Yes I now this but akabak complain about the smaller part just after the throat
because this is important for the horn I need to sim it with the rest.
I go look at it if I get the picture, I need somtimes more thinking, I am 58 you now.
regards
Attachments
Okay, I will look at it, but I think I can better buy hornprogram like Jhorn, but the other way it is fun play with akabak.
thanks.
Just last question, because I think I have the hang a little with akabak.
peace of your script
| *** tractrix profile from E. Forker's Tractrix spreadsheet for 300 Hz horn ***
|S_throat(m^2), S_mouth (m^2), Length (m)
S1T=0.005041000; S1M=0.007076077; L1=0.0519;
S2T=0.007076077; S2M=0.009688764; L2=0.0479;
S3T=0.009688764; S3M=0.013530724; L3=0.0506;
S4T=0.013530724; S4M=0.01865877; L4=0.0483;
S5T=0.01865877; S5M=0.026128549; L5=0.0501;
S6T=0.026128549; S6M=0.037115109; L6=0.0514; | Bass front horn injection point at 24.88cm, node=56
the part I put here is meters, you have that also put in that way.
I have 35 steps so it is different because I have not scale it and you did and afterwards put it in akabak giving some more numbers right? it is not from sheet..
I have put in all the 35 steps, that part did work now, I see also you have reverse the distances from throat to mouth, maybe this is why it works in your sheet.
thanks in advance, i think I start to get it slowly with my gray brains.
regards
peace of your script
| *** tractrix profile from E. Forker's Tractrix spreadsheet for 300 Hz horn ***
|S_throat(m^2), S_mouth (m^2), Length (m)
S1T=0.005041000; S1M=0.007076077; L1=0.0519;
S2T=0.007076077; S2M=0.009688764; L2=0.0479;
S3T=0.009688764; S3M=0.013530724; L3=0.0506;
S4T=0.013530724; S4M=0.01865877; L4=0.0483;
S5T=0.01865877; S5M=0.026128549; L5=0.0501;
S6T=0.026128549; S6M=0.037115109; L6=0.0514; | Bass front horn injection point at 24.88cm, node=56
the part I put here is meters, you have that also put in that way.
I have 35 steps so it is different because I have not scale it and you did and afterwards put it in akabak giving some more numbers right? it is not from sheet..
I have put in all the 35 steps, that part did work now, I see also you have reverse the distances from throat to mouth, maybe this is why it works in your sheet.
thanks in advance, i think I start to get it slowly with my gray brains.
regards
Welll when playing I discover things for what i say it is confusing me.
it has to do with volvotreter sheet who use point of origine always from throat, while akabak does step by step starting with next point to next point, that is why your L1.L2.L3 has just milimeters steps and I have always from point of origine who give then faulthy input for akabak, I hope you understand me, because akabak is quite complicated so I need clearness.
Other point is your throat is very small in start, do the horn not start at throat is 7.1 cm square? I see it is just 5,41 mm like in S1T (throat?) and S1M (is mouth?).
S1T=0.005041000; S1M=0.007076077; L1=0.0147;
S2T=0.007076077; S2M=0.009688764; L2=0.0541;
S3T=0.009688764; S3M=0.013530724; L3=0.0980;
S4T=0.013530724; S4M=0.01865877; L4=0.1349;
S5T=0.01865877; S5M=0.026128549; L5=0.1666;
So this last thing has to be explaned, then I have I hope al the info for akabak who is I did see very powerfull.
regards
it has to do with volvotreter sheet who use point of origine always from throat, while akabak does step by step starting with next point to next point, that is why your L1.L2.L3 has just milimeters steps and I have always from point of origine who give then faulthy input for akabak, I hope you understand me, because akabak is quite complicated so I need clearness.
Other point is your throat is very small in start, do the horn not start at throat is 7.1 cm square? I see it is just 5,41 mm like in S1T (throat?) and S1M (is mouth?).
S1T=0.005041000; S1M=0.007076077; L1=0.0147;
S2T=0.007076077; S2M=0.009688764; L2=0.0541;
S3T=0.009688764; S3M=0.013530724; L3=0.0980;
S4T=0.013530724; S4M=0.01865877; L4=0.1349;
S5T=0.01865877; S5M=0.026128549; L5=0.1666;
So this last thing has to be explaned, then I have I hope al the info for akabak who is I did see very powerfull.
regards
Kees,
Sorry I forgot to explain to you, the values for S1T, S1M, etc are cross sectional areas of the waveguide in meters^2. Sometimes, I use plain dimensions of width here and multiply by the depth of the speaker when working with, for example a flat 2-d geometry BLH with uniform wall widths. The tractrix is a 3d object and the cross sectional areas are what is needed.
So from above:
S1T=0.005041000; S1M=0.007076077; L1=0.0147;
S1T=0.00504 meters^2, S1M=0.00707 meters^2, L1=0.0147 meters
So I took Volvotreter's spreadsheet and used the area, not the dimensions in width and height. You could use that, but then multiply width and height to get area. And the axial distance in spreadsheet is from throat and in Akabak it is segment length.l
Hope that helps.
X
Sorry I forgot to explain to you, the values for S1T, S1M, etc are cross sectional areas of the waveguide in meters^2. Sometimes, I use plain dimensions of width here and multiply by the depth of the speaker when working with, for example a flat 2-d geometry BLH with uniform wall widths. The tractrix is a 3d object and the cross sectional areas are what is needed.
So from above:
S1T=0.005041000; S1M=0.007076077; L1=0.0147;
S1T=0.00504 meters^2, S1M=0.00707 meters^2, L1=0.0147 meters
So I took Volvotreter's spreadsheet and used the area, not the dimensions in width and height. You could use that, but then multiply width and height to get area. And the axial distance in spreadsheet is from throat and in Akabak it is segment length.l
Hope that helps.
X
Thanks
yes this helps a lot, volvotreter has a area scheck who I have in it, now I can fil it all in.
thanks again.
kees
Afcourse just one man can give a look at it, I have put it in akabak, I have use the cm2 from the list from volvotreter, did not like you to calculate full with distance but just width and height of the horn like in my cas mouth is 34.8 x 52.21= 1817.1 cm2 = 0.18171 m2.
I need to do more, just play and see what happens, but where is your BR port? I do see only a big one, and also, I use two speakers of 8 inch under and above, not four, so the ports need smaller to let cover it with the speaker cone.
The high freq portion has quite high efficienty if i see right.
One picture has a dip, this was because of the crossover frequenty, I did rise it to 250 hz high pas give a better plot see pictures.
So look at it with a quick look and say if I am on the good track with akabak. and some tips, I did find the port duct and now how to use now, I can just move them easely and look at plot.
When I use 12 inch like you did this baby go loud.
The plot is not oke yet, some dips and such but it is a start. when I do put 2.83 volts in the little wideband speaker it go to 108 dB, i have to damp it 0.5 for the other two woofers coming in line with a amplification of 3 in your akabak script..
thanks
kees
I need to do more, just play and see what happens, but where is your BR port? I do see only a big one, and also, I use two speakers of 8 inch under and above, not four, so the ports need smaller to let cover it with the speaker cone.
The high freq portion has quite high efficienty if i see right.
One picture has a dip, this was because of the crossover frequenty, I did rise it to 250 hz high pas give a better plot see pictures.
So look at it with a quick look and say if I am on the good track with akabak. and some tips, I did find the port duct and now how to use now, I can just move them easely and look at plot.
When I use 12 inch like you did this baby go loud.
The plot is not oke yet, some dips and such but it is a start. when I do put 2.83 volts in the little wideband speaker it go to 108 dB, i have to damp it 0.5 for the other two woofers coming in line with a amplification of 3 in your akabak script..
thanks
kees
Attachments
Last edited:
Hi I am here again, I have now did change things in akabak like port ducs, etc,
I like to have it metric, can you help me how to change that, thanks.
here the outcome of that horn, the mid/high is very sensitive, much more then the bass unit, who needs more power, maybe it is because of the woofers, need more sensitive woofers? see script attachment. On the other hand, high need less power and can give very high details/very low distortion in the area what is most important.
I think you like the akabak sim.
regards
I like to have it metric, can you help me how to change that, thanks.
here the outcome of that horn, the mid/high is very sensitive, much more then the bass unit, who needs more power, maybe it is because of the woofers, need more sensitive woofers? see script attachment. On the other hand, high need less power and can give very high details/very low distortion in the area what is most important.
I think you like the akabak sim.
regards
Attachments
Last edited:
Kees,
I don't have my Akabak computer back yet but may be able to run on an old computer that I have to dig out. But yes, the Tractrix is super sensitive - it will blow your away with it's clean but high SPL capability. Get some earplugs for testing - even at very low drive levels, you can hurt your ears. It is tough to find a woofer with 108dB sensitivity - so maybe using four 99dB sensitivity woofers can get you 105dB.
I don't have my Akabak computer back yet but may be able to run on an old computer that I have to dig out. But yes, the Tractrix is super sensitive - it will blow your away with it's clean but high SPL capability. Get some earplugs for testing - even at very low drive levels, you can hurt your ears. It is tough to find a woofer with 108dB sensitivity - so maybe using four 99dB sensitivity woofers can get you 105dB.
Hi
It is not a problem it is not for pa or such but for home/theatre use.
and high sensitivity mean also low distortion, that is why horns when design right are so clean, however a tractrix seems to be less wide when frequenty rise to hf.
Or I make two tractrix one for bass mid and one for mid/high, then it go loud.
Yes my ears are important, she are already damaged because I have a disco in past, I have noise in sometimes and I am 58 so hearing get less good.
regards
I have some question
the dimensions of port and such where you use *0.01 like port dimension 12 * 0.01 a port of 12 cm across is a little big or not? can I easy get back to metric what make things some easyer for me.
Vol_driver_chamber=0.15*0.001; | vol between driver cone and inj port in liters
Dia_inj=12.0 * 0.01; | Inj port dia in cm
Q_ch_front=0.5; | Q of driver inj chamber (adjust with stuffin/padding between driver and port)
Q_ch_back=0.5; | Q of driver rear chamber (adjust with stuffin/padding)
regards
the dimensions of port and such where you use *0.01 like port dimension 12 * 0.01 a port of 12 cm across is a little big or not? can I easy get back to metric what make things some easyer for me.
Vol_driver_chamber=0.15*0.001; | vol between driver cone and inj port in liters
Dia_inj=12.0 * 0.01; | Inj port dia in cm
Q_ch_front=0.5; | Q of driver inj chamber (adjust with stuffin/padding between driver and port)
Q_ch_back=0.5; | Q of driver rear chamber (adjust with stuffin/padding)
regards
some you have also name inch but al imput U use meters? or cm, i thought you did recalculate it somehow, so the confusing with me.
Tomorrow I go make the wooden horn bends, glu and bend use muscles.
is 12 cm not a little big for a port? yes it is a 12 inch woofer, I can go smaller, I did test it already give less sound.
That is why you have such strange holes in the horn?.
Ahh so, little confusing, because i did saw cm in comment.
Now we have all questions done, I hope. I get much closer.
thanks.
Last edited:
12cm was just the script I was playing with at the time - actual value was much smaller closer to 5 or 6 cm.
Sorry the units are confusing but if you realize that it wants metric meters, then you will see than when I use inches I multiply by 0.0254, and when I use cm, I multiply by 0.01, etc.
In an argument in an actual element, dimensional units can be speficified for example for DUCT, I can say diameter dD=4.0in or dD=10cm, etc. It is smart enough to parse. Same with units for electrical components. Capacitance can be C=10pF or C=10uF.
It is very flexible and powerful, just takes a little getting used to. The problem is, you are jumping into Akabak with perhaps one of the most complicated examples there is - play around with Akabakf for a DCR or simple bass reflex first to get a handle on use of nodes, radiators, positioning radiators in real 3d space (6 DOF), reflections, etc. It is a lot to learn by doing a tractrix synergy as your first Akabak problem. You are doing great though.
Sorry the units are confusing but if you realize that it wants metric meters, then you will see than when I use inches I multiply by 0.0254, and when I use cm, I multiply by 0.01, etc.
In an argument in an actual element, dimensional units can be speficified for example for DUCT, I can say diameter dD=4.0in or dD=10cm, etc. It is smart enough to parse. Same with units for electrical components. Capacitance can be C=10pF or C=10uF.
It is very flexible and powerful, just takes a little getting used to. The problem is, you are jumping into Akabak with perhaps one of the most complicated examples there is - play around with Akabakf for a DCR or simple bass reflex first to get a handle on use of nodes, radiators, positioning radiators in real 3d space (6 DOF), reflections, etc. It is a lot to learn by doing a tractrix synergy as your first Akabak problem. You are doing great though.
If you have bigger 12 cm port it is quite difficult to make it smaller ;-).
Oke I have desided to make horn different then first planned, I go your way folding the
horn in the conical side panels, glu it on them, make first the horn bend of thin plywood or mdf glu on each other make it stiff and thicker..
But I have seen your drawn you use for scaling, I did see mine is more straight then yours who go a little rounding, if I am clear enough, difficult to explane in english, but I try.
picture of mine is made with table of sheet from volvotreter, I did see yours do round up to mouth this is because of the bend who is needed to form horn, I did just saw form and want glu horn in it to get form see picture three only the point of the wood are fragile, here I need a cm extra who do not give problems with sound..
regards
Oke I have desided to make horn different then first planned, I go your way folding the
horn in the conical side panels, glu it on them, make first the horn bend of thin plywood or mdf glu on each other make it stiff and thicker..
But I have seen your drawn you use for scaling, I did see mine is more straight then yours who go a little rounding, if I am clear enough, difficult to explane in english, but I try.
picture of mine is made with table of sheet from volvotreter, I did see yours do round up to mouth this is because of the bend who is needed to form horn, I did just saw form and want glu horn in it to get form see picture three only the point of the wood are fragile, here I need a cm extra who do not give problems with sound..
regards
Attachments
Last edited:
hehehe yes now I now why you advise me to use your template.
flattening the horn bend to get proper flare your way needs some cad experience, I do this with sketchup and a flattening plugin, so I go look for it, taking it from volvotreter did not work that way, except afcourse if i do use the way in post 477 mounting flare on sides of conical panels.
I am now enough educated to go on, it is just need the hang on it and then we can sawdusting.
Ohh I did find already the tool, see the movie, for others here who want to do, looks so easy, watch after 2,32 minute.
http://www.youtube.com/watch?v=xN9Q-wF8MIE
regards and thanks.
flattening the horn bend to get proper flare your way needs some cad experience, I do this with sketchup and a flattening plugin, so I go look for it, taking it from volvotreter did not work that way, except afcourse if i do use the way in post 477 mounting flare on sides of conical panels.
I am now enough educated to go on, it is just need the hang on it and then we can sawdusting.
Ohh I did find already the tool, see the movie, for others here who want to do, looks so easy, watch after 2,32 minute.
http://www.youtube.com/watch?v=xN9Q-wF8MIE
regards and thanks.
Attachments
Last edited:
Really it is not difficult with sketchup.
Only when flatten the length is 2,3 cm to short.
see pictures what I did, it works fine I go ask that people why it is shorter, I need precision. In foto two you see when flattening it get appart from each other, I can move them back to closing again but then I get to short, and if all closed to long, only width is oke on both ends.
regards and thanks for support.
kees
Attachments
Last edited: