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post #1 of 156 Old 07-27-2011, 11:31 AM - Thread Starter
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Here is a tapped horn design intended for pro sound reinforcement type applications, or any just plain old, really loud music apps that I started working on last July and finally finished the design back at the beginning of March. I worked on this in tandem with the Gjallerhorn. I decided to have the Gjallerhorn built first as it was a larger, more complicated, more expensive and risky design. Since it turned out so well I am feeling rather confident about this one. My goals with this design were true 30hz extension with solid useable output to the 25hz range. This is quite a bit lower than the majority of pro bass bins will really reach to despite their ratings. The increasing popularity of down tuned 5 and 6 string bass guitars, bass drops and the prevalance of DnB and Dubstep genres have started to ask for more power than ever from subs in the 25-35hz range. Along with this extension I wanted it to still be able to get quite loud and to retain decent sensitivity. I also decided to use an enclosure form of no larger than 36x36x24" which is large but not out of the ordinary for pro bass bins and comparable in total volume with many double 18" vented subs. A larger 45x45 type of cabinet like the Gjallerhorn or Labsub would've given better efficiency and higher output but these types of cabs are larger and heavier than I want to lug around very often. A pair of these should do most bars or small venues with no problem and 4 should do a good job in a mid sized venue. 2 will fit in the cargo hold of most medium sized suv's.

I already own a pair of B&C 21sw152-4 drivers and Danley has already used them in a couple of tapped horns so it was a no brainer to design around them.

Fast forwarding through about 9 months of design work and revisions here is what the final design will be. I will contract he same cabinet shop that built the Gjallerhorn cabs to do these as well. Unfortunately with everything else going on I don't have the time to build cabs this complicated myself anymore. Besides I could never deliver the build quality that the professionals can.

BTW Thanks to Soho54 for being my sanity checker on this cab design.

Here is the HornResponse and Akabak input data for simulating the cab. This one was also designed in Akabak working backwards from the cabinet size and best fold that would fit in the cab and achieve the right low corner instead of the other way around. I have found this works much easier for me than coming up with a pretty simulation and trying to fold and cram it into a workable cabinet while maintaining the parameters. Once again I use Akabak since there were so many folds, different expansion rates and corners involved. Amazingly the much simpler HR simulation that approximates the final Akabak one is very close. The differences are there but quite small. Not worth worrying about for most people unless you are a stickler like me who is worried about accuracy to the nth degree. Anyway here are the inputs.



NOTE: If you wish to model 18" drivers in this cabinet you should change the value of VTC to 4000 and the ATC value to 1465

HR





Akabak script
|COMMENT: OTHORN B&C 21SW152-4 30hz TH 36"x36"x24" revised 030411 completion(Driver restricts horn by approximately 517cm2 at S32)



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



|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 = 1.86V 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 = 20.397216e-4; |Horn segment 1 throat area (sq cm)
S2 = 400.79072e-4; |Horn segment 1 mouth area and horn segment 2 throat area (sq cm)
S3 = 480.93721e-4; |Horn segment 2 mouth area and horn segment 3 throat area (sq cm)
S4 = 490.40735e-4; |Horn segment 3 mouth area and horn segment 4 throat area (sq cm)
S5 = 499.87748e-4; |Horn segment 4 mouth area and horn segment 5 throat area (sq cm)
S6 = 503.41786e-4; |Horn segment 5 mouth area and horn segment 6 throat area (sq cm)
S7 = 752.67183e-4; |Horn segment 6 mouth area and horn segment 7 throat area (sq cm)
S8 = 525.374e-4; |Horn segment 7 mouth area and horn segment 8 throat area (sq cm)
S9 = 672.07369e-4; |Horn segment 8 mouth area and horn segment 9 throat area (sq cm)
S10 = 1003.4701e-4; |Horn segment 9 mouth area and horn segment 10 throat area (sq cm)
S11 = 706.47214e-4; |Horn segment 10 mouth area and horn segment 11 throat area (sq cm)
S12 = 710.68271e-4; |Horn segment 11 mouth area and horn segment 12 throat area (sq cm)
S13 = 1011.4833e-4; |Horn segment 12 mouth area and horn segment 13 throat area (sq cm)
S14 = 744.03216e-4; |Horn segment 13 mouth area and horn segment 14 throat area (sq cm)
S15 = 827.70445e-4; |Horn segment 14 mouth area and horn segment 15 throat area (sq cm)
S16 = 1148.9606e-4; |Horn segment 15 mouth area and horn segment 16 throat area (sq cm)
S17 = 850.19967e-4; |Horn segment 16 mouth area and horn segment 17 throat area (sq cm)
S18 = 852.58905e-4; |Horn segment 17 mouth area and horn segment 18 throat area (sq cm)
S19 = 1222.0554e-4; |Horn segment 18 mouth area and horn segment 19 throat area (sq cm)
S20 = 876.8326e-4; |Horn segment 19 mouth area and horn segment 20 throat area (sq cm)
S21 = 434.06586e-4; |Horn segment 20 mouth area and horn segment 21a throat area (sq cm)
S22 = 572.31875e-4; |Horn segment 21a mouth area and horn segment 22a throat area (sq cm)|
S23 = 1185.3696e-4; |Horn segment 22a mouth area and horn segment 23 throat area (sq cm)
S24 = 1724.8322e-4; |Horn segment 23 mouth area and horn segment 24 throat area (sq cm)
S25 = 1255.2883e-4; |Horn segment 24 mouth area and horn segment 25 throat area (sq cm)
S26 = 619.44195e-4; |Horn segment 25 mouth area and horn segment 26a throat area (sq cm)|
S27 = 680.54455e-4; |Horn segment 26a mouth area and horn segment 27a throat area (sq cm)|
S28 = 1400.7642e-4; |Horn segment 27a mouth area and horn segment 28 throat area (sq cm)
S29 = 2279.1994e-4; |Horn segment 28 mouth area and horn segment 29 throat area (sq cm)
S30 = 1799.9231e-4; |Horn segment 29 mouth area and horn segment 30 throat area (sq cm)
S31 = 1805.1536e-4; |Horn segment 30 mouth area and horn segment 31 throat area (sq cm)
S32 = 1411.3236e-4; |Horn segment 31 mouth area and horn segment 32 throat area (sq cm)/(1411.3236cm restricted by driver (estimated),1928.3236cm ignoring driver in path)
S33 = 2043.1017e-4; |Horn segment 32 mouth area and horn segment 33 throat area (sq cm)
S34 = 2057.0009e-4; |Horn segment 33 mouth area and horn segment 34 throat area (sq cm)
S35 = 2260.638e-4; |Horn segment 34 mouth area (sq cm)

L12 = 27.504644e-2; |Horn segment 1 axial length (cm)
L23 = 27.258518e-2; |Horn segment 2 axial length (cm)
L34 = 3.070098e-2; |Horn segment 3 axial length (cm)
L45 = 3.355594e-2; |Horn segment 4 axial length (cm)
L56 = 1.203198e-2; |Horn segment 5 axial length (cm)
L67 = 3.625088e-2; |Horn segment 6 axial length (cm)
L78 = 3.781298e-2; |Horn segment 7 axial length (cm)
L89 = 41.853612e-2; |Horn segment 8 axial length (cm)
L910 = 4.81838e-2; |Horn segment 9 axial length (cm)
L1011 = 5.029708e-2; |Horn segment 10 axial length (cm)
L1112 = 1.20142e-2; |Horn segment 11 axial length (cm)
L1213 = 4.740656e-2; |Horn segment 12 axial length (cm)
L1314 = 4.877562e-2; |Horn segment 13 axial length (cm)
L1415 = 37.930582e-2; |Horn segment 14 axial length (cm)
L1516 = 5.453888e-2; |Horn segment 15 axial length (cm)
L1617 = 5.582412e-2; |Horn segment 16 axial length (cm)
L1718 = 1.20269e-2; |Horn segment 17 axial length (cm)
L1819 = 5.869432e-2; |Horn segment 18 axial length (cm)
L1920 = 6.282436e-2; |Horn segment 19 axial length (cm)
L2021 = 1.371346e-2; |Horn segment 20 axial length (cm)
L2122 = 46.972982e-2; |Horn segment 21a axial length (cm)
L2223 = 2.97434e-2; |Horn segment 22 axial length (cm)
L2324 = 7.91972e-2; |Horn segment 23 axial length (cm)
L2425 = 8.488172e-2; |Horn segment 24 axial length (cm)
L2526 = 2.246376e-2; |Horn segment 25 axial length (cm)
L2627 = 30.794452e-2; |Horn segment 26a axial length (cm)
L2728 = 2.872232e-2; |Horn segment 27 axial length (cm)
L2829 = 11.00836e-2; |Horn segment 28 axial length (cm)
L2930 = 10.296144e-2; |Horn segment 29 axial length (cm)
L3031 = 1.199134e-2; |Horn segment 30 axial length (cm)
L3132 = 27.93238e-2; |Horn segment 31 axial length (cm)
L3233 = 26.647902e-2; |Horn segment 32 axial length (cm)
L3334 = 3.189478e-2; |Horn segment 33 axial length (cm)
L3435 = 6.672834e-2; |Horn segment 34 axial length (cm)

Vtc = 7400e-6; |Throat chamber volume (cc)(Estimated)

Atc = 2026.00e-4; |Throat chamber cross-sectional area (sq cm) (Estimated)



|Parameter Conversions:



Sd = 1680.00e-4; |Diaphragm area (sq cm)



Ltc = Vtc / Atc;

}

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



|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-Radiator



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



Def_Driver 'Driver'



Sd=1680.00cm2

Bl=32.57Tm

Cms=5.35E-05m/N

Rms=13.28Ns/m

fs=32.0001Hz |Mmd = 422.82g not recognised by AkAbak, fs calculated and used instead

Le=1.50mH

Re=3.40ohm

ExpoLe=1



System 'System'



Driver Def='Driver''Driver'

Node=1=0=5=39



Duct 'Throat chamber'

Node=5=9

SD={Atc}

Len={Ltc}

Visc=0



Waveguide 'Segment 1'

Node=8=9

STh={S1}

SMo={S2}

Len={L12}



Waveguide 'Segment 2'

Node=9=10

STh={S2}

SMo={S3}

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=12=13

STh={S5}

SMo={S6}

Len={L56}



Waveguide 'Segment 6'

Node=13=14

STh={S6}

SMo={S7}

Len={L67}



Waveguide 'Segment 7'

Node=15=14

STh={S8}

SMo={S7}

Len={L78}



Waveguide 'Segment 8'

Node=15=16

STh={S8}

SMo={S9}

Len={L89}



Waveguide 'Segment 9'

Node=16=17

STh={S9}

SMo={S10}

Len={L910}



Waveguide 'Segment 10'

Node=18=17

STh={S11}

SMo={S10}

Len={L1011}



Waveguide 'Segment 11'

Node=18=19

STh={S11}

SMo={S12}

Len={L1112}



Waveguide 'Segment 12'

Node=19=20

STh={S12}

SMo={S13}

Len={L1213}



Waveguide 'Segment 13'

Node=21=20

STh={S14}

SMo={S13}

Len={L1314}



Waveguide 'Segment 14'

Node=21=22

STh={S14}

SMo={S15}

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=28=27

STh={S21}

SMo={S20}

Len={L2021}



Waveguide 'Segment 21'

Node=28=29

STh={S21}

SMo={S22}

Len={L2122}



Waveguide 'Segment 21b'

Node=28=29

STh={S21}

SMo={S22}

Len={L2122}



Waveguide 'Segment 22'

Node=29=30

STh={S22}

SMo={S23}

Len={L2223}



Waveguide 'Segment 23'

Node=30=31

STh={S23}

SMo={S24}

Len={L2324}



Waveguide 'Segment 24'

Node=32=31

STh={S25}

SMo={S24}

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 26b'

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=36=35

STh={S28}

SMo={S29}

Len={L2829}


Waveguide 'Segment 29'

Node=36=37

STh={S30}

SMo={S29}

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=40=41

STh={S33}

SMo={S34}

Len={L3334}


Waveguide 'Segment 34'

Node=41=42

STh={S34}

SMo={S35}

Len={L3435}

Radiator 'Horn mouth'

Node=42

SD={S35}
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post #2 of 156 Old 07-27-2011, 11:36 AM - Thread Starter
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Here is some images of the cabinet design which was done in SolidWorks.









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post #3 of 156 Old 07-27-2011, 11:39 AM
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Ah, yes. I've been waiting out for this one.

Pretty much a horn version of your vented B&C 21" project, yes?

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post #4 of 156 Old 07-27-2011, 11:41 AM - Thread Starter
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Schematic diagram




Phase



Acoustic Impedance



Impedance




Basic response 1w/1m 1.86v input half space
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post #5 of 156 Old 07-27-2011, 12:01 PM - Thread Starter
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This enclosure should be able to take brief 120v input peaks anywhere above 24hz without risk of damage. Roughly 4200w into the minimum impedances in the pass band. This lines up pretty well with what some of the larger touring amplifiers on the market are rated at into 4ohm stereo loads. At that power level the cone excursion reaches 20mm at the in band excursion peak and at 24.5hz. I know from using these drivers and testing them that this is about the point where they get non linear and start to make suspension noises. Additional input power does not produce much further excursion with these drivers as the motor force is drastically reduced and the suspension is uber tight. An input of about 95volts puts the cone excursion right at xmax between 15-16mm. Also a 25hz 24db octave Butterworth hpf will be used on these since cone excursion sky rockets below 25hz as the driver unloads.

All of the simulation data below is at 120v input.









Akabak power density



HR Excursion 120v





Akabak excursion 120v





Power applied






Current applied





Velocity






Volume Velocity






Acceleration






Pressure






Force









120v input 1m fullspace or 2m halfspace response. The response cuts off where the cone excursion breaks 20mm. Add 6db for 1m half space 120v output
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post #6 of 156 Old 07-27-2011, 12:26 PM - Thread Starter
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If anyone wants the plans for this cab I have a cnc type Autocad print made up as well as a SLDDRW print and a PDF print of the cabinet plans. It should be enough to build it or adapt it for your own needs if anyone has a need of a cabinet like this. You will have to pm me your email address as the prints are too big to attach here.

Additionally there are other drivers that should also work very well in this cab.

TC Sounds Pro5100
18Sound 21NLW9600
18Sound 21NLW9000C
18Sound 18NLW9600
18Sound 18NLW9600C
18Sound 18W1000
B&C 18NW100
B&C 18SW115
B&C 21SW150
B&C 21sw152-8 (8 ohm version looks ok, but not as good as the 4 ohm.)
Beyma 18SW1600ND
Faital 18XL1500
Faital 18XL1600 (This one doesn't look as good as the 1500 but it could be a new model.)
Fi Car Audio BTL N2 18d2 ( It does not look as smooth as some of the others and it is a little less sensitive, but excursion would never be an issue with its 30mm xmax and 40mm xmech. Might be worth trying if someone is crazy enough.)
SSA Zcon 18d2 (See BTL notes.)








When the subs are complete I will do a full outdoor ground plane test session on them. That will be a few months from now though.
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post #7 of 156 Old 07-27-2011, 02:01 PM
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Very thorough, VERY nice!!!

JSS
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post #8 of 156 Old 07-27-2011, 02:39 PM - Thread Starter
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Scott how the hell did you sneak that response in there?

Thanks Max. Information overload...
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post #9 of 156 Old 07-27-2011, 03:09 PM
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Heheh, sorry. I can delete it if you want some continuity with your initial post.

I just saw your thread and had to check it out.

Killer design work, Ricci. You should be getting paid for this.

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post #10 of 156 Old 07-27-2011, 03:37 PM
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Great post Ricci. You've really covered all the bases Have you ever modelled the TD18H or the MaelX gen2 in this cab design? For this design, would the lower Fs of the chosen driver result in a lower f3?

ps. very sneaky Scott!! When celebrities are being photographed I am sure you are the other person in the frame

explore the music
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post #11 of 156 Old 07-27-2011, 04:00 PM
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Nice Job Josh. Well thought out, with some very sound engineering.

But one heavy cabinet!

You know how much it will weigh?

You check out the air velocity option in hornresp?

It shows this for enough wattage to melt the driver!

Attachment 218538

May address some of the horn packing up issues we face. I'm going to be testing the air speed velocity issue on some other prototypes to see what is going on. If it checks out to be accurate it will be quite a powerfull tool in high volume applications.


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post #12 of 156 Old 07-27-2011, 08:30 PM
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Nice looking monster you've conjured up there.

Looking forward to the real-world testing.
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post #13 of 156 Old 07-28-2011, 04:04 AM
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I am assuming this is all 3/4" material?

I am assuming it will be heavy but just wondered what thickness. Some of the angles look pretty difficult on the drawing but maybe it is easier then it looks?

I am sure there other variable involved but did you move where the response curve drops to aid in minimizing excursion?

I know my sim on my response dropped after 27/28hz but I had to push the excursion to 22mm. And the 22/22hz was looking like 30mm excursion. This is all at 116v(1700watts). I put the BC 18SW115 in your horn and it seems to be pretty close to what you have except the excursion is a mm or two less and it hits 30mm around maybe 22.5hz.

You have done all the hard work here so I might as well just build your TH. I am just trying to figure out how to get better at modeling TH's for given drivers.

I wont have my 18" for another month, BUT I think I will just build your TH if I can figure out what I need to cut. Cant afford anyone to CNC the parts .......BUT that would be nice.

PM sent

I forgot to ask, Does the 21" outperform the 18" BC by much?

I would love to buy the 21" but that would cost me about 250 more dollars than the 18". Either one will be overkill but thats the point.
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post #14 of 156 Old 07-28-2011, 06:10 AM - Thread Starter
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Quote:
Originally Posted by Antripodean View Post

Great post Ricci. You've really covered all the bases Have you ever modelled the TD18H or the MaelX gen2 in this cab design? For this design, would the lower Fs of the chosen driver result in a lower f3?

I modeled every current 18" and 21" driver in my Winisd data-base in it including those 2. Neither of them work in this cab.

To the second part of your question, horns don't work like that. The F3 might change slightly with a different driver but the more important thing is where the driver unloads from the horn and that will not change. No driver will get much 20hz out of this cab. It simply isn't made for it.
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post #15 of 156 Old 07-28-2011, 06:15 AM - Thread Starter
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Quote:
Originally Posted by mwmkravchenko View Post

Nice Job Josh. Well thought out, with some very sound engineering.

But one heavy cabinet!

You know how much it will weigh?

You check out the air velocity option in hornresp?

It shows this for enough wattage to melt the driver!

Attachment 218538

May address some of the horn packing up issues we face. I'm going to be testing the air speed velocity issue on some other prototypes to see what is going on. If it checks out to be accurate it will be quite a powerfull tool in high volume applications.


Mark

Thanks Mark.

I don't think it will be that heavy. I will build it all out of BB. The driver is 46lbs and I figure maybe 110lbs of wood? I don't know that is a guess but I would expect the whole thing to come in under 180lbs easy. Now the Gjallerhorn that is heavy.

I had read that he had added that to HR just yesterday but I haven't updated HR in awhile. I am still on version 28.30. Looks like I should update.
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post #16 of 156 Old 07-28-2011, 06:42 AM - Thread Starter
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Quote:
Originally Posted by chrapladm View Post

I am assuming this is all 3/4" material?

I am assuming it will be heavy but just wondered what thickness. Some of the angles look pretty difficult on the drawing but maybe it is easier then it looks?

I am sure there other variable involved but did you move where the response curve drops to aid in minimizing excursion?

I know my sim on my response dropped after 27/28hz but I had to push the excursion to 22mm. And the 22/22hz was looking like 30mm excursion. This is all at 116v(1700watts). I put the BC 18SW115 in your horn and it seems to be pretty close to what you have except the excursion is a mm or two less and it hits 30mm around maybe 22.5hz.

You have done all the hard work here so I might as well just build your TH. I am just trying to figure out how to get better at modeling TH's for given drivers.

I wont have my 18" for another month, BUT I think I will just build your TH if I can figure out what I need to cut. Cant afford anyone to CNC the parts .......BUT that would be nice.

I forgot to ask, Does the 21" outperform the 18" BC by much?.

This is mostly 18mm (3/4) material, but the inner panels are 12mm or 1/2". The braces can be either 1/2" or 3/4" but 3/4" is probably best. The driver mounting baffle is also 3/4". There are only 5 pieces of 1/2" material. One of them could be made 3/4" with no problem. (The angled piece near the throat). The other 4 you could probably make 3/4" as well if you wanted without much effect truthfully.

The angles aren't too bad. I made this to be CNC'd originally and put together as a kit so there is way too much detail in there really. Soho54 kept telling me I was sweating the details too much. It makes it look harder than it is. The angled throat panel and the angle by the mouth will be the hardest parts. Other than that it shouldn't be too much harder than a THT. I would trace out the horn path on one side panel and build it from the inside out adding the braces in as you go. As I mentioned it does not have to be perfect just make sure the horn path is the same and everything is solid and sealed well and it will be ok.

The B&C drivers will not go past about 20mm excursion. Neither of them. That is about the point that they start to make some bad noises too. So I use that as the "everything it's got / running it ragged" output level. This cab had the minimum excursion notch right at 29-30hz and it can provide good output to 25hz. That is also where maximum amplifier power is delivered. You would want a 24db octave 25hz BW hpf on it from there. The 18sw115 has nearly the same efficiency as the 21. The difference is that the 21 uses less excursion to do the same work. The 18sw115 has an RE of 5.3 versus the 21's RE of 3.4 so it needs more voltage to reach a comparable power input. Right about 115v input looks like the maximum for the 18sw115 and that translates into 2,450w into the minimum impedance. That results in 20mm excursion at the excursion maxima and it exceeds 20mm again at 25hz. The 21 is receiving about 4200w with 120v and produces nearly the exact same excursion levels. It is producing roughly 3db more output at that point.

Basically at the end of the day the 21 offers 3db more headroom and a little more powerhandling. I've attached some comparison data. Light grey is the 21.



Attachment 218583

Attachment 218584

Attachment 218585
LL
LL
LL
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post #17 of 156 Old 07-29-2011, 11:08 AM
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I'll have to remember these. I will most likely need some new garage speakers in about 9 months time.
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post #18 of 156 Old 07-30-2011, 09:53 PM
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Ricci is the other file you sent used for CNC machine?

I dont have anything to open the file with so I figured it might be.
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post #19 of 156 Old 07-31-2011, 10:20 AM - Thread Starter
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Quote:
Originally Posted by chrapladm View Post

Ricci is the other file you sent used for CNC machine?

I dont have anything to open the file with so I figured it might be.

It's just an Autocad file. You don't need it so don't worry about.
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post #20 of 156 Old 07-31-2011, 12:11 PM
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nice work there. looks like you hit your target.

what advantage does the angled slat of wood at the driver provide?

there has to be some way to eliminate the ~115hz peak. any thoughts on that?

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post #21 of 156 Old 08-01-2011, 07:09 AM
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I will start to build the cabinet in the next few weeks. I will have to try and see how it would cost to have someone cnc the parts. Maybe possible for myself and that would make things alot easier.

EIther way thanks Ricci.

I am wondering what would be a good option to power this TH with?

I was looking at the clone LG amp but would still need a Hpas. But then I was looking at the Inuke amps from Behringer and I think they have a Hpas built in them. Dont know so I figured best to ask you which you think would be better.

I still have to try and see if I want to send the extra $200 for 3db or not. VERY VERY VERY tempting but we will see.
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post #22 of 156 Old 08-01-2011, 09:55 AM - Thread Starter
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Ltd02,

The angled piece back in the throat improves the >100hz smoothness a little. The small angle of extra expansion near the mouth provides just a tiny bit of extra sensitivity >60hz and it would be dead space in the cab otherwise.


The peak at 115hz is the 5th harmonic of this particular horn. All TH's have this inherently. It moves depending on the path length and loading of the cab. The closer to fullsized for the wavelengths involved the horn is and the better the driver match the less high Q the peak is and the lower in magnitude. This one actually should be pretty good. Also the simulations always assume perfect walls, sealing and loading so in reality the magnitude of the peaks is often slightly less. The only way that I know of to completely eliminate this is with a tuned resonance cancellation. This is what Tom did in the dts-20. Tom can pull this off but I am not knowledgable on the subject and I suspect it takes quite a bit of trial and error even for Tom and his team. A bit of eq will have to suffice for us.


Chrapladm,
You need a 25hz either 18db or 24 db octave high pass if you will be putting a lot of power to the cab. I would go fo a 24 db octave Butterworth if possible. Doesn't really matter how you supply it. I would shoot for the range of 1000-4000w rated amplifier power if using the 21. If the 18 you don't need more than about 2,500w to get everything out of it. 1000w would not be underpowering it too bad.

Arent the Behringers and Peavey's still pretty much vaporware?
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post #23 of 156 Old 08-01-2011, 02:43 PM
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Hi Ricci,
Mr. McBean has unleashed new Hornresp 28.6.... Now with throat pressure... muhahahah

Looks like you have ~172dB throat SPL, das really LOUD dude

Regards,
Dan
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post #24 of 156 Old 08-01-2011, 02:58 PM
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Is that the kind of SPL you would inside a horn like this? Wow.

My Dual 18" LLT subs 120dB down to 10hz

 

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post #25 of 156 Old 08-01-2011, 04:28 PM - Thread Starter
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Quote:
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Hi Ricci,
Mr. McBean has unleashed new Hornresp 28.6.... Now with throat pressure... muhahahah

Looks like you have ~172dB throat SPL, das really LOUD dude

Back to the drawing board then. We are trying to make a real man's bass bin here. I thought we might be able to get some output out of this thing. I apologize for this pathetic attempt!
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Into the corner with you Josh!

More output in there anyway!!

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post #27 of 156 Old 08-01-2011, 04:35 PM - Thread Starter
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On a serious note pehaps that sort of pressure would explain why the tapped horns seem to hit a wall in the output.
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post #28 of 156 Old 08-01-2011, 04:38 PM
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Yep.

That is most probably the case.

When you run both a particle velocity check and a pressure check it get pretty fast and high.

On a bit of a depressing note the box you designed is only 3 db more efficient that an equivalently sized ported box.

Some drivers are not that tapped horn friendly.

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post #29 of 156 Old 08-01-2011, 05:23 PM - Thread Starter
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Quote:
Originally Posted by mwmkravchenko View Post

On a bit of a depressing note the box you designed is only 3 db more efficient that an equivalently sized ported box.

Some drivers are not that tapped horn friendly.

Good thing this isn't one of those. LOL.

What exactly are you looking at as far as a ported enclosure? If you start looking at 2 18" or 2 21" drivers you can get close and of course if you double the power they will even better it. This beats out an equivalent ported sub with the same driver by a good 4-6db. This is all about power density within the cabinet size of 24x36x36. Within that size restraint you cannot do much better while maintaining the same corner. We can do all sorts of crazy things if we remove the size restriction.
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Attachment 218917


One to one. Same internally sized enclosure.

There is a gain in your design. Just not that much.

The trough in the vented design can be massaged a bit by vent tuning.

The inputs are below:

Attachment 218921
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