LIVE SOUND Specific Tapped Horn thread... - Page 23 - diyAudio
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Old 23rd January 2009, 03:07 AM   #221
FlipC is offline FlipC  United States
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The problem with OSB is resonance. Make sure to brace all panel's.
And look around for it at 5-6 bucks a sheet!

I assume you are using the data from the last pic you posted? 544.668 Lt one? If so take a look at this:

Ang:2 Pi
Eg 2 volt
S1 = 306
S2 = 387.68
CON 1=27.30
S3=3780.24
Con 2=260.2
S4 =3000
Con 3=360.30

That's 417.316 Liters with more usable bandwidth.

Anyway back to the question about the schematic.
In your last response chart pic the driver. Your driver fires freely into the throat. Where as the one I posted has wood covering a portion of the driver.
The schematic is 2D representing 3D space.
So imagine the black lines as a horn in a solid object. The red circle is the driver (of course) and we are looking at it as if it is sitting top down (IE magnet up) firing into a "hole". Since it is a TH horn the green represent the rear of the driver in correlation to the mouth. (distance from)

If you notice in my schematic the driver is "outside" the mouth.
I assumed this would represent an angle to which it should be positioned.
I can assume only Akabak can simulate that? But that is a question for someone other than myself at this point. I am just learning Akabak.
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Old 23rd January 2009, 07:43 PM   #222
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that s4 is smaller than s3 and gives a terrible response with a huge peak at<20hz, are you sure you pasted that right? its also 1694litres.

also, regarding the slot infront of the driver, do you just calculate the surface area of the union between the driver (red circle) and the horn? and thats your slot size?
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Old 24th January 2009, 01:29 AM   #223
FlipC is offline FlipC  United States
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Woops
Not sure what I did there but heres the correct one

Ang:2 Pi
Eg 2 volt
S1 = 306
S2 = 387.68
CON 1=17.30
S3=2780.24
Con 2=260.2
S4 =3000
Con 3=16.1
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Old 26th January 2009, 09:21 PM   #224
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your design, while a fair bit smaller, doesnt seem to have a huge advantage over mine in the high end, and seems to have a somewhat rising response between 100 and 200hz. this at the expense of a bit over a DB of low end sensitivity, the dip between 40 and 100hz remains just as large. also how can i make s1-s2 < the radius of my driver? likewise with s3-s4?

also, the slot is still not clear to me, it is the area of the union made between the walls of the horn and the driver in the "schematic" view right? i must calculate that area, and have a slot infront of the driver that mimics it?

renovations and whatnot around the house have been pushing this toward the abckburner, but i really wanna get it built this week.
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Old 27th January 2009, 10:58 PM   #225
FlipC is offline FlipC  United States
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As long as I am understanding your usage of the word UNION
Then you are correct in your thinking. This needs to be precise as possible.

As far the design.
Just a quick thing to lower the physical size. Also those upper peaks will not be there in the built version. Least from what I have seen in the 3 I have built and what others have posted from their builds. Though mine were not at 100 Hz but rather 150-200.

Even though HR seems to do a good job
at modeling a TH it isn't perfect. It is said that the dip between 40-100 will even out also. My TH's were pretty dang flat in that area so? Somewhere i read Danley talking about modeling with the peaks.
Search you can find it.
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Old 28th January 2009, 09:06 PM   #226
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ive heard alot of this before about peaks flattening out in the actual design, i read danleys little speech on it too. if that dip between 40 and 100hz fills in, then it should be a wicked design.

im probably going to go with my design, as it doesnt really cost more material wise, and this box is going to be far from permenant. not to mention ive always practiced the "fudge it bigger" principle (and whats 100 litres here and there?) when building subwoofers. besides ive already done panel sizes and a design for my model, and all my hornresp time these days is being sucked up by me trying to design something close in performance to a dr200 or omni top 12(got something as good as the omi 12, using a beta 12a driver, but trying to push that driver up to the dr200 sensitivity range is proving to be difficult! how anyone know how BFM makes his maesurements?(sorry for the OT)).

and i think we mean union the same way, i mean it in the grade 6 math venn diagram way.
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Old 28th January 2009, 09:21 PM   #227
FlipC is offline FlipC  United States
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I don't know how any of the companies do their SPL ratings.
I have tried and tried to get either my TH Mini clone or 115 clone to be the same as Danleys and nothing.

I am working on a coaxial design
for tops. Single 10" with a horn loaded 5" or 1" compression.
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Old 29th January 2009, 02:27 AM   #228
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Omnitop huh.....
Close the damn ports (feedback makers) and .....
For a kappa 12 and PV22xt setup......
Loud as heck and blowup resistant.


s1 300
s2 2167
L12 45
VRC 28
LRC 20
FR40
tal 6
VTC 1200
Atc 130

The ATC assumes a central plug over the cone dustcap and on the back of the HF driver and is the area remaining for the sound to travel through around the plug and HF driver.
Couple it to a 1.2k compatable horn driver and you have a pretty decent top. Doesn't go too low unfortunately. The hard part is getting the 12 inch up to meet the horn unless you have 2" drivers.
Wrap the throat chamber around the horn driver so the 12" fires around it to the sides. A phase plug would be ideal as well.
The cabinet shound be 14" to 15" high inside max so they can couple together and the 5x15 horn lenses can be used with thier narrow side mounts removed. This allows retention of the quasi line array properties of the box.
You'll have an easier time with a pair of 10" drivers.
If you go piezo you may get distortion on live vocals including speaking but dj is fine. I had not tried Bill's piezo xover fix as it came out long after my complaining and conversion to PV22xt drivers. I'd love to know if anybody tried it though. (they cost me too many clients to try them again).
The 3 problems I found with the omnitop12 are 1) the chamber not having enough insulation, 2) the ports, 3) the shape of the throat. I'm still using 12 of them.
My site has been pulled down for now so photos are not available.
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Old 29th January 2009, 03:49 AM   #229
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first of, i think another big round of thanks is due, i feel like i kinda hijacked your guysè thread!

this will be used for DJing, but also hopefully for live sound, i was planning on using piezo arrays, but putting them along the side of the cabinet, and building 4(stacking a pair on either side), its only a copy insomuch, that it looks similar, i looked at his design, liked the simplicity and form factor, so i set out making something similar in hornresp. I cant seem to be able to simulate the horn mouth in conjunction with the drivers fr graph (the horn resp sim says pretty much nothing over 700hz, even though the driver is more than 100db/w sensitive on its own over 1khz), i thought of scaling them and laying them ontop of each other....i seem to have been able to achieve 100db+ sensitivity between 100 and 700hz(looking at the fr curve id guess around 102 or 103 between) but this is in 2 pi loading, and mains are usually on stands....

this is all on a budget, so i want to use beta12 drivers, as they have a good balance of powerhandling xmax and efficiency.

so many questions but i feel this would be better in a different thread, these horns are neither subwoofers nor tapped!

anyway, im going to be a stubborn kid and build my deisgn out of 3/4" OSB, as a 585 litre horn, throw some shelf braces in and cross it at 100. once again thank all you guys for your help, i now have far greater understanding of hornresp.

dont think youre off the hook yet though i still have my whole pa to design! this ones just a toy/proof on concept
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Old 29th January 2009, 04:59 AM   #230
jbell is offline jbell  United States
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xstephanx:
for tops... yea, what screamers says. He's been there, done that, and has the battle scars to prove it...

I've done some playing around with tops myself, and come up with a reasonable top on the cheap, using mcm 55-1740's. They wouldn't stand up to what screamers puts them through however...

Screamers -- When do we get to see the final build with your whole setup?
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