Read this thread "scale a wo" This has great stuff on scaling.
https://www.decware.com/cgi-bin/yabb/YaBB.cgi?board=Wicked;action=display;num=11...
anything is possible especially on this forum!
I would be heavy for a DB.

What and where are you using it for?

and wait for pigion droppings he's one smart bird ( inside joke intended to ruffle feathers in fun)

Gex

ahah the DB15 is what you seek?  hrmm... design this we can, sub specs we need.   Start with normal 12 DB I would, then modify it to fit 15 inch.  Do this by keeping the circle hole in baffle same size, and enlargeing everything else to fit the 15.  Directs the sound, the circle hole does.  10 inch diameter it must be to keep baffle working correctly.  The 10 and 12 inch DBs' baffles are almost exactly the same from the circle hole in the 12 past and the main baffle piece in the 10 on back.

I believe this 10 inch hole in 12 inch version makes the air move the same as in the 10 inch DB, therefore the porting will work.  

Now the moon or thong cut out.  This is a problem, I would figure the Surface area of the 10 inch hole, and area of the 12 inch hole and relate them in a ratio:
10PA : 12PA   (SA = Port Surface Area)
-----   -----
10CA : 12CA   (CA = Cone Surface Area)

yeah I was having fun.  so If Tyranacide is around and wants to figure out the area of the thong port of the db12 and the moon port of the db10....

[quote author=J_Rock  link=1126628925/0#5 date=1126735746]yeah I was having fun.  so If Tyranacide is around and wants to figure out the area of the thong port of the db12 and the moon port of the db10.... [/quote]

I thought I mentioned in that post... the exact shape for any exponential port is not that important.... geez. As for a simplistic way to design try this.....
2 nails, a string, and a pencil,
tie string in loop,
place over 2 nails,
pull string tight with pencil( point down )
move pencil in counter clock wise direction for ...
elipse/oval/4 parts of an exponential shape...
OR move pencil in clockwise direction and it will draw out the smile on Yodas face, it will......LOL

Really now, only a few tries with nail spacing and string legnth on scrap paper will suffice to get the size you need...without any math whatsoever. It's the average guys math avoidance trick

That's the way my grandfather with his 6th grade education did it for all the fancy furniture shapes he designed and built. It works!

Guys,

That seems like a lot of really descriptive free info for a set of plans offered for sale, here. Maybe I'm wrong, but I think we're going too far. A scaling formula is one thing, but I think a drawing and measurements is a bit much.

[quote author=J_Rock  link=1126628925/0#10 date=1126986800]no, you would scale the baffle of the 12 inch db up to fit the 15, except you are gonna need to move the circle hole of the 12db, the 10 inch diameter, down to make room fo rthe 15's basket:



length B would be determined by scaling length C, and length A by the height and size of your 15 inch woofer.

Also notice hole in 15 baffle is same size as 12, which is the same size as a 10db baffle hole.

(sorry about scale)

Tyranacide, I was wondering if you could scale the 12 inch port to the size of a 15 port? based on the area if the 10 inch port and the 12 inch port.  
10 inch area= X    
12 inch area = Y    
15 inch area = Z    

X : Y as Y : Z kinda thing? [/quote]

Sorry J Rock, but you seem to have lost me a little i think...

The length for A & C of the 15DB would have to be the length of a 12DB length B scaled by the depth of the subwoofer... slightly confused.. ???

Also so does everyone thing a thong port is better then a arc port on a 15DB....

I have scaled up the plans in an autoCAD program and  have only the port to work out and the size and depth of the length A and C as J rock says..but at the mo, bit lost  :'(

Oh man I totally messed that up is why you are confused! haha I am a dork.

length A is B scaled up.
length c is the shortest possible with you woofer.

Sorry about that I hav eno clue what I even typed before.


I think the 10 inch hole is plenty for the output of the 15.  I mean, its just there to channel the air the same way the 10db does.  If anything, you could cut several pieces and put different size holes in them....

that would be seriously Ill!  that is, if perspex is see through and anybody still uses the term ill....

don't forget there will be a a hair plus a  1/4 differance between the 3/4 MDF and 25mm..
Some forget about centering the port because of the 3/4. With the odd size material on one side may effect a the port and a square box.

Just in case you may have overlooked it.

I am really interested in how your 15 turns out and how big the thing is.  

Gex

thats it? you are all just gonna assume I am right and do it? wow....this is a first.

Where is this beast slick?  pics of the construction process?

well this thread went dead .................

but check it....  

im gonna buy the plans for a deathbox....
& i happen to remove 4 15" kicker L5's out of a truck & replaced them with mtx 9500's....
2 where sold but i have 2 just setting in the shop....
what do u guys think about them for my home audio?
i have a earthquake pro800 amp to power them with witch is 1100rms@4ohms bridged. the L7's are dual 4ohm coils.  

im kinda lost on this "scaling" someone want to help me out?
size is not a matter as it well be in a living room

Or maybe consider an Imperial SO.  A pair look really nice.

It all depends on the sensitivity level, frequency response and level of build difficulty you are looking for.

Is it mainly for HT or music?