Hi all. What do you think about this kind of speakers?
http://www3.ocn.ne.jp/~hanbei/eng-whyspiral.html
http://www3.ocn.ne.jp/~hanbei/eng-how.html
http://www3.ocn.ne.jp/~hanbei/eng-boxmodel.html
http://www3.ocn.ne.jp/~hanbei/eng-helixl100.html
I like the Helix L-103( for dimension, looks and cost but I've not experience with diy loudspeakers so I need help to evaluate it ),
in the bottom of this page:
http://www3.ocn.ne.jp/~hanbei/eng-linearmodel.html
Thankyou in advance
Mark
http://www3.ocn.ne.jp/~hanbei/eng-whyspiral.html
http://www3.ocn.ne.jp/~hanbei/eng-how.html
http://www3.ocn.ne.jp/~hanbei/eng-boxmodel.html
http://www3.ocn.ne.jp/~hanbei/eng-helixl100.html
I like the Helix L-103( for dimension, looks and cost but I've not experience with diy loudspeakers so I need help to evaluate it ),
in the bottom of this page:
http://www3.ocn.ne.jp/~hanbei/eng-linearmodel.html
Thankyou in advance
Mark
Glup - I think you are very brave attempting this complex spiral construction as your first speaker project.
I'd start off perhaps with same driver in a simple BR box and if you are happy with driver try a more complex enclosure.?
Fostex get good reviews for full range drivers. I'm going to try one for a new project in a few months but I don't think I'd have the patients to try this spiral port design
Good luck.
I'd start off perhaps with same driver in a simple BR box and if you are happy with driver try a more complex enclosure.?
Fostex get good reviews for full range drivers. I'm going to try one for a new project in a few months but I don't think I'd have the patients to try this spiral port design
Good luck.
Well...the great problem is chose the speaker ( I want something with good sensitivity for my diy tube amp) then I'll try different solution, indeed this one will be one of these...and BR too 
I've some problem with the dimension of the speakers so I'm not sure if a standard BR can have good low frequency response ... This is what I need:
1) sensibility>90 Db ( I want to use good low power amp(5/15W).
2) dimension...I have to lay the loudspeaker on a desk 76cm high. Not a good solution indeed, but this is my condition in this moment. Max dimension: 50*30*30cm
3)cost: 200€ max
Mark
I've some problem with the dimension of the speakers so I'm not sure if a standard BR can have good low frequency response ... This is what I need:1) sensibility>90 Db ( I want to use good low power amp(5/15W).
2) dimension...I have to lay the loudspeaker on a desk 76cm high. Not a good solution indeed, but this is my condition in this moment. Max dimension: 50*30*30cm
3)cost: 200€ max
Mark
I was thinking about giving these a shot for my FE206E's. Everything is straight forward construction except the spiral and you don't have to insert it until it's right. To make the spiral I was thinking of stringing a bunch of popsicle sticks on a threaded rod. Put enough pressure that they hold their position. Splay them to form the spiral and tighten it down. A couple of layer of fiberglass resin and fiberglass cloth to stregthen it. Sand the edges for a perfect fit and slide it in.
johninCR said:
Hi johninCR, I'm not sure if I've understand how you think to make the spiral. About the popsicle sticks, you mean to fix one side of them in the screw thread...right? With glue I think... Since the tread pitch isn't the same of the spiral ( that isn't constant too) you can glue the sticks each other ( they are partially laid one at top of the others). Than the fiberglass layers to stregthen the spiral pattern. Ok? I'm right?
It seems straight forward indeed, I'm only afraid by the weight of the rod, that, sooner or later, might warp the spiral or even weaken the sticking. I think we have to consider this aspect. Maybe a good solution will be to carve the way of the spiral on a wood rod and put in the posicle sticks ( you can glue them with vinyl glue). Then you'll use the fiberglass...how does it looks?
Sorry for my bad english...I hope my answer is comprehensible
Mark
The threaded rod would need to be thin unless you used tongue depressers (like doctors use). Drill a hole near one end. Put them all on the rod. Tighten with nuts and washers on both ends. Line them up uniformly and clamp with a wood clamp. Cut them slightly longer than needed. Sand the ends to the proper length and very slight arc. Maintain the correct amount of pressure with the rod and nuts to splay them into the proper spiral, probably using a little glue as you go. Then proceed. At the end, remove the rod if you want and seal the hole.
Mr. Takenaka told me he thought sealing gap between the spiral and the sidewall of the pipe may be difficult with this method. Small pieces of a thicker wood may be less problematic, but would require more filler to make the spiral very smooth.
Maybe his cable method is easier to get right than it seems. The wood cutout method he shows is far too much work unless you have access to a CNC robotic router. My idea seemed cheap and easy enough to try.
Mr. Takenaka told me he thought sealing gap between the spiral and the sidewall of the pipe may be difficult with this method. Small pieces of a thicker wood may be less problematic, but would require more filler to make the spiral very smooth.
Maybe his cable method is easier to get right than it seems. The wood cutout method he shows is far too much work unless you have access to a CNC robotic router. My idea seemed cheap and easy enough to try.
kneadle said:
True...another reason why I've posted here. None seems to be interested to critique this spiral horn ( or spiral trasmission line?
) Unbeliever or not I hope your critique open the discussion, because I think that this speakers, if they really do what the designer says, will be a good solution for a large number of people. They are small, with good looks and they seems able to reproduce a better LF than a standard bass reflex ( for a fullrange like the Fe127 obviously!). Maybe I'm wrong because I start with diy only last year and my attention since today was for tubes kneadle said:
Do you mean these?
http://www.t-linespeakers.org/projects/davidduke/index.html
Mark
Hehehe...regards for the fantasy.
I'm looking this link:
http://www.quarter-wave.com/
I'll print these articles and I'll start to study these one too...as if I've nothing to study for my amps...oh I've forgot the university hihihihi
We never stop to learn...
I'll back when I'll know somenting more.
Mark
PS...maybe it's better that I start to study english too...sometimes I ask myself how many I'm saying
I'm looking this link:
http://www.quarter-wave.com/
I'll print these articles and I'll start to study these one too...as if I've nothing to study for my amps...oh I've forgot the university hihihihi
We never stop to learn...
I'll back when I'll know somenting more.
Mark
PS...maybe it's better that I start to study english too...sometimes I ask myself how many
I'm saying I tried modeling the larger version for the FE206E using HornResp and it showed a primary response that peaks at 32hz and drops off steeply above and below. It also showed huge spikes in response starting at 170hz and higher.
What I couldn't model was the flared entrance to the throat. It goes from full pipe size to the horn throat size in the short distance of the 1st 360 turn where the throat is formed.
It seems to make sense that the spiral would filter out the HF response and eliminate those peaks. To get good results the combination of flared entrance and spiral flow of the horn would need to extend the primary response into higher frequencies. The only way to find out is to build one.
Another alternative is that it is some kind of broad band BR port whose horn shape amplifies the frequencies allowed to enter it.
What I couldn't model was the flared entrance to the throat. It goes from full pipe size to the horn throat size in the short distance of the 1st 360 turn where the throat is formed.
It seems to make sense that the spiral would filter out the HF response and eliminate those peaks. To get good results the combination of flared entrance and spiral flow of the horn would need to extend the primary response into higher frequencies. The only way to find out is to build one.
Another alternative is that it is some kind of broad band BR port whose horn shape amplifies the frequencies allowed to enter it.
it seems like nobody knows anything about this kind of design.
i also disccussed a little bit with the author of the site, who seems pretty honest.
i would build a little pair when i would have finished with the speakers i'm actually building, because i think that all we need is someone else than hanbei that could comment this design's sound
i also disccussed a little bit with the author of the site, who seems pretty honest.
i would build a little pair when i would have finished with the speakers i'm actually building, because i think that all we need is someone else than hanbei that could comment this design's sound
I believe that this particular design can be described with a method similar to what Martin King has used in his mathcad models- but the models on quarter-wave.com don't appear to have that capability. Someone please correct me if I'm wrong.
What it appears to be is a transmission line loaded bass reflex !!!
This is a bit different from the mass loaded transmission line. It has been said that the ML-TL is not a transmission line at all, since the physical length is shorter than the quarter wavelength of bass tones as low as they produce. However, I believe that it has also been shown that ML-TLs do not behave the way you would expect for a bass reflex enclosure modeled as a helmholtz resonator.
A classic helmholtz resonator is a large sphere with a small tube connected to it; the air in the sphere acts purely as a spring, and is only compressed. The air in the tube (port) acts as a mass, and only moves. As the length of the port approaches the wavelength of the tuning frequency, the equation describing the resonant frequency of the system breaks down.
I believe that in a ML-TL (this is just how I understand what Martin has done, and how these work- someone else may chose to comment)- the air in the box starts to act not only as a spring; but also as a mass. You can visualize it as a distributed string with a distributed mass. A steel spring is like this, and has its own resonant frequency- this corresponds to an unloaded transmission line. If you hang a mass from a steel spring, it will vibrate at a lower frequency.
Now imagine that you hang a heavy spring from the first spring; what happens now? That's what I say this is like. I say that the difference between a ML-TL and a TL-LBR (transmission line loaded bass reflex ) is that the ML-TL is like a large spring with a small mass attached to the end, and a TL-LBR is like a smaller spring with a large unloaded spring attached to the end.
I'm not 100% sure how to model it mathematically; but I believe that Martin's worksheets can be extended to cover this.
Any comments?
Joe
What it appears to be is a transmission line loaded bass reflex
!!!This is a bit different from the mass loaded transmission line. It has been said that the ML-TL is not a transmission line at all, since the physical length is shorter than the quarter wavelength of bass tones as low as they produce. However, I believe that it has also been shown that ML-TLs do not behave the way you would expect for a bass reflex enclosure modeled as a helmholtz resonator.
A classic helmholtz resonator is a large sphere with a small tube connected to it; the air in the sphere acts purely as a spring, and is only compressed. The air in the tube (port) acts as a mass, and only moves. As the length of the port approaches the wavelength of the tuning frequency, the equation describing the resonant frequency of the system breaks down.
I believe that in a ML-TL (this is just how I understand what Martin has done, and how these work- someone else may chose to comment)- the air in the box starts to act not only as a spring; but also as a mass. You can visualize it as a distributed string with a distributed mass. A steel spring is like this, and has its own resonant frequency- this corresponds to an unloaded transmission line. If you hang a mass from a steel spring, it will vibrate at a lower frequency.
Now imagine that you hang a heavy spring from the first spring; what happens now? That's what I say this is like. I say that the difference between a ML-TL and a TL-LBR (transmission line loaded bass reflex
) is that the ML-TL is like a large spring with a small mass attached to the end, and a TL-LBR is like a smaller spring with a large unloaded spring attached to the end.I'm not 100% sure how to model it mathematically; but I believe that Martin's worksheets can be extended to cover this.
Any comments?
Joe
Joe,
The spring analogy makes sense and using a spiral might be a good way to make a BR port short with nice flared ends using a consistent spiral. The same volume internally, same effective length, but short and fat.
I think what makes this some kind of horn though is that the cross sectional area of the air passage expands as the spiral changes. At the end the cross sectional area is the full pipe, but at the beginning it is the area of the opening formed by the first full turn between the center tube and the pipe wall.
The spring analogy makes sense and using a spiral might be a good way to make a BR port short with nice flared ends using a consistent spiral. The same volume internally, same effective length, but short and fat.
I think what makes this some kind of horn though is that the cross sectional area of the air passage expands as the spiral changes. At the end the cross sectional area is the full pipe, but at the beginning it is the area of the opening formed by the first full turn between the center tube and the pipe wall.
Dave,
If I came up with the idea and tried it with good results, I sure couldn't explain it either.
I noticed the spirals are opposite directions for a pair of speakers, I guess to easily make sure they are identical. I inquired about a sonic difference, but never got an answer. Since fluids naturally spin a certain direction, I'd think a spiral stimulating that direction of flow would function better.
If I came up with the idea and tried it with good results, I sure couldn't explain it either.
I noticed the spirals are opposite directions for a pair of speakers, I guess to easily make sure they are identical. I inquired about a sonic difference, but never got an answer. Since fluids naturally spin a certain direction, I'd think a spiral stimulating that direction of flow would function better.
I built a spiral shaped enclosure based on particle theory, that is, spirals are used to separate particles from their suspended fluids. I wonder if the phenomenon isn't observable with sound waves.
But there's the difficulty: light is only an observed phenomenon that can be described using two different and exclusive models, that of a wave and that of a particle. Is this true of the phenomenon of sound? Can it be described as a particle, exclusive of its properties as a wave?
Dave
But there's the difficulty: light is only an observed phenomenon that can be described using two different and exclusive models, that of a wave and that of a particle. Is this true of the phenomenon of sound? Can it be described as a particle, exclusive of its properties as a wave?
Dave
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