this, some make a panel, others do shifting S2 to the edge of the woofer making
S1 bigger etc, but if someone can explane how to do this best i like it to hear, the conus volume of
the woofer is 2.3712 liter 23712 cc.
regards
kees
Attachments
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Lab 12 single fold
Does any one have a different fold on this TH. I already built one like on the first page of the thread, and would like another. I need it to be taller and not as wide. I want to stand it in the corner. Maybe a single fold. How would you join the plywood in such a long box?
I just searched this thread again and found what I am looking for on post #181. I want to know if one on page 1 and this one, on post #181 would work in the same room or would there be any issues? Thanks, Bill
Does any one have a different fold on this TH. I already built one like on the first page of the thread, and would like another. I need it to be taller and not as wide. I want to stand it in the corner. Maybe a single fold. How would you join the plywood in such a long box?
I just searched this thread again and found what I am looking for on post #181. I want to know if one on page 1 and this one, on post #181 would work in the same room or would there be any issues? Thanks, Bill
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Bill,
Path length is longer on the page one version, it goes lower and would require the top cabinets to be delayed longer than the shorter path length version on page 181.
That said, if they are not next to the tops, they are not aligned anyway.
The 181 post is only 96", requiring no joining.
I have simply done lap joints with a backing piece of wood screwed on when I needed to join plywood. The little space the added lap reduces is generally of no consequence in a large cabinet.
Art
