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Gjallarhorn version 2


Ricci

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Here is the fold of the improved second version of the GH. The goals or main areas of improvement to be addressed with the new version are...

A cleaner fold pattern with less bends overall, less short 180 degree folds and use more 90 degree bends where possible.(The original Gjallarhorn fold had 9 bends and 5 180 degree bends. The 2nd generation has 7 bends and 4 of them are 180 degree)

Reduce the air friction and "drag" in the enclosure by reducing the amount and sharpness of bends. This should aid in reducing compression and air turbulence at higher output levels.

Increase the throat volume slightly in order to also reduce throat compression and add excursion clearance.

Match closely the response shape and corner of the original.

Reduce mechanical/motor noise and the outer panel vibration especially at the mouth by moving the driver deeper into the enclosure and allow for more bracing around the driver baffle and mounting area. Less cabinet vibration at heavy output.

Switch the driver to a mounting position that places it in a horizontal position in all typical cabinet orientations both lying flat and standing. The old GH places the driver in a vertical position when operating in the standing position which could lead to cone sag over time.

Performance should be virtually identical but if there is any performance difference it would be a slight nod to the new version simply due to a better braced cab around the driver and less bends so a little better air flow through the horn. If anything it would show up at war volume with compression sweeps but I'm just guessing here.The cabinet now has a pair of side hatches for driver access.

Attached is screen capture of the first generation fold and the second generation fold...

 

Below is the Akabak script for simulating the GH 2 which includes the cone volume and the driver frame and motor in the horn path.

 

|========================================================================================================

 

|REQUIRED AKABAK SETTINGS:

 

|File > Preferences > Physical system constants:

 

|Sound velocity c = 344m/s

|Medium density rho = 1.205kg/m3

 

|Sum > Acoustic power:

 

|Frequency range = 10Hz to 20kHz

|Points = 533

|Input voltage = 1.0V rms

|Integration = 2Pi-sr

|Integration steps = 1 degree ... 1 degree

|Integration method = Cross

 

|========================================================================================================

 

Def_Const |

{

|Length, area and volume values converted to metres, square metres and cubic metres:

 

S1  =   115.353e-4;  |Horn segment 1 throat area (sq cm)
S2  =   633.5e-4;  |Horn segment 1 mouth area and horn segment 2 throat area (sq cm)+278cm driver (cm)355.51728
S3  =   387.92568e-4;  |Horn segment 2 mouth area and horn segment 3 throat area (sq cm)end cone
S4  =   416.03208e-4;  |Horn segment 3 mouth area and horn segment 4 throat area (sq cm)
S5  =   589.77552e-4;  |Horn segment 4 mouth area and horn segment 5 throat area (sq cm)
S6  =   418.1544e-4;  |Horn segment 5 mouth area and horn segment 6 throat area (sq cm)
S7  =   420.162e-4;  |Horn segment 6 mouth area and horn segment 7 throat area (sq cm)
S8  =   597.86328e-4;  |Horn segment 7 mouth area and horn segment 8 throat area (sq cm)
S9  =   425.43912e-4;  |Horn segment 8 mouth area and horn segment 9 throat area (sq cm)
S10  =   528.5724e-4;  |Horn segment 9 mouth area and horn segment 10 throat area (sq cm)
S11  =   750.72768e-4;  |Horn segment 10 mouth area and horn segment 11 throat area (sq cm)
S12  =   533.21856e-4;  |Horn segment 11 mouth area and horn segment 12 throat area (sq cm)
S13  =   659.52528e-4;  |Horn segment 12 mouth area and horn segment 13 throat area (sq cm)
S14  =   727.95576e-4;  |Horn segment 13 mouth area and horn segment 14 throat area (sq cm)
S15  =   684.36216e-4;  |Horn segment 14 mouth area and horn segment 15 throat area (sq cm)
S16  =   730.36488e-4;  |Horn segment 15 mouth area and horn segment 16 throat area (sq cm)
S17  =   664.34352e-4;  |Horn segment 16 mouth area and horn segment 17 throat area (sq cm)
S18  =   666.40848e-4;  |Horn segment 17 mouth area and horn segment 18 throat area (sq cm)
S19  =   947.07096e-4;  |Horn segment 18 mouth area and horn segment 19 throat area (sq cm)
S20  =   673.1196e-4;  |Horn segment 19 mouth area and horn segment 20 throat area (sq cm)
S21  =   817.32264e-4;  |Horn segment 20 mouth area and horn segment 21 throat area (sq cm)
S22  =   1160.90904e-4;  |Horn segment 21 mouth area and horn segment 22 throat area (sq cm)
S23  =   824.60736e-4;  |Horn segment 22 mouth area and horn segment 23 throat area (sq cm)
S24  =   960.09168e-4;  |Horn segment 23 mouth area and horn segment 24 throat area (sq cm)
S25  =   1363.84872e-4;  |Horn segment 24 mouth area and horn segment 25 throat area (sq cm)
S26  =   968.86776e-4;  |Horn segment 25 mouth area and horn segment 26 throat area (sq cm)
S27  =   1092.93744e-4;  |Horn segment 26 mouth area and horn segment 27 throat area (sq cm)
S28  =  1629.82704e-4;  |Horn segment 27 mouth area and horn segment 28 throat area (sq cm)
S29  =   1209.26352e-4;  |Horn segment 28 mouth area and horn segment 29 throat area (sq cm)
S30  =   1211.32848e-4;  |Horn segment 29 mouth area and horn segment 30 throat area (sq cm)
S31  =   1347.90264e-4;  |Horn segment 30 mouth area and horn segment 31 throat area (sq cm)
S32  =   1274.76864e-4;  |Horn segment 31 mouth area and horn segment 32 throat area (sq cm)
S33  =   1365.79896e-4;  |Horn segment 32 mouth area and horn segment 33 throat area (sq cm)
S34  =   1334.42304e-4;  |Horn segment 33 mouth area and horn segment 34 throat area (sq cm)
S35  =   1629.82704e-4;  |Horn segment 34 mouth area and horn segment 35 throat area (sq cm)
S36  =   2465.39016e-4;  |Horn segment 35 mouth area and horn segment 36 throat area (sq cm)
S37  =   1867.81368e-4;  |Horn segment 36 mouth area and horn segment 37 throat area (sq cm)
S38  =   1882.21104e-4;  |Horn segment 37 mouth area and horn segment 38 throat area (sq cm)
S39  =   1457e-4;  |Horn segment 38 mouth area and horn segment 39 throat area (sq cm)-716cm driver 2172.56736
S40  =   2115e-4;  |Horn segment 39 mouth area and horn segment 40 throat area (sq cm)-716cm driver 2830.716
S41  =   2088.1908e-4;  |Horn segment 40 mouth area and horn segment 41 throat area (sq cm)end motor
S42  =   2076.1452e-4;  |Horn segment 41 mouth area and horn segment 42 throat area (sq cm)
S43  =   2416.74888e-4;  |Horn segment 42 mouth area and horn segment 43 throat area (sq cm)
S44  =   2432.17872e-4;  |Horn segment 43 mouth area and horn segment 44 throat area (sq cm)
S45  =   3562.97376e-4;  |Horn segment 44 mouth area (sq cm)

 

 

L12 =     23.777e-2;  |Horn segment 1 axial length (cm)
L23 =     19.048e-2;  |Horn segment 2 axial length (cm)
L34 =     16.533e-2;  |Horn segment 3 axial length (cm)
L45 =    2.8535e-2;  |Horn segment 4 axial length (cm)
L56 =    2.8535e-2;  |Horn segment 5 axial length (cm)
L67 =     1.2e-2;  |Horn segment 6 axial length (cm)
L78 =     2.89e-2;  |Horn segment 7 axial length (cm)
L89 =    2.89e-2;  |Horn segment 8 axial length (cm)
L910 =   60.598e-2;  |Horn segment 9 axial length (cm)
L1011 =   3.6305e-2;  |Horn segment 10 axial length (cm)
L1112 =  3.6305e-2;  |Horn segment 11 axial length (cm)
L1213 =    74.186e-2;  |Horn segment 12 axial length (cm)
L1314 =   2.43e-2;  |Horn segment 13 axial length (cm)
L1415 =   2.003e-2;  |Horn segment 14 axial length (cm)
L1516 =   2.058e-2;  |Horn segment 15 axial length (cm)
L1617 =  2.564e-2;  |Horn segment 16 axial length (cm)
L1718 =  1.2e-2;  |Horn segment 17 axial length (cm)
L1819 =   4.579e-2;  |Horn segment 18 axial length (cm)
L1920 =  4.579e-2;  |Horn segment 19 axial length (cm)
L2021 =  84.736e-2;  |Horn segment 20 axial length (cm)
L2122 =  5.614e-2;  |Horn segment 21 axial length (cm)
L2223 =  5.614e-2;  |Horn segment 22 axial length (cm)
L2324 =  79.590e-2;  |Horn segment 23 axial length (cm)
L2425 =  6.595e-2;  |Horn segment 24 axial length (cm)
L2526 =  6.595e-2;  |Horn segment 25 axial length (cm)
L2627 =  72.908e-2;  |Horn segment 26 axial length (cm)
L2728 = 7.7865e-2;  |Horn segment 27 axial length (cm)
L2829 =  7.7865e-2;  |Horn segment 28 axial length (cm)
L2930 = 1.2e-2;  |Horn segment 29 axial length (cm)
L3031 = 4.658e-2;  |Horn segment 30 axial length (cm)
L3132 = 3.570e-2;  |Horn segment 31 axial length (cm)
L3233 = 4.071e-2;  |Horn segment 32 axial length (cm)
L3334 = 3.942e-2;  |Horn segment 33 axial length (cm)
L3435 = 24.498e-2;  |Horn segment 34 axial length (cm)
L3536 = 11.79e-2;  |Horn segment 35 axial length (cm)
L3637 = 11.79e-2;  |Horn segment 36 axial length (cm)
L3738 = 1.2e-2;  |Horn segment 37 axial length (cm)
L3839 = 7.039e-2;  |Horn segment 38 axial length (cm)
L3940 = 5.276e-2;  |Horn segment 39 axial length (cm)
L4041 = 10.539e-2;  |Horn segment 40 axial length (cm)
L4142 = 4.256e-2;  |Horn segment 41 axial length (cm)
L4243 = 32.943e-2;  |Horn segment 42 axial length (cm)
L4344 =  0.678e-2;  |Horn segment 43 axial length (cm)
L4445 =  10.311e-2;  |Horn segment 44 axial length (cm)

 

 

|Parameter Conversions:

Sd  = 1194.6e-4;  |Diaphragm area (sq cm)

}

|========================================================================================================

 

|Network node numbers for this tapped horn system:

 

|               0-Voltage-1

|                         |

|           -Chamber-5-Driver---

|          |                    |

|8-Segment-9-Segment-10-Segment-11-Segment-12-Segment-13-Segment-14-Segment-15-Segment-16-Segment-17-Segment-18-Segment-19-Segment-20-Segment-21-Segment-22-Segment-23-Segment-24-Segment-25-Segment-26-Segment-27-Segment-28-Segment-29-Segment-30-Segment-31-Segment-32-Segment-33-Segment-34-Segment-35-Segment-36-Segment-37-Segment-38-Segment-39-Segment-40-Segment-41-Segment-42-Segment-43-Segment-44-Segment-45-Segment-46-Segment-47-Segment-48-Segment-49-Segment-50-Segment-51-Segment-52-Radiator

 

|========================================================================================================

 

Def_Driver 'Driver'

 

  Sd=1194.6cm2

  Bl=26.93Tm

  Cms=1.19E-04m/N

  Rms=8.58Ns/m

  fs=20.50Hz  |Mmd = 482.71g not recognised by AkAbak, fs calculated and used instead

  Le=2.80mH

  Re=3.78ohm

 

  ExpoLe=1

 

System 'System'

 

  Driver Def='Driver''Driver'

    Node=1=0=9=46

 

  Waveguide 'Segment 1'

    Node=8=9

    STh={S1}

    SMo={S2}

    Len={L12}

 

  Waveguide 'Segment 2'

    Node=10=9

    STh={S3}

    SMo={S2}

    Len={L23}

 

  Waveguide 'Segment 3'

    Node=10=11

    STh={S3}

    SMo={S4}

    Len={L34}

 

Waveguide 'Segment 4'

    Node=11=12

    STh={S4}

    SMo={S5}

    Len={L45}

  

  Waveguide 'Segment 5'

    Node=13=12

    STh={S6}

    SMo={S5}

    Len={L56}

 

  Waveguide 'Segment 6'

    Node=13=14

    STh={S6}

    SMo={S7}

    Len={L67}

  

  Waveguide 'Segment 7'

    Node=14=15

    STh={S7}

    SMo={S8}

    Len={L78}

  

  Waveguide 'Segment 8'

    Node=16=15

    STh={S9}

    SMo={S8}

    Len={L89}

  

  Waveguide 'Segment 9'

    Node=16=17

    STh={S9}

    SMo={S10}

    Len={L910}

  

  Waveguide 'Segment 10'

    Node=17=18

    STh={S10}

    SMo={S11}

    Len={L1011}

  

  Waveguide 'Segment 11'

    Node=19=18

    STh={S12}

    SMo={S11}

    Len={L1112}

  

  Waveguide 'Segment 12'

    Node=19=20

    STh={S12}

    SMo={S13}

    Len={L1213}

  

  Waveguide 'Segment 13'

    Node=20=21

    STh={S13}

    SMo={S14}

    Len={L1314}

  

  Waveguide 'Segment 14'

    Node=22=21

    STh={S15}

    SMo={S14}

    Len={L1415}

  

  Waveguide 'Segment 15'

    Node=22=23

    STh={S15}

    SMo={S16}

    Len={L1516}

  

  Waveguide 'Segment 16'

    Node=24=23

    STh={S17}

    SMo={S16}

    Len={L1617}

  

  Waveguide 'Segment 17'

    Node=24=25

    STh={S17}

    SMo={S18}

    Len={L1718}

  

  Waveguide 'Segment 18'

    Node=25=26

    STh={S18}

    SMo={S19}

    Len={L1819}

  

  Waveguide 'Segment 19'

    Node=27=26

    STh={S20}

    SMo={S19}

    Len={L1920}

  

  Waveguide 'Segment 20'

    Node=27=28

    STh={S20}

    SMo={S21}

    Len={L2021}

  

  Waveguide 'Segment 21'

    Node=28=29

    STh={S21}

    SMo={S22}

    Len={L2122}
    

  Waveguide 'Segment 22'

    Node=30=29

    STh={S23}

    SMo={S22}

    Len={L2223}

  

  Waveguide 'Segment 23'

    Node=30=31

    STh={S23}

    SMo={S24}

    Len={L2324}

  

  Waveguide 'Segment 24'

    Node=31=32

    STh={S24}

    SMo={S25}

    Len={L2425}

  

  Waveguide 'Segment 25'

    Node=33=32

    STh={S26}

    SMo={S25}

    Len={L2526}

  

  Waveguide 'Segment 26'

    Node=33=34

    STh={S26}

    SMo={S27}

    Len={L2627}
       
   
  Waveguide 'Segment 27'

    Node=34=35

    STh={S27}

    SMo={S28}

    Len={L2728}
   

  Waveguide 'Segment 28'

    Node=35=36

    STh={S29}

    SMo={S28}

    Len={L2829}
                                                 

  Waveguide 'Segment 29'

    Node=36=37

    STh={S29}
   
    SMo={S30}

    Len={L2930}

Waveguide 'Segment 30'

    Node=37=38

    STh={S30}
   
    SMo={S31}

    Len={L3031}

Waveguide 'Segment 31'

    Node=39=38

    STh={S32}
   
    SMo={S31}

    Len={L3132}
 

Waveguide 'Segment 32'

    Node=39=40

    STh={S32}
   
    SMo={S33}

    Len={L3233}   

Waveguide 'Segment 33'

    Node=41=40

    STh={S34}
   
    SMo={S33}

    Len={L3334}

Waveguide 'Segment 34'

    Node=41=42

    STh={S34}
   
    SMo={S35}

    Len={L3435}

Waveguide 'Segment 35'

    Node=42=43

    STh={S35}
   
    SMo={S36}

    Len={L3536}
   
   
Waveguide 'Segment 36'

    Node=44=43

    STh={S37}
   
    SMo={S36}

    Len={L3637}
   
   
Waveguide 'Segment 37'

    Node=44=45

    STh={S37}
   
    SMo={S38}

    Len={L3738}
   
   
       
Waveguide 'Segment 38'

    Node=46=45

    STh={S39}
   
    SMo={S38}

    Len={L3839}
   
   
   
Waveguide 'Segment 39'

    Node=46=47

    STh={S39}
   
    SMo={S40}

    Len={L3940}
   
   
   
Waveguide 'Segment 40'

    Node=48=47

    STh={S41}
   
    SMo={S40}

    Len={L4041}
   
   
Waveguide 'Segment 41'

    Node=49=48

    STh={S42}
   
    SMo={S41}

    Len={L4142}
   
   
   
Waveguide 'Segment 42'

    Node=49=50

    STh={S42}
   
    SMo={S43}

    Len={L4243}
   
                       
Waveguide 'Segment 43'

    Node=50=51

    STh={S43}
   
    SMo={S44}

    Len={L4344}
   
   
Waveguide 'Segment 44'

    Node=51=52

    STh={S44}
   
    SMo={S45}

    Len={L4445}
   
           
 Radiator 'Horn mouth'

    Node=52

    SD={S45}

post-5-0-09565400-1386278424_thumb.jpg

post-5-0-57494700-1386278460_thumb.png

post-5-0-28859600-1386278467_thumb.jpg

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The script isn't so bad Mike...What I do is start with a cabinet form or total cabinet volume and extension that I want to stick with or a particular driver and then play around in HR for about 10 min to get a grip on what parameters the driver likes to see that fit within the allotted amount of space. From there I start trying different folds until the path gets close to correct length needed and then I start to tweak the shape of the horn expansion to try and get things closer to ideal for the driver being used. Trial and error...Trial and error. This usually ends up with 3 or even 4 different expansions since I'm often trying to fit the horn in the box instead of building the box to match the horn. Once the fold plan looks workable and a rough HR sim to approximate the folded up horn looks decent I will transfer the whole thing into Akabak with a much more detailed script that is closer to what is actually being built. Usually there is only a few minor differences from HR even with 10X the segments being modeled but ocassionally there have been differences large enough that I went back to the drawing board to tweak some things or even scrapped a design completely.

 

 

Max,

It simulates to perform almost exactly like the original GH so the cabinet loading is 17Hz with full power able to be applied to just below 15Hz. Needs high passed at about 14Hz. The new design does simulate with slightly lower internal pressure and velocities though due to a slightly increased throat volume.

 

I don't know if I will even build these...I have another design that I'm going to call the PaleHorn that has to get done first and by that time I may be done with another design I've been struggling with for over a year so that would be next in line after that. I wouldn't need the GH's at that point.

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Compared to a HR sim, I wouldn't exactly call it simple, but I do generally understand it. I need to brush up on my akabak skills though.

 

I can relate to the trial and error part of things, I just scrapped V3 of my current project (a little 10" loaded cabinet), so I'm on to V4. Close, but not quite. V3 of the fold fits in the space I gave it, the driver fits in the cabinet, and it is an easy build, but the corner is 5 Hz too high, just as I feared it would be. With the driver I am playing with, I can go lower, so that's the plan.

 

When I move to akabak, it is because I can't do what I want in HornResp, or as a check of a HornResp model that I am not convinced is showing me the whole story.

 

Have you seen this software? I've messed with it a bit. Seems like a steep learning curve, but appears to be solid. There is a thread over at DIYAudio discussing its use. 

 

I can relate to the "I don't know if I will even build these" part too. More ideas than time and materials to build things, let alone the need for the finished cabinets. 

 

PaleHorn?? Do tell...

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When I move to akabak, it is because I can't do what I want in HornResp, or as a check of a HornResp model that I am not convinced is showing me the whole story.

 

Have you seen this software? I've messed with it a bit. Seems like a steep learning curve, but appears to be solid. There is a thread over at DIYAudio discussing its use. 

 

I can relate to the "I don't know if I will even build these" part too. More ideas than time and materials to build things, let alone the need for the finished cabinets. 

 

PaleHorn?? Do tell...

 

 

 I do the same...Akabak is my final check to make sure it is something ready to be built.

 

I had seen that software mentioned but haven't tried it. I have tried to get familiar with ABEC but it is like Akabak x3 and just really hardcore with the script dependency to the point that you need a script for everything down to the environment the speaker will be in. I am in no way a scripting guru I know just enough to work out some things in Akabak, but ABEC is far more powerful than even Akabak so it is worth trying to learn. So far it is making me feel like a toddler though so I've been avoiding it.

 

 

Palehorn is the next step past the Othorn...More powerful driver, more output, a tiny bit lower extension, redesigned cabinet and fold, same external footprint. This one will be built.  

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Palehorn sounds awesome. Look forward to the results.

 

I'm playing with pea-shooters in comparison, no $$ for the big toys.

 

With the fuse lit on my remodel, I am about to be PWT for the next couple years, every spare dollar will get poured into the house.

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my first post here.  had to register to view the v2 pic.  :-)  quite nice work there josh. 

 

i'm guessing the pale horn is front loaded with a big bottom end?

 

 

No. It is a tapped horn still. I just cannot get a FLH with that much extension into a cab that size without sacrificing a lot of sensitivity and output 20-40Hz.

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It won't be that bad fitting the driver in really. Actually I should be able to get a 15" deep driver in there. Building the hatches won't be that fun but as far as removing the drivers and replacing them I don't expect that to be bad at all once done.

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  • 4 weeks later...
  • 3 weeks later...
  • 2 weeks later...

Hi Ricci,

I Hope the New design is Not much better..... I use Since 3 month 2 gh !

In the First Januar week i orderd all Wood.... For the next 2 gh Horns.....

The Most Panels now finished, so its too Late for the New design.

 

Is the Resonanz Frequenzes the Same ??

 

Best regards from Germany !!!!

 

By the Way, its a very Great sub for 15-40hz, but i thinked 128db is Louder :-)

So i Need 2 more ;-)

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