TH-18 Flat to 35hz! (Xoc1's design)

This was effective:
DSCN4571.jpg
 
Hi,:D
If anyone would like to help me out with a sim or hornresp here is what I change all the other measurements are the same,THANKS in advance,any help I can offer just ask!
Thanks alot,:):):):):)
NS
Hi Nosmoking I tried to set out your dimensions for the throat mods but there is something that does not add up. The pic shows a 138 dimension but this seems to be wrong. :confused: Can you recheck and add some extra dimensions if possible. I assume the 112 flat piece is positioned central to the baffle cut out?
Regards
Xoc1
 

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That looks good. I'll do that before I paint them. I didn't want to do it before testing so that in case I had to take out the driver it would be easy

The Vee brace was something I came up with after seeing a frequency based analysis of the speaker model.
http://www.diyaudio.com/forums/subwoofers/190635-th-18-flat-35hz-xoc1s-design.html#post2601928
The biggest fundamental resonance in the cabinet is the horn mouth. The Vee brace counteracts this. With careful positioning removing the driver is still practical.
Of course the alternative is to fit a metal grille. but the bracing is an option for people who are not worried about party animals, or have no metalwork facilities.
I enjoyed watching your video. It is quite humbling to see people from all over the planet build someting I drew up.
I hope you continue with your measurements of the speakers you built. You will need to measure at a greater distance than 1 metre as you are maxing out your db meter!
Each doubling of the distance will give you an extra 6db measuring headroom. 100db at 200 feet (60.96m) is 135.7 db@ 1m :D
Regards Xoc1
 
I hope you continue with your measurements of the speakers you built. You will need to measure at a greater distance than 1 metre as you are maxing out your db meter!

I plan to take 10 meter measurements once all four are done and I figure out how to make my macbook use the Behringer sound card as input so I can use the SPL meter.

Of course the alternative is to fit a metal grille. but the bracing is an option for people who are not worried about party animals, or have no metalwork facilities.

I would like to do this but I have yet to find a source that would be cheap enough to do all 4 for a reasonable source. Any ideas?

135.7 db@ 1m

:D:D:D:D:D

That's about what I model on my computer at the power I was running so that makes me feel good haha
 
You can get metal grill material from PE

And you can bend it over a plywood form if you use some simple metal forming principles.

Clamp it firmly to the form, and whack it with a soft faced hammer, a dead blow hammer is better. You need to notch the corners so that everything meets up correctly but it is not really all that difficult.


You just finished making a rather complicated box, what yah afraid of now?


;)
 
You can get metal grill material from PE

And you can bend it over a plywood form if you use some simple metal forming principles.

Clamp it firmly to the form, and whack it with a soft faced hammer, a dead blow hammer is better. You need to notch the corners so that everything meets up correctly but it is not really all that difficult.


You just finished making a rather complicated box, what yah afraid of now?


;)

It's not the difficulty of it its the cost. If I remember right pe grills are like $50
 
Hi Nosmoking I tried to set out your dimensions for the throat mods but there is something that does not add up. The pic shows a 138 dimension but this seems to be wrong. :confused: Can you recheck and add some extra dimensions if possible. I assume the 112 flat piece is positioned central to the baffle cut out?
Regards
Xoc1

Hi,
You are correct I swapped them,I used a templet to align screw holes when the side went on and that's were I got the measurements from :D I should have made a drawing,but impatient,lol.Sorry for the mix up!
NS
 
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