Gjallerhorn

[Josh Ricci]

Thanks 18hurts. I doubt that it would make a whole lot of difference with the frequencies involved with this cab but you just never know without trying it.

Imax's and most regular theaters seem to use bass reflex's still, usually tuned near to 25hz. JBL's seem to be popular. I own pair of 2242h's in theater cabs btw but I forget the model #. It has the single 8" port. Anyhoo a few of the Gjallerhorn would be a large improvement over what I have heard cover the bass in any commercial theater. 4 cabs will provide theater reference LFE levels anywhere between 15-120hz at a 10 meter distance outdoors.

 

[weltersys]

I have noted the explosive growth of line arrays, do you think the much lighter weight of BR works better with that setup? As far as physically moving speakers around, BR has it over horns when it comes to ease of moving the lighter cabinets.

Other than some tiny all cone line arrays, most all are horn loaded in the high and mid range, and a few are horn loaded in the low range also.

Most line arrays are "full range" meaning response to 100 Hz or lower, a horn large enough to do that range well needs to be larger than the line array format lends itself to, so BR is usually used for the lower range.

 

[Josh Ricci]

CEA2010 distortion data

Here are the CEA2010 distortion results to go along with the basic output spl numbers.


Gjallerhorn CEA2010 output. Referenced to 2 meters, rms, outdoor groundplane.

10hz-----90.2db
12.5hz---105.2db
16hz-----118.3db
20hz-----122db
25hz-----124.9db
31.5hz---125.8db
40hz-----128.4db
50hz-----127.2db
63hz-----130.2db
80hz-----130.9db
100hz----131.1db
125hz----123.6db

Here is 10hz distortion at just about maximum output. Obviously this is not clean or a passing result. This is way below the cab loading and the distortion is very high, but it shows what the Gjallerhorn can do dynamically down that low before getting the driver into mechanical trouble.

93.2db at 10hz

 

[454Casull]

Did you happen to take measurements with the peaks notched out? Since the waterfall and spectrogram look great already, I'm guessing they would become almost perfect if the response is equalized to near-flat or flat.

I'm in favor of measuring systems in as-tuned setups, rather than raw, but I doubt anyway that the peaks make a big difference either way (if used as a true sub).

 

[Josh Ricci]

I plan to do an equalized set of tests at some point I just haven't had time. Also I discovered that some of the compression was actually due to the m30 microphone.

 

[BP1Fanatic]

Since the waterfall and spectrogram look great already, I'm guessing they would become almost perfect if the response is equalized to near-flat or flat.

+1!

 

[nephylum]

anybody got the plans for this design? im looking to build asap

 

[stewin]

all the plans are here at the below post # 53 pg 6 http://www.diyaudio.com/forums/subwoofers/189784-gjallerhorn-6.html#post2620010

 

[ßart West-VL.]

How would a Monacor SPH 450TC perform in the Gjallerhorn?

 

[Josh Ricci]

How would a Monacor SPH 450TC perform in the Gjallerhorn?

All of the HR inputs for the cab are back at the beginning of this thread. Plug in the driver parameters and try it.

Without looking I would say it is doubtful. This cab needs a lot of motor force on the driver and a lot of displacement.

 

[Josh Ricci]

Gjallarhorn v2 is finalized.

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 (First pic) 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}

 

[jbell]

I like the fold a lot.

however, won't motor noise actually increase, as the port is directly pointing at the horn mouth, instead of at a panel?

I've actually resorted to motor diapers on some designs, spandex and a bit of acoustical cotton spaced a short distance away from the port.

 

[Josh Ricci]

I like the fold a lot.

however, won't motor noise actually increase, as the port is directly pointing at the horn mouth, instead of at a panel?

I've actually resorted to motor diapers on some designs, spandex and a bit of acoustical cotton spaced a short distance away from the port.

Ok...You got me. When I started the redesign process I had a completely different fold from this that I thought would work and the motor was a little further back in the path and with a much different orientation around a corner. As usual something had to be compromised and that was far down on the list of priorities. Actually motor noise has never been a problem at all but some other drivers are not as quiet in operation.

 

[BP1Fanatic]

Wow, 44 segments! Kinda makes HR look really simple.

 

[ßart West-VL.]

Is it possible to see a side by side comparison of the two frequency predictions, please?
Later on, maybe a measured comparison? ^.^

 

[chrapladm]

I figure I will just ask here. The simulation looks fine but is there any reason the Fi 18Q cant be used in this horn Ricci?

 

[DrDyna]

The new version looks a lot more simple to build, assuming the inside "C" panels can be built square and then just mounted to achieve the angles.

Man, I wish I had a pair of these drivers.

 

[Josh Ricci]

No a Fi Q will not perform optimally in this cab.

 

[SpinMonster]

Are plans available with easy to read measurements?

 

[SpinMonster]

If anyone wants a build print for this cab in pdf form either to build or for curiosity sake alone send me your email in a pm. The print is intended for a wood shop to use with a cnc, but all of the information is there to make any modifications necessary.

Your inbox is full.

Is there a difference in outside dimensions for the old vs new versions?